Hello,
We are using the Ixora Carrier Board in one of our products and use the LED_4 to display the state of the CAN interface.
Unfortunately in the new design revision 1.1A the LED_4 signal connection has been changed.
Is there is a possibility for the Apalis SOM to find out which revision of the Ixora board it is? At best already at device tree stage?
Thank you in advance, Jens Römer
Dear @JensRoemer,
thank you very much for using the Toradex Developer Community website.
I am sorry that this change was causing this issue on your side.
Normally this is not possible with our carrier boards, but I think think that in this specific case there is one thing we can use. On the Ixora V1.1, we stopped assembling the EEPROM IC14. This means that you can detect in SW if this device is available on the I2C bus and, if it is not there, it will mean that the module is running on the Ixora V1.1.
I know that this is not a perfect solution, but I think that would be a possible workaround for your problem.
I really hope this helps, please don’t hesitate to use again the Toradex Developer Community if needed.
Hi @diego.tx
On the Ixora V1.1, we stopped assembling the EEPROM IC14. This means that you can detect in SW if this device is available on the I2C bus and, if it is not there, it will mean that the module is running on the Ixora V1.1. I know that this is not a perfect solution, but I think that would be a possible workaround for your problem.
Our problem is, that we now need to adopt the device tree. We have another project and we designed it in a way that the device tree could be used for both hardware boards (our own and the Ixora). Unfortunately the pin that is now used for LED_4 is already used for another function in our board, so we cannot switch both pins unconditionally.
So we now see that it is needed to adopt hardware from time to time, and the need arises to detect the base board type and revision from the SOM - ideally at device tree stage. Do you have any suggestions how this can be solved in future? I think this will affect a lot of your customers once they have more than one product.
Thanks and regards,
André
You can detect hardware variant at Uboot and specify appropriate device tree when booting Linux.
Dear @JensRoemer,
I was thinking a bit more about this issue and maybe one thing that you could check is the pull status of the signal LED_4.
On the Ixora V1.0, this signal (SODIMM Pin Nr.146) is pulled down because it is connected to the LED circuit.
On the version V1.1, this signal is actually connected to the SDIO interface and therefore it is pulled up.
This is just an idea, I hope it helps. I wish you a nice day!
Hi all,
@diego.tx Thanks for your hint. We will try your suggestion.
But we (Jens and me) have thought about this topic again more general. We came to the clue, that it would be nice if the Apalis (or another SOM) could detect the hardware board (and revision) it is running on. This could work similar to the Raspberry Pi HATS [1].
If Toradex would have something like this as reference design, users could adopt the system to build their own boards. That would allow plugging SOMs with the same image into different hardware and configuring the hardware (device tree) automatically.
What is your feeling about this suggestion?
André and Jens
Dear @ahartmann,
this is definitely a valuable feedback and there have been already internal discussions about this topic.
The EEPROM which was mounted on the Ixora V1.0 it was actually there for a similar concept. I will definitely open this discussion again.
Thank again for your valuable feedback, I wish you a nice day.
Dear @diego, many thanks for your reply. Thanks for discussing this, I think this will be an improvement for all your customers.
Best regards, and Merry Christmas and a Happy New Year.
André
