Kindly Morrow
RP2040 Expansion Board with 3.5" Touch Screen
Plug a sensor into the breadboard, write twenty lines of MicroPython, and have a live touch-controlled graph on a 3.5-inch capacitive display before lunch. One board replaces a tangle of jumper wires, a separate display module, and a standalone breadboard. USB-C in, real pixels out.
The RP2040 dual-core Cortex-M0+ drives the display over SPI while the CST816 touch controller sits on I2C, both accessible without a separate driver board or shield stack. The integrated solderless breadboard accepts standard 2.54mm breakouts right next to the controller, so your sensor is three holes away from your firmware. Built for people who read datasheets and want a working prototype, not a cable management project.
Things to build with this
- BME280 environmental dashboard: plug the sensor into the breadboard over I2C, render scrolling temperature, humidity, and pressure graphs on the touch display using uplot or a custom framebuffer renderer, and fire the piezo buzzer when humidity crosses a user-set threshold tapped in on the touch screen
- Touch-controlled chord synth: divide the CST816 touch surface into a grid of tap zones, map each zone to a frequency played through the buzzer via PWM, and light the onboard RGB LEDs in a matching color per note so you can see and hear polyphonic input in real time
- Portable CSV data logger with on-device playback: wire a microSD SPI breakout into the breadboard, log timestamped sensor readings to a file on screen tap, then use the touch display as a file browser to select and graph any saved session directly on the 3.5-inch screen without a PC
Key Features
- RP2040: dual-core ARM Cortex-M0+ at up to 133MHz, compatible with MicroPython, CircuitPython, and the Pico C/C++ SDK
- 3.5-inch capacitive touch display: onboard SPI connection, no external driver board required
- CST816 touch controller (or compatible): communicates over I2C, community MicroPython drivers available and installable in minutes
- Integrated solderless breadboard: standard 2.54mm pitch, accepts breakout boards and passives without soldering
- Onboard RGB LEDs: addressable for status indicators, animations, or real-time visual feedback
- Piezo buzzer: wired and ready for alerts, tones, or RTTTL melody playback
- USB-C power input with 3.3V header pins for LiPo plus LDO or boost regulator integration
Frequently Asked Questions
Does MicroPython work with the touch screen out of the box?
Flash the standard Raspberry Pi Pico MicroPython UF2 and the RP2040 boots immediately. The display works with common SPI display libraries. The CST816 touch controller needs its own driver, which is available in community repos and takes about five minutes to wire into your project.
Is the breadboard area a real solderless breadboard or just exposed pads?
It is a physical solderless breadboard integrated into the board surface. Standard 2.54mm pitch components, breakout boards, and jumper wires all press in directly. No soldering required for prototyping.
How do you power this in a battery-backed project?
Primary input is USB-C. For battery integration, supply regulated 3.3V directly to the appropriate header pins. A LiPo with a small LDO or boost regulator is the standard approach and keeps the board running without the USB connection.
Why we stock this
Curated by Kindly Morrow. We test and vet every product before it hits the store. If we wouldn't use it in our own builds, we don't sell it.
Things to build with this
Fun projects to try once you get your hands on it.
Weather station that texts you
Hook up a temperature sensor and have it send you a Telegram message when it drops below freezing. 20 lines of MicroPython.
Garage door opener you control from bed
Wire a relay to your garage door motor and trigger it from your phone via Home Assistant. No cloud, no subscription.
Plant watering system that knows when to water
Soil moisture sensor + a small pump. Runs on a schedule or when the soil gets dry. Your plants stop dying.
Desk presence sensor for smart lighting
mmWave or PIR sensor detects when you sit down and turns on your desk lights. Turns them off when you leave. Zero effort after setup.
