The RP2350 has 26 GPIO pins, 2 I2C buses, 2 SPI buses, 2 UART ports, 3 ADC channels, 2 I2S interfaces, 2 programmable state machines (PIO), and native USB — plus 520KB of SRAM and 4MB of flash. Every peripheral below is a MicroPython import away.
- BME280 — temp / humidity / pressure
- MPU6050 — accelerometer + gyro
- MAX30102 — heart rate / SpO2
- SSD1306 — 128×64 OLED display
- VL53L0X — laser distance (ToF)
- DS3231 — real-time clock
- ADS1115 — 4-ch 16-bit ADC
- ENS160 — VOC + CO₂ air quality
- HMC5883L — compass
- SD card reader — local data logging
- ILI9341 / ST7789 — color TFT display
- RFID RC522 — card tap / access
- LoRa SX1278 — long-range radio
- W5500 — wired Ethernet
- MCP4921 — 12-bit DAC output
- NRF24L01 — 2.4 GHz radio link
- NEO-6M / NEO-8M — GPS position
- SIM800L / SIM7600 — SMS + 4G data
- HC-05 / HC-06 — Bluetooth serial
- RS485 / Modbus — industrial sensors
- Pi 5 host — command + data bridge
- NMEA weather station sensors
- Electret microphone — audio level
- Potentiometer — manual control
- LDR — ambient light reading
- Soil moisture probe — plant alert
- MQ-2 / MQ-7 / MQ-135 — gas sensors
- ACS712 — current sensor
- Thermistor — precision temp
- MAX98357A — 3W Class D amp (speaker out)
- PCM5102 — hi-fi stereo DAC
- INMP441 — MEMS microphone in
- MAX9814 — auto-gain mic amp
- WM8960 — stereo codec in/out
- WS2812 NeoPixel strips — any length
- Stepper motor — precise timing
- Quadrature encoder — position tracking
- Custom serial protocol — any baud
- DCC — model train control
- I2S bit-bang — custom audio
- PS/2 keyboard / mouse decode
- Keyboard — macro pad / stream deck
- Mouse / joystick
- MIDI controller — DAW integration
- Gamepad — retro controller
- CDC serial — Pi 5 data bridge
- Mass storage — appear as USB drive
- Relay module — mains switching
- Servo motor — pan/tilt/mechanical
- A4988 stepper driver — CNC axis
- IR TX/RX — remote control signals
- HC-SR04 ultrasonic — distance
- PIR — passive motion detect
- Piezo buzzer — tones + alerts
You don't need to buy a sensor kit. Old phones and computers are full of precision hardware that was engineered to last — motors, cameras, speakers, batteries, gyroscopes, displays. Strip them, wire them to a Pico 2, give them a second life doing something useful.
- Vibration motorERM tactile motor → haptic alerts wired to Pico GPIO + transistor
- Camera moduleOV2640 / OV7670 → motion detection or time-lapse via Pico PIO + DVP interface
- OLED / LCD screenSPI or I2C display → mini status ticker, temp readout, clock face
- Electret micTiny capsule → Pico ADC audio level meter or voice-trigger circuit
- Small speaker8Ω 0.5W → pair with MAX98357A for I2S audio out on the cheap
- Li-Po battery3.7V cell + TP4056 charging board → fully off-grid / solar Pico node
- Accelerometer / gyroMPU6050-era chip → tilt sensing, shake detection, orientation data over I2C
- GPS chipIf present, desolder and use raw UART NMEA stream → location-aware sensors
- NFC antennaPair with PN532 breakout → tap-to-identify, card presence detect
- Proximity sensorIR photodiode pair → touchless button, object present / absent detection
- Fingerprint sensorFPC1020-type → biometric trigger for door lock or boot gate via UART
- WiFi antenna wireExtend range on Pico W by soldering to U.FL pad with salvaged antenna
- CPU cooling fan3-pin / 4-pin PC fan → PWM-controlled enclosure ventilation, Pico reads temp + drives fan
- ATX power supplyStable 12V / 5V / 3.3V rails → bench supply for any Pico project, no batteries needed
- Keyboard matrixLaptop membrane + controller → custom macro pad via Pico USB HID emulation
- TouchpadI2C trackpad chip → touch-drag control surface for Pico W web dashboards
- DVD stepper motorPrecision lead screw actuator → camera slider, pen plotter, mini linear stage
- Optical encoderCD/DVD sled encoder strip → sub-mm position feedback via Pico PIO quadrature decode
- HDD rare earth magnetsIncredibly strong neodymiums → magnetic field experiments, reed switch triggering
- HDD plattersMirror-finish discs → persistence-of-vision display: spin + laser + Pico PIO timing
- CD drive laser650nm diode → laser pointer, basic LIDAR distance experiments (low power)
- Laptop battery cells18650 cells inside dead packs → high-capacity power bank for extended field nodes
- Webcam (USB)With RP2350 USB host mode → image capture, barcode scan, basic vision input
- Internal mic / speakerSalvaged laptop audio → input + output for Pico I2S audio pipeline, no BOM cost
temp-sensor
Reads the RP2350 onboard temperature sensor. Streams JSON over USB serial every 5 seconds. LED heartbeat on every reading. No extra hardware — just the bare board and a USB cable. Live on the Pi 5 closet node.
View project → project / 02audio-speaker
Receives a WAV file over USB serial, plays it via I2S to a MAX98357A amplifier. Paired with the Morning Chaos Briefing — hears the 6 AM dispatch call out loud. Salvageable: use a phone speaker instead of buying one.
View project → project / 03fan-controller
Salvaged PC fan wired to Pico PWM. Reads temp from BME280 via I2C, drives fan speed proportionally. Logs RPM tach pulses via GPIO interrupt. Mount it in any enclosure that gets hot.
Fork and build it → project / 04haptic-notifier
Phone vibration motor driven by Pico GPIO + NPN transistor. Pi 5 sends events over serial (Discord DM, alerter trigger, dispatch ping). Pico buzzes once for info, three times for urgent.
Fork and build it → project / 05rfid-access
RC522 RFID reader on SPI. Logs card UIDs over serial to Pi 5 → ShaneBrain Weaviate SecurityLog. One known card = open relay, unknown card = Discord alert. Salvage: use an old phone NFC coil as antenna extension.
Fork and build it → project / 06neopixel-ring
WS2812 LED ring driven by Pico PIO state machine — zero CPU overhead. Pi 5 sends system health JSON over serial. Green = all good, amber = warning, red + chase = alert. Mount anywhere visible.
Fork and build it → project / 07soil-monitor
Capacitive soil moisture probe on Pico ADC. Posts readings every 30 min over serial to Pi 5 → ShaneBrain daily note. Add a relay to auto-water when dry. Good first-build for anyone starting with ADC.
Fork and build it → project / 08macro-pad
Salvaged laptop keyboard matrix decoded by Pico, presented to the host as USB HID keyboard. Map any key to any macro, script, or Discord command. No drivers. Plug in, it works. Dead laptops reborn.
Fork and build it →↳ Angel Cloud — public wellness platform
↳ Pulsar Sentinel — post-quantum security
↳ pico-nerve-endings
Every project here is self-contained and forkable. Clone one folder, read its README, flash the firmware, run the host script. No ecosystem knowledge required.
Built with Claude (Anthropic) on a Raspberry Pi 5 in a closet in Alabama.
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The Left-Behind User