Hardware ideas for real Bangkok challenges
Connect physical devices to local needs. Explore hardware ideas with a real challenge, a proposed approach and tools to start with.
Food and markets
- Hardware and sensors
Alms Bell: a big button the temple boy presses when there is leftover food
In Chinatown the alms food is so much that temple boys and carts carry it away. A large button in the temple kitchen sends a text to a list of neighbors who signed up, saying how many portions are left and for how long, so food goes to people instead of the bin.
Build with ESP32, arcade button, SIM800 or Wi-Fi SMS API, Google Sheets
People who run out of money for food can't find where a free meal is today
- Hardware and sensors
Oil Light: a dip probe that turns red when frying oil is spent
A stall owner dips a small probe into the wok at closing. An ESP32 reads how the oil conducts electricity and lights green, yellow or red against a color chart the team calibrates on fresh, once-used and black oil. The owner stops guessing by color and smell.
Build with ESP32, 2-pin dip probe, 3 LEDs, 18650 battery
- Hardware and sensors
Passer Counter: a counter at the stall that compares people passing with people buying
A cheap infrared sensor counts people passing and a big button counts sales. An e-ink screen shows conversion by hour, so the seller learns whether the problem is nobody stopping or nobody buying.
Build with ESP32, PIR or IR sensor, button, e-ink 2.9 inch
- Hardware and sensors
Auto Discount Sign: an e-ink sign that drops the price at 8 PM and counts portions
An e-ink sign on the stall shows the price and portions left. At a set hour it switches to a discount automatically and a counter button updates the number, so leftovers turn into sales without the seller doing anything.
Build with ESP32, e-ink 4.2 inch, button, RTC
- Hardware and sensors
Closing Button: one press at closing prints rescue bag stickers with a QR
At 8 PM the cafe owner bags the six leftover pastries, presses one big button and the thermal printer prints a rescue sticker with a QR and a pickup window. Neighbors scan to claim, and the first one to claim sees a pickup code. Donating takes ten seconds, not a phone call.
Build with Raspberry Pi Zero 2 W, thermal printer, arcade button, Supabase claims page
Small restaurants and bakeries bin good food because donating small amounts is a hassle
- Hardware and sensors
Door Sign: an e-ink shop sign with four buttons that tells regulars the real hours today
The owner presses one of four buttons: Open, Delivery only, Open till 6, Closed. The e-ink sign at the door changes, and the same state goes to a public status page that regulars can check before they wade over. When hours change every day with the water, nobody has to post anything.
Build with ESP32, 4.2in e-ink, 4 buttons, Google Sheet or Supabase status page, QR sticker
Restaurants lose up to 80% of sales in a flood even when the building stays dry
- Hardware and sensors
Plate or Price: two big buttons on the cart where regulars vote with a press
Two arcade buttons sit by the cash box: 'same plate, +5 baht' and 'same price, smaller plate'. Each paying customer presses one, and an e-ink tag shows the running tally. By Friday the vendor knows what the regulars actually prefer, with no awkward conversation.
Build with ESP32, 2 arcade buttons, 1.54in e-ink, battery pack, Google Sheet log
Street food vendors absorb rising ingredient costs because they can't safely raise prices
- Hardware and sensors
Plate Scale: a kitchen scale that shows what each plate costs and what to list
A cook weighs the pork, basil and rice for one plate on a scale with three ingredient buttons. The screen adds up the cost, then shows the delivery price that still pays the shop after the 30% cut and the VAT on it. No notebook, no calculator, done at the wok.
Build with ESP32, HX711 load cell, 2.9in e-ink, 3 push buttons, price list in a JSON file
Small restaurants lose money on delivery apps and can't tell what price to list
- Hardware and sensors
Bag Stuffer: a receipt printer that adds a direct-order coupon to every delivery bag
A small thermal printer next to the pass prints a coupon slip with the customer's first name and a PromptPay QR for a direct order at 10% off. The price still beats the app after its 30% cut, so the shop earns more and the customer pays less. A cook presses one button when the rider picks up the bag.
Build with Raspberry Pi Zero 2 W, 58mm thermal printer, big arcade button, PromptPay QR generator, Google Sheet of direct orders
Small restaurants lose money on delivery apps and can't tell what price to list
Getting around
- Hardware and sensors
Rider Sticker: a QR on the vest that rings the rider's own phone
Each rider gets a waterproof sticker for the vest and a laminated card for nearby shops. Scanning it opens a one-tap call or a 'pick me up at 7:10' form that goes to that rider's phone, so a regular can reach the same rider without installing any ride app.
Build with QR generator, waterproof sticker print, Cloudflare Workers, SMS gateway
Motorcycle taxi riders with no app lose regulars who no longer walk to the win
- Hardware and sensors
Win Bell: a big button at a market stall or condo gate that buzzes the win
A shop or a market vendor with a heavy load presses a big button instead of walking to the win. An ESP32 sends a message to the win's group phone and a small speaker at the win beeps, and the first rider to tap 'go' is shown on a little screen at the button.
Build with ESP32, arcade button, small OLED, buzzer, Wi-Fi hotspot, SMS
Motorcycle taxi riders with no app lose regulars who no longer walk to the win
- Hardware and sensors
Pocket Route Card: a printed wallet card with your three buses, old and new numbers
The rider enters home, work and the places they go. The tool prints a credit-card-size card listing each bus with the new number, the old number people still say, the stops to board and where to get off, so riders without data don't need to ask the driver.
