EDM-G TEVI Camera Usage Guide

Introduction

This article guides you how to get started using TEVI Series camera on EDM-G-IMX8M-PLUS.

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/12V power cable to plug in. If using vizionlink must have DC 12V/minimum 3A power adapter by barrel jack connector.
   (Note: EDM-G-WB 5V powered by USB Type C)
   

2. Prepare UART cable connect to debug console of EDM-G-WB

3. There are two MIPI-CSI-2 connectors we refer to CSI1 and CSI2. These are 70-pin board-to-board connectors from Hirose. Below is a picture of TEVI camera with CSI1 connector shown.

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:
Supported Release List

You can find the prebuilt Imaages page in Realease Notes, take YP4.0 2023Q2 for example :

Flash image to e.MMC or SD Card.

• Using 'uuu' to flash
  UUU

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

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 baseboard.

2. Power on board , and enter u-boot prompt mode.
   (keep hit enter when the "Hit any key to stop autoboot : " is shown.)

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

u-boot=> setenv dtoverlay tevi-ap1302

or

u-boot=> setenv dtoverlay tevi-ov5640

or

u-boot=> setenv dtoverlay vizionlink-tevi-ap1302

4. Continue boot process.

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

Start camera video stream via gstreamer

We can check whether camera have been link via v4l2 control command :

$ v4l2-ctl --list-device

Get the device number of camera capture device. As example we have camera on CSI1, that we can see /dev/video0 specify the capture device.

():
/dev/v4l-subdev0


():
/dev/v4l-subdev1


mxc-isi-cap (platform:32e00000.isi:cap_devic):
/dev/video0


mxc-isi-m2m (platform:32e00000.isi:m2m_devic):
/dev/video1

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

Ensure camera device tree blob(DTB) is specified correctly.

$ dmesg -t | grep -i model

Machine model: TechNexion EDM-G-IMX8MP and WB baseboard