Known Issues and Errata¶

This section describes / outlines any known issues with the MitySOM-5CSX Embedded Vision Developer's Kit.

1. Certain HDMI connections can corrupt the Basler I2C / Camera interface¶

Description
Critical Link has received reports that access to the Basler dart cameras I2C control port fails when certain HDMI devices plugged into the carrier card during power up. Symptoms of the problem can be note by I2C controller time out errors displayed on the console similar to messages shown below (these messages can also be seen if you type the dmesg command on the linux prompt). When this situation occurs, the pylon library is unable to communicate with the Basler cameras, and the demonstration software will fail to start up the camera acquisition.

mitysom-5csx-vdk login: root
root@mitysom-5csx-vdk:~# cd sw/demo_app/src/
root@mitysom-5csx-vdk:~/sw/demo_app/src# source /home/root/setup_dual.sh
root@mitysom-5csx-vdk:~/sw/demo_app/src# ./demo_app
Build Info: Aug 18 2017 22:10:57
Going to use Pylon Stream to capture and display images.

i2c_designware ffc05000.i2c: controller timed out
i2c_designware ffc05000.i2c: controller timed out
i2c_designware ffc05000.i2c: controller timed out
i2c_designware ffc05000.i2c: controller timed out
Enumerated 0 cameras. FPGA expects 2. Exiting.

The VDK board connects a local 3.3V I2C bus to the Basler dart camera BCON interfaces as well as to the DDC/I2C bus interface on the HDMI connector via a 3.3V to 5.0V level translator. Investigation has shown that the HDMI devices that cause problems during power up are back-powering the HDMI +5 V / I2C interface when the carrier card is off. This results in latching up either the level translator or the dart camera interface when the carrier card is powered on.

Affected Hardware
All carrier cards inlcuding 80-001038RC-1C.

Fixes / Work-arounds
Work-Around : To work around the problem, power the VDK kit carrier card up prior to connecting the HDMI cable / device into the carrier. Once the card is properly powered up, you can connect the HDMI cable / device. Customers with a configuration exhibiting this issue have reported this sequence will allow proper use of the card and communication with the cameras.

Fix : The I2C bus will be separated into 2 busses on -2 revisions of the VDK. The HDMI I2C/DDC interface will be level converted and routed to a separate I2C interface via spare FPGA bank pin connections. Steps will be taken to protect the carrier card from any latch-up conditions on the HDMI DDC interface. Revision -1 boards may be reworked to implement this change. Customers with -1 revision hardware requiring the fix should contact Critical Link for resolution.