Build with Static site, BMTA open route data, printable PDF and thermal printer, laminate
- Hardware and sensors
Roll Logger: a clip-on sensor that scores every sidewalk you roll
An ESP32 with an IMU and GPS clips to the wheelchair frame. It logs bumps, tilt and stops as you ride and turns them into a roughness score per stretch of sidewalk, so the next rider sees which leg actually rolled well.
Build with ESP32, MPU6050 IMU, GPS module, LiPo battery, 3D-printed clip, map web page
Wheelchair users and their families can't tell which routes, venues and lifts in Bangkok are usable
- Hardware and sensors
Bike Tag: an NFC sticker on the seat links to the bike's pickup photos and rental terms
At pickup, the renter taps an NFC sticker on the bike and the walkaround photos, plate and agreed price are saved under that tag. At return, the shop and renter tap again to compare. Any later dispute starts from one shared record, not memory.
Build with NTAG213 NFC stickers, Web NFC, Supabase, PWA
Tourists on rented scooters get hit by fines or uninsured crashes they didn't expect
- Hardware and sensors
Policy Sticker: a printed helmet and bike tag that shows if cover is live and who to call
The driver photographs the insurance sticker once. The system prints a tough tag with a QR for the helmet and the bike. A bystander, paramedic or police officer scans it after a crash and sees whether compulsory cover is active, the insurer hotline, and the driver's emergency contact.
Build with QR sticker printer, Claude vision for insurance sticker, Cloudflare Worker, Next.js
Motorcycle taxi drivers face crashes and income swings with patchy insurance knowledge
- Hardware and sensors
Helmet Heat Buzzer: a clip-on sensor that buzzes at a heat index that halves your income
A small ESP32 with a temperature and humidity sensor clips to the vest or helmet. When the heat index crosses a dangerous level it buzzes and flashes, and a 20 minute rest timer starts. It also logs when the driver rested, so heat days show in the earnings data.
Build with ESP32, SHT31 sensor, buzzer, small LiPo, heat index formula
Motorcycle taxi drivers face crashes and income swings with patchy insurance knowledge
Tourism
- Hardware and sensors
Window Language Screen: a window screen that shows your sign in this month's top languages
A Raspberry Pi and an old monitor in the shop window cycle the price sign in the languages of the nationalities that most arrived this month. The page reads Ministry of Tourism and Sports arrival data and picks which two to show first. No printing, no guessing.
Build with Raspberry Pi 4, HDMI screen, Ministry of Tourism and Sports arrival stats, Claude, Chromium kiosk
Shops near Khao San see fewer tourists and have no cheap way to reach new ones
- Hardware and sensors
Door Counter: a camera that counts walk-bys and walk-ins to test your sign
A Raspberry Pi by the entrance counts people passing and people entering by the hour, on the device with no face storage. The AI writes a weekly note such as 'the new sign raised entries from 4 percent to 7 percent'.
Build with Raspberry Pi 4, camera module, on-device person detection (YOLO), SQLite, Claude
Shops near Khao San see fewer tourists and have no cheap way to reach new ones
- Hardware and sensors
Soi Depth Gauge: a cheap sensor at the street entrance that reports water depth
An ESP32 with an ultrasonic sensor sits above the entrance and measures water depth every minute. The hotel page shows 'water 18 cm: wheeled luggage not advised' in the guest's language, with a short AI-written note.
Build with ESP32, waterproof ultrasonic sensor, Claude, Cloudflare Worker
Small hotels can't tell arriving guests which routes and transfers work during floods
- Hardware and sensors
Last Mile Slip: the desk prints each guest a map, Thai driver line and boat number
A cheap thermal printer at the front desk prints one slip per arriving guest. It has a hand-drawn style map of the final 500 meters with flooded stretches crossed out, a Thai sentence to show a driver, and the hotel's phone number. Guests with a dead phone battery still have it.
Build with 58mm thermal printer, Raspberry Pi, Google Routes API, Claude, python-escpos
Small hotels can't tell arriving guests which routes and transfers work during floods
Small business
- Hardware and sensors
Foot Counter: a small camera that counts passers-by and how many stop at the stall
A cheap ESP32 camera on the stall pole counts people on the lane and those who stop within two meters, on the device, without saving faces. After a night the owner sees 'passed 840, stopped 62, bought 31' and can judge a 300 baht spot before paying for a month.
Build with ESP32-CAM, on-device people counter, OLED, Google Sheets
- Hardware and sensors
Last-Hour Stickers: a thermal printer that prints half-price signs at 9 pm
The owner taps a button on a small box with a receipt printer. It prints 'half price from 9 pm' tags and a sign with the item and quantity left, and counts how many tags were redeemed, so the extra sales cover part of the food that would be thrown out.
Build with Raspberry Pi, thermal printer, big button, Flask
- Hardware and sensors
Scan-and-Sheet: a 300-baht barcode scanner that logs sales to a sheet, not a POS
A USB barcode scanner on a small Pi or phone adds a row to a Google Sheet at each scan, with the price from a list. The owner scans each item as it goes into the bag and sees best-sellers by week for the cost of a scanner.
Build with USB barcode scanner, Raspberry Pi Zero 2, Google Sheets, product price list
- Hardware and sensors
Hold Clock: a countdown light at the counter that frees the slot when time runs out
When a room or chair is promised, the owner taps a button and a countdown starts on a small display or LED strip. It turns red at zero and the slot is posted as free, so there is no 9 PM guessing about whether the guest is coming.
