Full Specifications

Below the full technical specifications

ESP32 RP2040
Memory 8 MB PSRAM 264 KB PSRAM
Flash storage 16 MB internal SPI flash 64M-bit external QSPI flash
Connectivity Wi-Fi 802.11 b/g/n (802.11n up to 150 Mbps), Bluetooth v4.2 BR/EDR and BLE specification -
RF power WiFi: 20 dBm, BT:13.7 dBM -
Modulation type GFSK, OFDM -
Frequency bands 2400 ÷ 2483.5 MHz -
Bandwidth BT / BLE: 1 MHz (79 channels) / 2 MHz (40 channels) -
Peripherals UART, I²C, SPI on UEXT connector, blue and yellow LEDS, SWD lines to RP2040 UART, SPI, I²C on P1 and P2 , green LED
Sensors SPK0838HT4H-1 Microphone, shared ICM-20948 IMU Shared ICM-20948 IMU

Operating temperature: 0°C ÷ +60°C
Power supply: +5VDC
Dimensions: 130 x 40 x 10.9 mm


In addition to this guide, several ones are available online:

Board versions

The UDOO KEY is available in two versions: UDOO KEY Basic and UDOO KEY Pro.

The UDOO KEY Basic mounts no sensors, it is therefore perfect for those who want full control of their project, as it allows expansion with modules of developer’s choice.
The UDOO KEY Pro mounts two powerful sensors: a 9-axis IMU and a digital microphone.

  • The 9-axis IMU motion sensor, an ICM-20948, combines an accelerometer, a magnetometer and a gyroscope in a single module to streamline a wide array of projects, from robotics and RC cars up to smart bikes and automation. It is connected to the ESP32 via I2C bus. You can decide whether to access the I2C bus via ESP32 or RP2040 through the jumper switch.
  • The omnidirectional digital microphone, a SPK0838HT4H, is designed for AI-powered sound & voice recognition as well as audio control. It is connected to the ESP32 via I2S bus.

The following table and picture summarize the differences between the UDOO KEY Basic and the UDOO KEY Pro.

Sensors on chip temperature sensor (RP2040) on chip temperature sensor (RP2040)

9-AXIS IMU motion sensors

omnidirectional digital microphone

Notice that, only for kickstarters, the IMU sensor has been changed and is currently installed the model MPU-6500, a 6-axis motion tracking sensor.

Board headers

The UDOO KEY features four useful pinout header.

The pin header connector P3 on the top of the board is compliant with the UEXT specification and is accessible from the ESP32. It exposes the I2C, UART, and SPI interfaces.

UDOO KEY P3 header

The two headers on the bottom of the board, P1 and P2, are 100% compatible with Raspberry Pi Pico, both hardware and software-wise – except for two GPIO pins used for UART mapping, namely GP0 and GP1, to ensure the communication between the ESP32 and the RP2040. This means that each and any expansion hardware as well as software built for Raspberry Pi Pico will work out of the box on the UDOO KEY.
Finally, on P5 header are connected SWD lines (SWDCLK, GND and SWDIO) to easly program the RP2040, as for the Raspberry Pi Pico.

UDOO KEY P1, P2 and P5 header

Power source

The UDOO KEY can be powered by an external power supply of +5V DC (max 2.5A) via USB Type-C connector (C1).
The board is also provided with a 2.5A 32V DC fuse to protect itself from overcurrent injection.
The USB Type-C connector powers up both the ESP32-WROVER-E module and the RP2040, and all peripherals connected on.

The UDOO KEY can go into deep sleep, reducing the power consumption to a minimum. In this state it only awakes if triggered by a specific event, thus extending battery life up to several years.

This page was last updated on Wednesday, July 27, 2022 at 8:00 AM.