PICO-IMX8M TEVS Camera Usage Guide
🚀 Introduction
This article guides you how to get started using TechNexion camera modules on PICO-IMX8M Mini board.
You must have the background knowledge to modify the kernel configuration, rebuild, and replace the kernel and the device tree source (DTS).
This article uses the PICO-PI baseboard as an example, based on the Yocto 4.2 (Mickledore) 2024Q2 Release. The corresponding Linux kernel version is 6.1.55_2.2.0.
📸 Supported Camera Modules
| Camera Series | Products |
|---|---|
| TEVS | TEVS-AR0144 TEVS-AR0145 TEVS-AR0234 TEVS-AR0521 TEVS-AR0522 TEVS-AR0821 TEVS-AR0822 TEVS-AR1335 |
🧩 Supported Boards
| SoM | Board |
|---|---|
| PICO-IMX8M-MINI | PICO-PI PICO-WIZARD |
🔧 Hardware Setup Instructions
Kindly refer to the following pages:
🔗 PICO-PI-IMX8M-MINI
🔗 PICO-WIZARD-IMX8M-MINI
💻 Prepare Yocto demo image for testing TechNexion camera
To test TechNexion cameras, you will need a Yocto-based demo image that includes the necessary device tree blobs and camera drivers.
🔽 Downloading the Demo Image
Prebuilt demo images are available for download on TechNexion's official server.
Download Link:
🔗 Demo Image for PICO-IMX8M Mini
💾 Flashing the Image
You can flash the image to either e.MMC or an SD Card using one of the following methods:
1. Using uuu Tool (Universal Update Utility)
TechNexion provides a guide to flash the image using the uuu tool:
🔗 How to Flash with UUU
Before flashing, ensure the board is set to Serial Download Mode in the boot configuration. You can refer to Hardware Setup Instructions for more details.
2. Using ums Command in U-Boot (USB Mass Storage)
Alternatively, you can write the image directly to flash storage over USB-OTG using U-Boot’s ums command:
🔗 Using UMS in U-Boot
The board must be booted with a version of U-Boot that supports the ums command. Typically, this is done from the existing e.MMC.
🛠️ Build Yocto
TechNexion supports building a Yocto-based Linux image tailored for camera modules using the following kernel and branch.
📦 Supported Linux Kernel
| Linux Kernel Version | Yocto Branch |
|---|---|
| 6.1.55 | tn-imx_6.1.55_2.2.0-stable |
📁 Source and Build Instructions
🔗 Fetch Yocto Source
📖 Build Yocto (Instructions for PICO-IMX8MM)
📸 Camera Testing Instructions
Specify Camera DTBO in U-Boot
-
Connect the debug console cable to the baseboard.
-
Power on the board and interrupt the boot process. Keep pressing
Enterwhen the following message appears:Hit any key to stop autoboot: -
Set the correct camera overlay (DTBO) using the U-Boot environment variable:
u-boot=> setenv dtoverlay $dtoverlay tevs
- Save and continue the boot process:
u-boot=> saveenv
u-boot=> boot
🎥 Start Camera Video Stream via GStreamer
Check Camera Availability
Use the v4l2-ctl tool to list connected video devices.
$ v4l2-ctl --list-device
Example output:
i.MX6S_CSI (platform:32e20000.csi1_bridge):
/dev/video0
In this example, /dev/video0 is the capture device connected via CSI.
Launch GStreamer Pipeline
Replace <res_w>, <res_h>, <x>, and <y> with your desired resolution and screen dimensions:
$ gst-launch-1.0 v4l2src device=/dev/video0 ! \
video/x-raw, width=<res_w>, height=<res_h> ! \
imxvideoconvert_g2d ! \
waylandsink window-width=<x> window-height=<y> sync=false
🚨 Troubleshooting
Ensure camera device tree blob overlay(DTBO) is specified correctly in u-boot.
u-boot=> printenv dtoverlay
dtoverlay=ili9881c tevs
We can check whether camera have been initialized correctly.
For TEVS cameras:
$ dmesg| grep tevs
[ 2.886537] tevs 1-0048: tevs_probe() device node: tevs@48
[ 3.457747] tevs 1-0048: Version:24.10.0.1
[ 3.468184] tevs 1-0048: Product:TEVS-AR1335, HeaderVer:3, MIPI_Rate:800
[ 3.505338] mxc_mipi-csi 32e30000.mipi_csi: Registered sensor subdevice: tevs 1-0048
[ 3.567084] tevs 1-0048: probe success
Ensure camera device tree blob(DTB) is specified correctly.
$ dmesg -t | grep -i model
Machine model: TechNexion PICO-IMX8MM and PI baseboard