Build with ESP32, OLED or LED strip, button, buzzer
- Hardware and sensors
Twin Tab Slip: a two-copy slip pad with item boxes, both sides keep one
A printed carbonless pad where the shop writes items and the amount and the customer signs. The customer keeps the second copy. A photo of the top copy is read into the shop's tab, so the 5,000 versus 9,500 baht problem has two matching papers.
Build with Carbonless pad design, printed QR, Claude vision, Sheets
Corner grocers and neighbors run credit on a handwritten tab that neither side can check
- Hardware and sensors
Tab Receipt Printer: a keypad and printer by the till that prints a running balance
The shop keys the neighbor's code and the amount. A small printer prints a slip with the item total and the new balance, so every sign-now-pay-later purchase leaves the customer with a receipt.
Build with ESP32 or Pi, 4x4 keypad, thermal printer, Google Sheets
Corner grocers and neighbors run credit on a handwritten tab that neither side can check
- Hardware and sensors
Slot Plates: numbered stall plates with a QR that pay the rent and prove the slot is yours
Each stall gets a printed plate or ground tag with a slot number and QR. A vendor scans it to pay rent through PromptPay and the page marks the slot as theirs for that day, so a standby seller can see it is taken and no one needs to shout.
Build with Printed plates, QR, PromptPay, Cloudflare Workers, Supabase
- Hardware and sensors
Foot Counter: a beam sensor at the gate that counts shoppers by the hour
Two cheap infrared sensors at the entrance count people in and out and draw a bar chart by hour. After two weeks the organizer and vendors can see which days and hours earn less than the stall rent and choose how to set prices and hours.
Build with ESP32, IR break-beam or PIR sensor pair, e-ink or phone page
- Hardware and sensors
Tag Printer: print a hang tag with price and a QR that plays the live clip
The shop takes a short video of a garment, and a small thermal printer prints a hang tag with the price, size and a QR. Scanning shows the stream clip and lets a buyer order, so walk-in traffic and online buyers meet on the same garment.
Build with Thermal label printer, Raspberry Pi, short-link service, QR generator
Pratunam and Bo Bae shop owners watch foot traffic vanish to livestream sales while rents stay high
- Hardware and sensors
Alley Stamp Card: one paper card that sends shoppers through ten shops
Ten neighboring shops print a shared stamp card with a QR. A shopper gets a stamp at each shop, and a full card wins a discount at the last one. The alley becomes a destination again without anyone needing the landlord or the city.
Build with Paper print, QR, Supabase stamp counter, rubber stamps or NFC stickers
Pratunam and Bo Bae shop owners watch foot traffic vanish to livestream sales while rents stay high
- Hardware and sensors
Shelf Scale: a load-cell tray that counts breakfast items by weight and logs sales
The maker puts a small ESP32 scale under the tray of 10 breakfast items at 20 baht each. Each time the weight drops by one item, a sale is logged with a timestamp, so the maker sees day-one sales and when they happened without asking the shop.
Build with ESP32, HX711 load cell, Wi-Fi, small web dashboard
Home cooks and makers who consign goods to shops get no sales report and sometimes no payment
- Hardware and sensors
Order Tags: a thermal-printed tag on each made-to-order piece shows what is owed and when
When production starts, the maker prints a small tag with the buyer's name, deposit paid, final due date and a QR to the progress photos. Tags go on the finished pieces on the shelf, so everyone sees which items are held and for how long.
Build with Thermal label printer, Next.js, QR code, Supabase
Makers of custom orders are stuck with finished goods when buyers stall or cancel after a deposit
- Hardware and sensors
Exit Check Tags: NFC stickers on every exit, staff tap each at opening time to prove it opens
Each exit door gets a 15 baht NFC sticker. Before opening, a staff member walks past, pushes each door and taps it with their phone, and the page logs the time. The owner gets a dated log that shows every exit was tested every day, and a missed tap shows in red.
Build with NTAG213 NFC stickers, Web NFC, Supabase, Next.js
Owners of small bars and restaurants can't easily self-check fire exits and materials
- Hardware and sensors
Blocked Exit Watch: a distance sensor that warns when stock piles up at an exit
A small ESP32 with a time-of-flight distance sensor faces the exit path. If something stays within 1.5 meters for more than 10 minutes during opening hours, a buzzer sounds at the bar and the owner gets a message with the time.
Build with ESP32, VL53L1X ToF sensor, buzzer, Wi-Fi webhook
Owners of small bars and restaurants can't easily self-check fire exits and materials
- Hardware and sensors
Shelf Time Capsule: a 400 baht ESP32 camera photographs your shelves every night
A small ESP32-CAM clipped above the counter takes one photo of the shelves at closing and uploads it with the date. If water comes, the owner already has dated before-photos, and the AI can compare them with after-photos to list what is gone.
Build with ESP32-CAM, Cloudflare R2, Claude vision, deep sleep timer
Flooded small shops have no simple record of lost stock, so bank and aid claims are hard
- Hardware and sensors
Cash Light: a lamp on the shelf that turns green, amber or red with days of cash left
The owner photographs slips and bills once a day. A small lamp shows how many days the cash covers against the bills coming due: green for 20+, amber for 7 to 20, red below 7. It makes the squeeze visible a week earlier than the bank balance does.
