I wanted to create a board that offered as many different connections as possible. I like to create small robot models and it was really important to offer connections for H-bridges, stepper motors and a whole collection of servos. Sensors are either analogue or digital, and most of them require some sort of power connection.
As a result of all of these decisions, I’ve decided to make the connections based on the pattern set by servo connectors. On these, the centre connection is the positive (+V or Vcc) power supply, one connection is Ground (Gnd) and the final connection is the control signal. On this board, all of the connections face towards the Raspberry Pi Pico.
The pin allocations are based on those given for Microblocks running on the Raspberry Pi Pico at: https://wiki.microblocks.fun/boards/special_pins
| External Pins (Some pins can suit a variety of functions). | Used For: |
| Pins 0-22 | Digital I/O only (2,3,6,7,8,9 in use for on-board functions) |
| Pins 0,1 | Serial UART : Pin 0 – TX Pin 1 – RX |
| Pins 4,5 | I2C : Pin 4 – SDA Pin 5 – SCL |
| Pin 10,11 | Suitable for an ultrasonic sensor or general I/O use. |
| Pins 12-19 | are suitable for servos and have 5v Power Available. |
| Pins 14-17 | are also available on the back for connection to a dual H-Bridge for DC motors or Bipolar/Unipolar Stepper Motor driver. A 5V Power Supply is available. |
| Pins 16-19 | SPI Pin 16 – SPI MISO Pin 17 – SPI SS Pin 18 – SPI Clock Pin 19 – SPI MOSI |
| Pins 20-22 | Digital I/O with 3.3v Power Supply |
| Pins 26-28 | Analog or digital inputs with 3.3v Power Supply |
| Internal Pins | |
| Pin 23 | (digital output) turn on for better voltage regulation (uses a bit more power) |
| Pin 24 | (digital input) detects USB connected |
| Pin 25 | (digital output) user LED |
| Pin 29 | (analog input) temperature sensor |
| On-board components | |
| Pin 2 and Pin 3 | On-board LEDs |
| Pin 6,7,8,9 | Tactile Switches |
| Pin 4,5 | I2C OLED Display connected to Pin 4 – SDA Pin 5 – SCL and running from 3.3v |
rPi Kitchen 