PicoPad is a Czech game console and DIY kit from Pájeníčko built around the Raspberry Pi Pico (RP2040; the Wifi version uses the Pico W, and newer units also the Pico 2 with RP2350). On its top edge it has the EXT external connector – a 2 × 6 pin socket for your own extensions: 6 GPIO with UART, I2C and three analog inputs, 3.3 V and battery power.
The remaining Pico pins are taken by the display, buttons, microSD card and audio – see the overview in the table below.
Specifications
- Raspberry Pi Pico / Pico W / Pico 2: RP2040 (2× Cortex-M0+ 133 MHz) or RP2350
- EXT connector: 2 × 6 socket, 6 GPIO (GP0, GP1, GP14, GP26–28)
- UART0 (GP0/GP1), I2C0 (GP0/GP1) or I2C1 (GP14/GP27), ADC0–2 (GP26–28)
- 3.3 V and VSYS power (from the battery, after the power switch), ADC_VREF and AGND for more accurate measurements
- 2″ 320 × 240 ST7789 display, 8 buttons, microSD card, speaker, Li-Ion cell with charger
The diagram shows a top view of the console’s top edge at the right end, where the socket opens outward: on the left is the front side with the display (even pins), on the right the back cover (odd pins); pins 1 and 2 are closest to the right corner. It applies to the PicoPad 1.0, the PicoPad Wifi and units fitted with the Pico 2.
The PicoPad Pro has the same signals, but the connector is rotated by 180° – expansion boards plug into it the other way around. The Pro also adds the PICOBUS bus and an I2C connector (μŠup/Qwiic).
The names D0–D5 and A0–A2 come from CircuitPython (board.D0 …); board.I2C() and board.UART() use GP0 and GP1.
Pinout and pin table
Hover over a pin in the diagram or a table row; use the filter to highlight a bus. You can download the pinout as PNG or SVG.
| Pin | Name | CircuitPython | Direction | UART | I2C | SPI | PWM | ADC | Note |
|---|---|---|---|---|---|---|---|---|---|
| EXT (J2) 1 | GND | – | |||||||
| EXT (J2) 2 | GND | – | |||||||
| EXT (J2) 3 | 3V3 | output | 3.3 V output from the Pico – shared by the display and SD card | ||||||
| EXT (J2) 4 | VSYS | input/output | Silkscreened "VBAT" on the protoboard, BAT in the schematic: the cell via the switch and a Schottky diode to the Pico's VSYS. On battery about 0.3 V below the cell, with USB connected about 4.7 V even with the switch off; off without USB = 0 V. | ||||||
| EXT (J2) 5 | GP28 | A2 | input/output | UART0 TX | I2C0 SDA | SPI1 RX | PWM6 A | ADC2 | |
| EXT (J2) 6 | ADC_VREF | input/output | Filtered ADC reference on the Pico – do not use as a power supply. | ||||||
| EXT (J2) 7 | GP27 | A1 | input/output | UART1 RTS | I2C1 SCL | SPI1 TX | PWM5 B | ADC1 | ADC1, I2C1 SCL (SCL_ALT v CircuitPythonu) |
| EXT (J2) 8 | AGND | – | Analog ground for the ADC (GP26–28) | ||||||
| EXT (J2) 9 | GP0 | D3 | input/output | UART0 TX | I2C0 SDA | SPI0 RX | PWM0 A | UART0 TX (default PicoLibSDK console); in CircuitPython both TX and SDA (board.UART, board.I2C). PWM shares its output with the display backlight (GP16). | |
| EXT (J2) 10 | GP26 | A0 | input/output | UART1 CTS | I2C1 SDA | SPI1 SCK | PWM5 A | ADC0 | ADC0, I2C1 SDA. Shares a PWM slice with GP27. |
| EXT (J2) 11 | GP1 | D2 | input/output | UART0 RX | I2C0 SCL | SPI0 CSn | PWM0 B | UART0 RX, v CircuitPythonu RX i SCL. | |
| EXT (J2) 12 | GP14 | D1 | input/output | UART0 CTS | I2C1 SDA | SPI1 SCK | PWM7 A | I2C1 SDA (CircuitPython SDA_ALT). Shares a PWM slice with audio (GP15). |
Pins used on the board
These chip pins are used by parts on the board and are not broken out:
| Pin | Function on the board |
|---|---|
| GP2–5 | Buttons right, left, up, down (active low, internal pull-up) |
| GP6–9 | Buttons B, A, Y, X (active low) |
| GP10–13 | microSD card on SPI1 – SCK, MOSI, MISO, CS (blue "SD" LED on CS) |
| GP15 | Sound – PWM to a transistor and speaker |
| GP16 | Display backlight |
| GP17–21 | ST7789 320 × 240 display on SPI0 – DC, SCK, MOSI, RES, CS |
| GP22 | Yellow USR LED (lit at logic 0) |
| GP29 | Battery voltage (ADC3, VSYS ÷ 3 on the Pico); shared with the Wi-Fi chip on the Pico W |
| GP23–25 | Inside the Pico (on the Pico W, Wi-Fi chip lines) |
What to watch out for
- GPIO are not 5V tolerant.
- Pin 4 is not the cell directly: on battery it is about 0.3 V lower, with USB connected about 4.7 V.
- 3.3 V is shared by the display, backlight and SD card – keep the external load small.
- ADC_VREF is the Pico’s ADC reference – don’t load it.
- On the PicoPad Pro the connector is rotated by 180°.
PicoPad on chiptron.eu/
Projects and guides on chiptron.eu/:
- Picogame – a game engine for CircuitPython that also runs on the PicoPad
More pinouts
See all pinouts on the Pinouts page.