Build with ESP32, WS2812 ring, Claude vision for slips and bills, Google Sheets
Small shops with steady sales still run out of cash before month end
- Hardware and sensors
Debt Jar: a strip of LEDs that shrinks each time you pay
A glass jar lit by an LED strip shows the loan as a full column of light. Each time the vendor pays, a button press shortens it by that amount and the tiny screen shows true days left. Seeing the debt shrink every day makes it real, with no app and nothing to explain to the family.
Build with ESP32, WS2812 LED strip, OLED 0.96in, push button, jar
Street vendors borrow from informal lenders and can't see how fast the debt grows
Environment and air
- Hardware and sensors
Scrap Price Board: an e-ink sign at the collection point with today's price per kilo
A small e-ink panel shows today's buying price for paper, plastic, glass and metal from nearby buyers, updated each morning. Collectors see the number before they load the truck and decide whether to sell or hold, without opening any app.
Build with ESP32, 7.5 inch e-ink, WiFi, price scraper or manual entry sheet
Neighborhood waste collectors and shops can't see recyclable prices and lose income when they drop
- Hardware and sensors
Scale Slip: a hanging scale that weighs, prints a receipt and logs the sale
A cheap load-cell scale hung from a hook shows the weight, and a button chooses the material. It prints a slip with the kilos, the day's price and the amount, and keeps a log, so collectors have their own record to compare against the buyer's weighing.
Build with ESP32, HX711 load cell, thermal printer, buttons, Google Sheets
Neighborhood waste collectors and shops can't see recyclable prices and lose income when they drop
- Hardware and sensors
Bin Meter: an ultrasonic sensor on the bin lid that shows liters against the 20-liter line
A sensor on the lid measures how full the bin is and converts to liters. An LED turns amber near 20 liters and red above, so the owner sees in real time when the shop crosses the 120 baht per unit threshold.
Build with ESP32, HC-SR04 or VL53L1X sensor, e-ink or LED strip, battery
- Hardware and sensors
Two-Point Probe: PM2.5 at the AC vent and the room, a light shows where it leaks
An ESP32 with two PM2.5 sensors measures the air coming out of the AC vent and the air in the middle of the room. A small LED ring turns red when the vent air is dirtier than the room, which answers the 'does central AC pull in outside air' argument with numbers.
Build with ESP32, 2x PMS5003 sensors, LED ring, phone web page
- Hardware and sensors
Purifier Plug: a smart plug that runs your purifier only when the room needs it
An ESP32 plug watches indoor PM2.5 and switches the purifier on above 15 and off below 8, and refuses to run it with the door open. It logs hours and kWh, so people stop guessing whether it is worth the electricity.
Build with ESP32, relay module, PMS5003, Wi-Fi, simple web dashboard
Animals
- Hardware and sensors
Drop Box Scale: a community food bin that weighs donations and shows what is still needed
A bin at a cafe or pet shop sits on a scale. An e-ink screen shows 'for Wat cats: 12 kg in, 30 kg needed', and donors add a bag and watch the number move. The rescuer collects it on a known day, so the drop-off spot no longer depends on one person's schedule.
Build with ESP32, HX711 load cell, e-ink 4.2 inch, Google Sheets
Home animal rescuers and food donors can't find each other, and donors can't tell who is real
- Hardware and sensors
Soi Scoreboard: an e-ink board that shows the percent of dogs sterilized on this soi
A small e-ink board at the feeder's shop shows 'female dogs neutered on this soi: 55%, goal 80%'. Feeders tap an NFC tag with a phone to add or update a dog, and the board redraws the percent. A whole street can see how far it is from the number that makes the population fall.
Build with ESP32, 2.9in e-ink, NFC NTAG215, Supabase
Soi dog feeders and mobile neuter teams have no shared map of who is fed and sterilized
Jobs and work
- Hardware and sensors
Door Tap: an NFC sticker by the door that logs arrival and leaving
The housekeeper taps her phone on a sticker by the door when she arrives and leaves, no app to install. Both sides see the real hours, so an 8-to-6 job that ran to 8 PM shows up as overtime on the same page, and a no-show is on record.
Build with NFC sticker NTAG215, Cloudflare Workers, Next.js page, Thai and Burmese UI
- Hardware and sensors
Tap Slip: an NFC tap and a printed slip with hours and pay so far
Staff tap their phone or a keyring tag on a box by the till when they start and leave. A cheap thermal printer prints a slip with the day's hours, advances and pay owed, so the owner and the worker each hold the same record on paper, even if the worker quits tomorrow.
Build with ESP32, PN532 NFC reader, thermal receipt printer, Google Sheets API
Small cafe and shop owners can't keep daily staff who slack off or vanish, and have no pay record
- Hardware and sensors
Handoff Slip: a receipt printed at delivery that the client scans to confirm
At handoff of a physical job like the sculpture, the freelancer prints a small receipt with a QR from a pocket thermal printer. The client scans to confirm receipt with a photo and a timestamp, giving dated proof that the work was delivered.
Build with Bluetooth thermal printer, Next.js, QR code, timestamp and hash
Freelancers and informal workers finish the job, then chase unpaid pay with only chat logs as proof
- Hardware and sensors
Expiry Wall Calendar: a printed wall chart that marks each worker's start-renewal date
From scanned permits, the page prints an A3 wall calendar for the dorm or factory. Each worker's name is on the day they must start renewing, 60 days before expiry, with a color for how urgent it is. Nobody learns at the last minute that they must pay a broker to rush.
