Base Board CM4Duino - Lead expander for Raspberry Pi Compute Module 4 - compatible with Arduino - Waveshare 21738

Base Board CM4Duino is a pins expander from Waveshare designed for the Raspberry Pi Compute Module 4 Lite / eMMC computing module . The module has a special socket for connecting the CM4 module. It has been equipped with special connectors, thanks to which it extends the module 's capabilities by 40 GPIO pins, M.2 M KEY slot, USB2.0, CSI, HDMI connector, it also has a microSD card slot . The board is powered by 5 V, its dimensions are 73.58 x 53.34 mm.

Base Board CM4Duino - pins expander for Raspberry Pi Compute Module 4 - compatible with Arduino - Waveshare 21738.

Base Board CM4Duino - front view.

• Base Board CM4Duino - pins expander for Raspberry Pi Compute Module 4 - compatible with Arduino

The Raspberry Pi Compute Module 4 is not included in the kit - it must be purchased separately.

1. USB type C - power supply and system image upload interface; It can be powered by 5 V / 2 A, serves as an eMMC recording interface
2. USB 2.0 - interface for connecting peripherals
3. HDMI port - supports 4K 30 fps output
4. BOOT switch button - two-state: ON - the CM4 module starts up to the USB type C port; OFF - CM4 boots to eMMC or microSD card
5. CM4 connector - a socket for connecting the CM4 computing module
6. CAM interface - MIPI CSI camera interface
7. LED - LED for user programming
8. ADC ADS7830 chip - 8-bit ADC, I2C interface, 8-channel
9. Button - user programming button
10. GPIO - Arduino GPIO interface
11. Function switch - detailed information about its use can be found in the description of function pins
12. M.2 interface - M.2 M KEY slot, for connecting a communication module or NVME SSD
13. MicroSD slot - a slot for plugging in a microSD memory card to run Compute Module 4 Lite

The arrangement of elements on the board.

Base Board CM4Duino.

• Model: Base Board CM4Duino
• Type: expansion board, pins expander
• Purpose: compatible with Raspberry Pi Compute Module 4
• Connectors:
  • M.2 M KEY slot, for connecting a communication module or NVME SSD
  • GPIO pins compatible with Arduino
• USB interface:
  • 1x USB 2.0 type A
  • 1x USB type C for uploading the system image
• Camera connector: 1x MIPI CSI-2 (15-pin FPC 1mm connector)
• Video connector: 1x HDMI, supports 4K 30fps output
• External memory slot: microSD card slot for Compute Module 4 Lite variants (without eMMC memory)
• Supply voltage: 5V
• Tile sizes: 73.58 x 53.34 mm

1. Do not connect or disconnect any device other than USB and HDMI when it is turned on
2. Type-C interface can be used for power supply or as a USB interface for video recording (use BOOT switch to switch functions)
3. To ensure correct power supply to CM4, do not connect other devices while using the Burn-in Type-C interface.
4. During standard use of CM4, 5V / 2A power supply is necessary. Otherwise, problems such as automatic shutdown, frequency reduction and others may occur.
5. The USB 2.0 interface is closed by default, if you want to open it you need to add the command: dtoverlay = dwc2, dr_mode = host in config.txt

The board also has a microSD memory card slot.

• The website of the manufacturer: Waveshare 21738
• Product Wiki page
• Layout diagram
• 3D model