PICO-IMX8M-MINI TEVI Camera Usage Guide

Introduction

This article guides you how to get started using TEVI Series camera on PICO-IMX8M-MINI.

Supported TEVI Camera Modules

Overview

• Connect debug console, power, and camera to board
• Prepare Yocto demo image for testing TechNexion camera
• Build Yocto
• Instructions for testing camera
• Trouble shooting

Connect debug console, power and camera to board

1. Prepare DC 5V power cable to plug in. (Note: PICO-PI-8M is powered by USB Type C)
2. Prepare UART cable connect to debug console of PICO-PI-8M
3. It's recommended to prepare a FPC cable to connect board will be more easy to use.

Prepare Yocto demo image for testing TechNexion camera

The demo image contains the required device tree blobs and camera drivers to enable TechNexion cameras.

Prebuilt demo images can be available for download via TechNexion's server.
Image Download Link:
pico-imx8mm_pico-pi-8m_yocto-4.0-qt6_qca9377_mipi5-1280x720_20230420.zip

Flash image to e.MMC

• Using 'uuu' to flash
  UUU

• Using u-boot's 'ums' Command to Write Flash Storage over USB-OTG
  UMS

Please refer to Instructions for testing camera section for camera testing steps.

Build Yocto

Supported TechNexion Linux kernel branch for TEVI camera modules

Fetch Yocto source
Build Yocto

Instructions for testing camera

Specify camera DTBO in u-boot

1. Connect debug console cable to PICO-PI-IMX8M-MINI.

2. Power on board , and enter u-boot prompt.

3. Specify camera dtb via 'dtoverlay' u-boot environment variable

u-boot=> setenv dtoverlay tevi-ap1302

or

u-boot=> setenv dtoverlay tevi-ov5640

4. Continue boot process.

u-boot=> saveenv
u-boot=> boot

Start camera video stream via gstreamer

Specify the capture device you just get and start gstreamer to get video stream on screen :

$ 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

Trouble shooting

Ensure camera device tree blob overlay(DTBO) is specified correctly in u-boot.

u-boot=> printenv dtoverlay

dtoverlay=tevi-ap1302

or

dtoverlay=tevi-ov5640

We can check whether camera have been initialized correcly.

$ dmesg -t | grep ap1302
or 
$ dmesg -t | grep ov5640

tevi-ap1302 1-003d: sensor_probe() device node: tevi_ap1302@3d
tevi-ap1302 1-003d: Product:TEVI-AR0521, Version:1. Lens:S84-IR FW:428 Freq:48M MIPI:816M, Version:1
mxc_mipi-csi 32e30000.mipi_csi: Registered sensor subdevice: tevi-ap1302 1-003d
tevi-ap1302 1-003d: probe success

or

ov5640_mipi 1-003c: supply DOVDD not found, using dummy regulator
ov5640_mipi 1-003c: supply DVDD not found, using dummy regulator
ov5640_mipi 1-003c: supply AVDD not found, using dummy regulator
mxc_mipi-csi 32e30000.mipi_csi: Registered sensor subdevice: ov5640_mipi 1-003c
ov5640_mipi 1-003c: Camera is found