Build with Claude vision, Next.js, A3 PDF, thermal sticker printer for urgent flags
Myanmar workers pay brokers 11,000 to 18,500 baht for a permit extension that costs 6,000
Elderly care
- Hardware and sensors
Pill Box Light: a pill box that lights the right slot and texts if it stays shut
An ESP32 pill box lights the slot for the current time with an LED and a small buzzer. A reed switch notices when the lid was opened, and if it wasn't by an hour later, the family gets a text, so nobody guesses at the table at night.
Build with ESP32, WS2812 LEDs, reed switch, buzzer, SMS or Telegram
- Hardware and sensors
Night Button: a big bedside button that tells the carer on duty and counts the nights
The parent presses a big button when they need help. An ESP32 sends an alert to whichever sibling or neighbor is on the rota and logs each night event, so three bad nights in a row triggers a message to swap shifts instead of the same son going alone.
Build with ESP32, arcade button, Wi-Fi, Telegram or SMS alert
Working adults caring for sick or bedridden parents run out of sleep, leave days and money
- Hardware and sensors
Calm Box: one big button that plays a familiar voice or song when things get tense
The caregiver loads songs, a grandchild's voice message and a spoken reorientation like 'it's Tuesday, you're at home' onto a small box. When the patient gets agitated, anyone presses the big button and it plays, which gives the caregiver a few minutes of quiet.
Build with Raspberry Pi Zero, arcade button, small speaker, SD card, web upload page
- Hardware and sensors
Night Door Watch: a door sensor that wakes you only when he really walks out
A magnetic sensor on the bedroom and front doors plus a small bedside buzzer. It stays silent for toilet trips and rings only when the front door opens at night, so the caregiver can sleep instead of lying awake listening.
Build with ESP32, reed switch, buzzer, optional LINE notify, battery
- Hardware and sensors
Kettle Pulse: a smart plug that alerts family when the morning never starts
A power-metering plug on the kettle or rice cooker notices the usual morning use. If nothing has started by 10 AM, it sends a gentle call to the relative, then to a neighbor. The mother sees nothing, no camera, no button to remember.
Build with Shelly Plug or Tuya smart plug, Home Assistant or n8n, Twilio call
Older people living alone have no one to notice a missed day; relatives worry from afar
- Hardware and sensors
Hello Lamp: two lamps, one at mom's and one at yours, that glow when the other taps
Mom taps her lamp each morning and the son's lamp glows warm for an hour. He taps his and hers glows too. No tap by 10 AM turns his lamp amber and starts the kettle check, so the check-in feels like a hello and not surveillance.
Build with Two ESP32 with capacitive touch, WS2812 LEDs, MQTT, 3D-printed shells
Older people living alone have no one to notice a missed day; relatives worry from afar
- Hardware and sensors
Window Button: a LoRa button that works with no internet and lights up at the boat
An elderly person presses a big button by the window and a battery-powered LoRa radio sends 'meal wanted' to a box on the boat captain's phone. It works with the power and phone signal down. A light on the button turns green when the boat has seen the request.
Build with Heltec LoRa32 or ESP32 with SX1262, arcade button, LiPo battery, receiver on a phone via BLE
Elderly flood victims stuck upstairs depend on boats and baskets for cooked meals
Community groups
- Hardware and sensors
Deposit Slip Printer: a box that prints a receipt with the balance on every deposit
The treasurer keys in the member number and amount, or says them aloud. A thermal printer prints a slip with the new running balance and the date, so each member leaves with their own paper proof and the committee keeps a log.
Build with Raspberry Pi or ESP32, numeric keypad, thermal printer, Google Sheets
Volunteer-run community savings groups and housing co-ops lose track of member money
- Hardware and sensors
Study Tip Card: a pencil-case card that looks like study tips but hides a QR to real help
A printed card the size of a bookmark reads like exam tips on one side. A tiny QR on the other opens Quiet Mode. Print and share them at school fairs, tutoring centers and cafes, where a teenager can take one without anyone noticing.
Build with Claude, print-ready PDF, QR to Quiet Mode, small label printer
LGBTQ+ youth in Bangkok struggle to find safe, youth-focused help
- Hardware and sensors
Donation Box Screen: an e-ink panel at the donation box showing month income and spending
A Raspberry Pi with an e-ink screen sits next to the temple donation box and pulls from the ledger sheet. It shows donations this month, spending by category, and the latest receipts, updating after every PromptPay QR payment. Donors see where it goes while they stand there.
Build with Raspberry Pi Zero 2, e-ink 7.5in, Google Sheets API, PromptPay slip reading with Claude vision
- Hardware and sensors
Stop Card: a printed wallet card in Thai and your language with your case number
A volunteer or the person fills a short form on a phone. The system prints a folded wallet-sized card in Thai and the holder's language, such as 'I am registered with UNHCR, please call this number', with a trusted contact. It works when the phone is dead or taken.
Build with Claude translation, print-ready PDF, QR with offline text, label printer or home printer
Urban refugees in Bangkok lack safe multilingual information on services and legal risks
- Hardware and sensors
Info Box: a no-internet Raspberry Pi hotspot that serves vetted answers in your language
A small Raspberry Pi in a community center makes its own Wi-Fi with no internet and no logins. People join it and read or hear NGO-checked answers on clinics, schools and legal aid in Arabic, Urdu, Somali or Vietnamese. It stores no names and keeps no history.
