Multi Camera Adapter Module for Raspberry Pi Published by on

Before We Start Standard RPi boards (not Compute Module) accept a single MIPI camera, but Arducam offers solutions that take multiple. This blog is the release of the first revision that supports 5MP V1.3 camera multiplexing in 2015.



Later, we’ve released a newer adapter to add 8MP support, and then a Stereo Camera HAT to disguise multiple cameras working simultaneously as a single connection acceptable to the Pi. Therefore, this product is officially end-of-life.











Introduction

This Raspberry Pi multi-camera adapter module is designed for connecting more than one camera to a single CSI camera port on the Raspberry Pi board. Each adapter board can connect up to 4 cameras and the user can stack up maxim 4 adapter boards, which means up to 16 cameras on a single Raspberry Pi board.

Please note that this Raspberry Pi multi-camera adapter board is a nascent product which may have some stability issues and limitations because of the cable’s signal integrity and RPi’s closed source video core libraries, so use it at your own risk.

Application

IoT cameras

Robot cameras

Wildlife cameras

3D scanner

Features

Accommodate 4 Raspberry Pi cameras on a multi-camera adapter board

Stackable and maxim cascade 4 adapter boards

3 GPIOs required for multiplexing on one adapter board, 5 GPIOs for two adapter board, 9 GPIOs for four adapter board

All camera ports are FFC (flexible flat cable) connectors

DIP switches for easy stack up configuration

Support Raspberry Pi A/B/B+ and Pi 2.

Pin Configuration

DIP switches are used here for easy stack up configuration. When only one multi-camera adapter board is used, the switches 1and 5 should be switched to ON position. If two multi-camera adapter boards are used, the downside board should be switched 1 and 5 to ON and upside board should be switched 2 and 6 to ON position, and if 3 or 4 multi-camera adapter boards are used together each board layer should be configured as the Table 1 shown.

Table 1 Pin Configuration

Operation

For proper operation, only one camera should be enabled at a time. In case of only one multi-camera adapter board is used, driving Pin12 HIGH and driving Pin11, Pin7 to LOW to enable camera A on the adapter board. Enable camera B, C, and D, please refer the Table 2 for camera selection configuration. To disable all cameras on one adapter board, Enable 1 and Enable 2 signals should be toggled HIGH. Care should be taken that it is not allowed to drive the Enable 1 and Enable 2 LOW at the same time. When connecting more than two multi-camera adapter boards, only one of the cameras can be enabled by enabling the desired camera on one adapter board and disable all the cameras on the rest of adapter boards.

Table 2 Camera Selection Configuration

Camera Selection Configuration Selection Enable 1 Enable 2 A 0 0 1 B 1 0 1 C 0 1 0 D 1 1 0 No Camera X 1 1 Error X 0 0

(X: don’t care)

Software Demonstration

Before using it, required dependency python-rpi.gpio have to be installed with

sudo apt-get install python-rpi.gpio

the command from the Terminal. Then run the following code for the quick demo.

import RPi.GPIO as gp import os gp.setwarnings(False) gp.setmode(gp.BOARD) gp.setup(7, gp.OUT) gp.setup(11, gp.OUT) gp.setup(12, gp.OUT) gp.setup(15, gp.OUT) gp.setup(16, gp.OUT) gp.setup(21, gp.OUT) gp.setup(22, gp.OUT) gp.output(11, True) gp.output(12, True) gp.output(15, True) gp.output(16, True) gp.output(21, True) gp.output(22, True) def main(): gp.output(7, False) gp.output(11, False) gp.output(12, True) capture(1) gp.output(7, True) gp.output(11, False) gp.output(12, True) capture(2) gp.output(7, False) gp.output(11, True) gp.output(12, False) capture(3) gp.output(7, True) gp.output(11, True) gp.output(12, False) capture(4) def capture(cam): cmd = "raspistill -o capture_%d.jpg" % cam os.system(cmd) if __name__ == "__main__": main() gp.output(7, False) gp.output(11, False) gp.output(12, True)

As normal camera operations, users can still use raspistill or raspivid command to take photos or videos. By control the GPIOs according to Table 1 and Table 2 configuration, users can take photos or videos by switching between different cameras. Have fun!