UDOO KEY P1, P2 and P5 header


The Pico-compatible part of the UDOO KEY is built upon a Raspberry Pi RP2040 microcontroller, dual Arm Cortex-M0+, with a QSPI 8MB Flash, a 133MHz clock and 264KB of on-chip SRAM. The RP2040 microcontroller is a chip from Raspberry Pi Foundation that integrates two Arm Cortex-M0+ CPUs that can be run up to 133MHz, featuring 264kB of on-chip SRAM and up to 16MB of off-chip Flash memory. This microcontroller can be used for machine learning, motor control, audio and so on. The UDOO KEY is 100% compatible with Raspberry Pi Pico both hardware and software-wise. This means that each and any expansion hardware as well as each and any software built for Raspberry Pi Pico will work out of the box on UDOO KEY. For further information on RP2040, please refer to the dedicated page on raspberrypi.com.

P1 and P2 connectors of the Pico part can be used to connect external peripherals to the RP2040. Two 20-pin headers or castellated holes must be soldered on P1 and P2 in a proper manner to use them . The following tables summarize the possibilities offered by P1 and P2 connectors.

P1

Pin number Schematic pin name SPI UART interface I²C PWM SIO/PIO
1 N.C. - - - - -
2 N.C. - - - - -
3 GND - - - - -
4 RPI_SDA SPI0_SCK UART0_CTS I2C1_SDA PWM1_A SIO/PIO0/PIO1
5 RPI_SCL SPI0_TX UART0_RTS I2C1_SCL PWM1_B SIO/PIO0/PIO1
6 GP4 SPI0_RX UART1_TX I2C0_SDA PWM2_A SIO/PIO0/PIO1
7 GP5 SPI0_CSn UART1_RX I2C0_SCL PWM2_B SIO/PIO0/PIO1
8 GND - - - - -
9 GP6 SPI0_SCK UART1_CTS I2C1_SDA PWM3_A SIO/PIO0/PIO1
10 GP7 SPI0_TX UART1_RTS I2C1_SCL PWM3_B SIO/PIO0/PIO1
11 GP8 SPI1_RX UART1_TX I2C0_SDA PWM4_A SIO/PIO0/PIO1
12 GP9 SPI1_CSn UART1_RX I2C0_SCL PWM4_B SIO/PIO0/PIO1
13 GND - - - - -
14 GP10 SPI1_SCK UART1_CTS I2C1_SDA PWM5_A SIO/PIO0/PIO1
15 GP11 SPI1_TX UART1_RTS I2C1_SCL PWM5_B SIO/PIO0/PIO1
16 GP12 SPI1_RX UART0_TX I2C0_SDA PWM6_A SIO/PIO0/PIO1
17 GP13 SPI1_CSn UART0_RX I2C0_SCL PWM6_B SIO/PIO0/PIO1
18 GND - - - - -
19 GP14 SPI1_SCK UART0_CTS I2C1_SDA PWM7_A SIO/PIO0/PIO1
20 GP15 SPI1_TX UART0_RTS I2C1_SCL PWM7_B SIO/PIO0/PIO1

Pin number 1 and 2 are not connected since are used for MCUs communication.

P2

Pin number Schematic pin name SPI UART interface I²C PWM SIO/PIO
1 GP16 SPI0_RX UART0_TX I2C0_SDA PWM0_A SIO/PIO0/PIO1
2 GP17 SPI0_CSn UART0_RX I2C0_SCL PWM0_B SIO/PIO0/PIO1
3 GND - - - - -
4 GP18 SPI0_SCK UART0_CTS I2C1_SDA PWM1_A SIO/PIO0/PIO1
5 GP19 SPI0_TX UART0_RTS I2C1_SCL PWM1_B SIO/PIO0/PIO1
6 GP20 SPI0_RX UART1_TX I2C0_SDA PWM2_A SIO/PIO0/PIO1
7 GP21 SPI0_CSn UART1_RX I2C0_SCL PWM2_B SIO/PIO0/PIO1
8 GND - - - - -
9 GP22 SPI0_SCK UART1_CTS I2C1_SDA PWM3_A SIO/PIO0/PIO1
10 RPI_RESET - - - - -
11 GP26 SPI1_SCK UART1_CTS I2C1_SDA PWM5_A SIO/PIO0/PIO1
12 GP27 SPI1_TX UART1_RTS I2C1_SCL PWM5_B SIO/PIO0/PIO1
13 GND - - - - -
14 GP28 SPI1_RX UART0_TX I2C0_SDA PWM6_A SIO/PIO0/PIO1
15 ADC_VREF - - - - -
16 3V3 - - - - -
17 N.C. - - - - -
18 GND - - - - -
19 VSYS - - - - -
20 VBUS - - - - -

Pin number:

  • 10 is reserved for RP2040 reset by ESP32
  • 16 provide 3.3V DC (315mA) in output
  • 17 is not connected
  • 19 provide 5V DC (500mA) filtered from USB Type-C connector (CN1)
  • 20 provide 5V DC (500mA) raw from USB Type-C connector (CN1)

P5

The Serial Wire Debug interface is available on the 1x3 poles connector P5. This header allows you to program and debug the RP2040 microcontroller externally.
The following table shows the pin configuration.

Pin number Function
1 SWCLK
2 GND
3 SWDIO
This page was last updated on Wednesday, July 27, 2022 at 8:00 AM.