Build with Raspberry Pi 4, hostapd Wi-Fi hotspot, captive portal, static site with TTS audio, Claude for translation
Urban refugees in Bangkok lack safe multilingual information on services and legal risks
- Hardware and sensors
Open Seat Lamp: press a cafe table lamp's button and nearby members get a join-me ping
A small Wi-Fi lamp with one big button sits on a cafe table. A solo regular presses it to say 'I'm here for the next hour, join me', the lamp glows, and members of the local group within walking distance get a short notification with the cafe name.
Build with ESP32, arcade button, NeoPixel ring, Supabase realtime, web push
Long-term residents and newcomers struggle to make friends beyond nightlife and meetups
- Hardware and sensors
Task Slips: a cafe thermal printer prints this week's NGO needs to take away
A cheap thermal printer sits beside the register at a cafe or pet shop. Press the button and it prints a slip such as 'PC builder, Saturday 10 am, Soi Dog feeding site, scan to claim'. The volunteer tears it off and scans the QR on it to say yes.
Build with 58mm thermal printer, Raspberry Pi, big arcade button, Supabase, QR code
People who want to volunteer with a skill can't find which small NGOs need it
- Hardware and sensors
Lane Tag: an NFC tag and e-ink board at the lane mouth showing what arrived
A volunteer boat or truck taps a phone on the tag at the lane entrance and picks what was dropped: water, kits, cooked meals, and how many. The e-ink board next to the tag shows what arrived and when, and what the lane still needs. Residents see it, and the next donor sees whether to come here or go to a lane with nothing.
Build with NFC NTAG215, ESP32 with SIM or Wi-Fi hotspot, 4.2in e-ink, solar bank, Supabase
Flood donations pile up in some places while other lanes say aid never arrived
Safety and scams
- Hardware and sensors
Safe Word Card: a wallet card with a family code word and the real children's number
A volunteer or grandchild sets a family code word and the three numbers the senior should call before sending money. The tool prints a laminated card with large type and a QR to a one-page explainer, so a fake 'your son is in trouble' call hits a wall.
Build with Static site, PDF template, thermal or normal printer, laminator
Older Bangkok residents get tricked online and don't know the laws or where to report
- Hardware and sensors
Offer Booth: a camera and printer kiosk that prints a verdict slip on a job offer
A job seeker holds the phone with the 'job' chat up to a Raspberry Pi camera. The kiosk reads the text and prints a receipt: 'pay-to-work, rising orders, withdrawal fee: do not pay', with the 1441 hotline. The slip is something to show a friend or family.
Build with Raspberry Pi, camera, thermal printer, Claude vision, Thai OCR
Job seekers lose savings to fake 'accept orders' part-time jobs that demand bigger top-ups
- Hardware and sensors
Till Mirror: a small screen at the stall that shows and says the note handed over
A Raspberry Pi camera over the cash tray reads the note a customer hands over and shows 'received: 1,000 baht' on a small screen facing the shopper, and says it aloud. Honest vendors get a way to prove they were not shorted, and shoppers see the count.
Build with Raspberry Pi, Pi camera, small LCD, speaker, Claude vision or a note classifier
Tourists at Chatuchak get shorted on change and can't prove what they handed over
- Hardware and sensors
Change Wheel: a printed cardboard slide chart that shows the change due
A pocket-size card with a rotating wheel: set the price, set the note you gave, and the window shows the exact change and which notes it should be, color-coded to the baht notes. It works with no phone and no signal, and a stall owner can see you are checking.
Build with Laser or paper printer, cardstock, brass fasteners, generator script for the wheel PDF
Tourists at Chatuchak get shorted on change and can't prove what they handed over
- Hardware and sensors
Booking Pad: a pocket pad of receipt slips with payee name, owner name and a verify QR
A tear-off pad of printed bilingual booking receipts for viewings. Blanks for owner name, payee name, unit, amount and date, with a QR to the name-match checker. The agent will not get a deposit without filling and signing a slip a tenant can show later.
Build with PDF layout, Claude for fill-in, print shop or home printer, QR code
Tenants can't tell if an agent really represents the owner before sending a deposit
- Hardware and sensors
Door Plate: an NFC plate on an honest tailor's door with fixed prices
A small plate by the shop door lists fixed prices, fabric per meter, fitting days and the final delivery date in five languages. Walk-by tourists tap or scan to see it and to book without pressure. The honest tailor now has a way to be seen on the same street as the scammers.
Build with NTAG NFC tag, laminated QR plate, Next.js, Claude translation
Visitors can't tell an honest tailor from a coordinated suit scam
- Hardware and sensors
Money Box: a speaker that says the amount only when the real bank alert arrives
A small box on the counter listens to the shop's bank alerts and says 'received 150 baht from Somchai' out loud. A fake slip on a customer's phone cannot make it speak, so the seller waits for the voice before handing over the bag. It works with the stall's own bank notifications, no new account.
Build with ESP32 with speaker, Android notification forwarder or bank webhook, Thai TTS clips
Market stalls and online sellers get fooled by sticker-swapped QR codes and fake slips
- Hardware and sensors
Stall Siren: one big button that flashes a light at every stall in the market
Each stall has a small lamp. When one seller hits the big red button after spotting a fake slip or a swapped QR, all neighbor lamps flash and a phone photo of the scammer goes to every stall. A market of 30 stalls protects itself in seconds.
Build with ESP32 with LoRa or Wi-Fi, LED lamp, arcade button, Telegram or LINE push for the photo
Market stalls and online sellers get fooled by sticker-swapped QR codes and fake slips
Learning and language
- Hardware and sensors
Leftover Scale: a bin scale that shows which menus the kids skip
A cheap load cell under the plate-scrape bin sends grams to an ESP32 with a small e-ink screen. The cook taps a button for today's menu, and a printed weekly card shows which dishes were thrown out most, so the teacher can swap them instead of guessing.
Build with ESP32, HX711 load cell, e-ink 2.9in, one button
- Hardware and sensors
Faculty Receipt Kiosk: press a faculty button, a dated receipt of jobs and pay prints
At a school fair or cram school, a box with big buttons per faculty prints a receipt: top three jobs, pay range and the date. The timestamp makes it clear the data is fresh, and the teen takes it home to show their parents.
Build with Raspberry Pi, arcade buttons, thermal printer, Job Outlook API
- Hardware and sensors
Learning Box: a Raspberry Pi hotspot that serves lessons with no data and no signal
A small box in a shop or community room makes its own WiFi and serves short Thai lessons, videos and quizzes. Kids connect between shifts and catch up for free, even when phone data has run out.
Build with Raspberry Pi 4, hostapd, Kiwix or custom PWA, Khan Academy Thai content, SD card
Khlong Toei kids who work mornings or have parents on long shifts can't keep up with school
- Hardware and sensors
Daily 5 Printer: a receipt printer at the library that prints five exam questions a day
A thermal printer at a community library or school prints five past-exam questions every morning with the answers on the back. Students pick the slip up, do it on the bus and check it later, no data plan or tutoring fee needed.
Build with Raspberry Pi, thermal printer, past exam corpus, cron job, QR to explanations
- Hardware and sensors
Tear-Off Tutor: print a neighborhood flyer with pull-off QR tabs for the board near you
The tutor says her subject, level and area. The tool lays out a printable flyer with 10 tear-off tabs, each with a QR to her page, ready for condo boards, cafes and campus walls near Kasetsart. The forum nobody read is replaced by a wall everyone walks past.
Build with Claude, print-ready PDF with tear-off layout, QR codes, Next.js
Freelance tutors can't find steady students and lose income when learners cancel or vanish
- Hardware and sensors
Pocket Phrase Card: type tomorrow's plan, print a foldable card of Thai with QR audio
The learner writes 'pharmacy for a cold tomorrow'. The tool prints a credit-card-sized foldable card with five key Thai phrases, romanization, likely replies and a QR that plays the audio. Hand it to the pharmacist if your words fail.
Build with Claude, thermal or label printer, QR code with TTS audio, print-ready PDF
Foreigners learning Thai stall at the alphabet and can't get conversation practice
- Hardware and sensors
Camp Gate Poster: a printed poster with audio QR that talks in Burmese or Khmer
A labor agent or contractor enters a camp location. The system finds the nearest schools with Google Places and prints a one-page poster in Burmese, Khmer and Thai. Scanning its QR plays a short spoken explanation that children can attend school, no chat needed.
Build with Google Places API, Claude, ElevenLabs or Google TTS, QR code, PDF printing
Migrant parents don't know their kids can enroll in Bangkok schools; kids lack Thai
Housing and condos
- Hardware and sensors
Gate Board: an e-ink board at the village gate showing this month's money in and out
An e-ink panel by the gate or mailbox shows how many houses have paid, the balance and the last five purchases. Anyone walking by can see it, and nobody has to go to the office to ask and get shouted down.
Build with ESP32, 7.5 inch e-ink, WiFi, Google Sheets feed
- Hardware and sensors
Door Statement: a printer that makes each house's paid-and-owed slip for its door
Once a month the volunteer prints a small slip per house: what it paid, what it owes and a QR for the books. The statement hangs on the doorknob, so the 20,000 to 30,000 baht fee has a record both sides can check.
Build with Raspberry Pi, thermal printer, Sheets, QR
- Hardware and sensors
Deal Card: a wallet card of 10 questions and 3 clauses to demand before you pay
A printed card with the ten questions to ask and the three sentences to ask the agent to write into the booking: refund if the loan fails, a dated handover and a written cancel route. A QR leads to the contract reader.
Build with Printed card, PDF template, QR, laminate
- Hardware and sensors
Site Cam: a cheap solar camera that snaps the site at 8 AM and 5 PM every day
An ESP32-CAM on a pole photographs the work site twice a day and posts the photos with timestamps to the owner. The owner sees when the crew showed up and how far the work really is, and a crew that vanishes leaves a clear record.
Build with ESP32-CAM, solar panel, LiPo battery, Wi-Fi or SIM, simple gallery page
- Hardware and sensors
Pet Tag: an NFC collar tag that holds chip number, vaccines and condo approval
An NFC tag on the collar opens the pet's passport when any phone taps it: chip number, vaccine dates, owner contact and a photo of the condo's written approval. It helps a lost pet get home and gives the owner proof ready if the juristic office asks.
Build with NTAG215 NFC, Next.js passport page, Claude (vaccine photo reader), QR backup
Pet owners can't find pet-friendly condos and don't know the new Bangkok pet registration rules
- Hardware and sensors
Lobby Answer Board: an e-ink screen by the mailboxes that answers the repeat questions
An e-ink panel in the lobby shows the 10 questions new owners ask most (parking, trash day, who fixes the pool pump) with the answer and phone number. A QR under it opens the full list, so nobody has to scroll a LINE group for a plumber's number.
Build with ESP32, e-ink 4.2in, Claude (to build answers from exported chat), QR code
New condo residents have only a LINE group to ask building questions
- Hardware and sensors
Own Bay Cam: a small camera on your own bay that logs who parks in it and when
A Raspberry Pi or ESP32-CAM aimed at the owner's own bay takes a photo when a car enters or leaves and logs the time. It gives an owner or tenant dated proof of who used the bay and for how long when a fee or fine is argued.
Build with ESP32-CAM or Raspberry Pi Zero, PIR sensor, Claude vision for Thai plates, Cloudflare R2
- Hardware and sensors
Wash or Wait: a two-probe thermometer that tells you if your aircon really needs washing
Two probes read the air temperature going in and coming out of the aircon. A clean unit drops 8 to 12 degrees, a clogged one drops far less. The screen says 'good, wait 6 more months' or 'wash it', which can save 800 baht a unit every 3 months.
Build with ESP32, two DS18B20 probes, OLED, 3D-printed holder
Residents can't find honest repair techs or know what an aircon wash should cost
- Hardware and sensors
Room Meter: a clip-on sensor that measures your own usage and proves your bill
A non-contact current clip on the room's breaker wire and an ESP32 log real kWh. The screen shows units used and what they cost at the building's 8 baht or at the 4.5 baht grid rate. When the building bills 182 units for a month the breaker was off, the tenant has the log.
Build with ESP32, SCT-013 current clip, ADS1115, OLED, Google Sheets log
Tenants pay double the grid rate for electricity and can't check building bills
- Hardware and sensors
Aircon Saver: an IR blaster that runs your aircon cheaper and shows baht saved
An ESP32 with an IR LED learns the aircon remote, then runs a night curve: 26 degrees, fan low, off after 3 hours. The screen shows units and baht saved against last week at 8 baht per unit. A hot-season bill of 3,200 baht gets visibly smaller.
Build with ESP32, IR LED and receiver, DHT22, OLED, Google Sheets
Tenants pay double the grid rate for electricity and can't check building bills
- Hardware and sensors
Decibel Puck: a sound meter that logs levels by minute and never records audio
An ESP32 puck on the wall measures loudness and logs the number and time, with no sound saved. Before 9 PM it shows green, amber near the house-rule limit. When the office says 'you were loud', the tenant has a minute-by-minute graph, and the neighbor who complains has the same graph.
Build with ESP32, I2S MEMS mic (INMP441), OLED or e-ink, Google Sheets log, 3D-printed case
Condo noise complaints turn into fines and fights with weak evidence on both sides
- Hardware and sensors
Meter Eye: a meter camera that logs readings and flags an empty room
A cheap camera on the meter photographs the dial every day and Claude vision reads it. The owner gets exact utility bills with proof, and a 10-day flat line while rent is late says the room is empty. Nobody needs to knock or guess.
Build with ESP32-CAM, 3D-printed clip, Claude vision, Google Sheets
Small landlords can't prove damage or recover rent when a tenant leaves or vanishes
Health
- Hardware and sensors
Refund Math Card: a pocket card that prints exactly what you are owed
Enter the course price, sessions used and how you paid. The tool prints a card with the baht amount owed under the pro-rata rule, the 7-day cancel right and the 15 days (45 for cards) deadline. Show it at the counter before anyone invents their own rule.
Build with Static site, PDF or thermal printer, rule logic, QR to OCPB online complaint
- Hardware and sensors
Quiet Receipt: a coworking-space button that prints a private list of next steps
A small thermal printer with one button sits in a coworking toilet or hostel corridor. Pressing it prints a receipt with three options: a crisis line that speaks English, a 24-hour hospital, and a licensed English-speaking counselor with a price. Nobody sees a screen, and the slip goes in a pocket.
Build with Raspberry Pi, thermal receipt printer, arcade button, curated resource list
Expats in distress can't quickly find English-speaking, licensed mental health help in Bangkok
- Hardware and sensors
Turn Pager: a vibrating wristband that signals it is the patient's turn
Waiting rooms call names out loud. A staff member types a queue number on a web page, and an ESP32 wristband worn by the patient vibrates and flashes, so a deaf patient is not skipped.
Build with ESP32, vibration motor, RGB LED, ESP-NOW or Wi-Fi, small web page
Deaf patients often face hospital visits without a sign language interpreter
- Hardware and sensors
Cook Card Printer: a hotel desk prints a Thai allergy card with pictures for the cook
At check-in, the guest picks their allergies on a tablet and the printer makes a waterproof card for the cook: the allergen in Thai with a picture, 'no peanut oil, no nam prik with peanuts, serious allergy'. It prints in two sizes, one for the wallet and one for the table.
Build with Next.js, Thai allergen glossary, thermal sticker printer, laminate
Travelers with severe food allergies can't reliably tell Thai cooks what they can't eat
- Hardware and sensors
Tooth Passport: an NFC wallet card that carries your X-rays and quotes to the next dentist
The patient photographs the X-ray and the quote and the page stores them under an NFC wallet card. A second dentist taps the card and sees the first dentist's findings, so 'healthy teeth' treated as 'needs work' becomes a visible mismatch. The card lives in the wallet, no app needed.
Build with NFC NTAG216 card, Next.js, Supabase storage, Claude vision for summaries
Foreigners can't judge if a Bangkok dentist's or clinic's plan and price are fair
Tools these ideas use: ESP32, Google Sheets, Raspberry Pi, arcade button, Next.js, thermal printer, Claude, Supabase, buzzer, QR code, Claude vision, HX711 load cell