TMDS64EVM: OLED Display Not working

Hello,

Ok, I've got a couple questions here.

1) I usually see display controlled by Linux, but I DebugP_Log used in MCU+ applications. Which core are you using to control the display, and what SDK / OS is running on that core?

2) What display are you using?

3) If you are using Linux to control the display, how did you modify the Linux devicetree?

Regards,

Nick

Hi,

So I'm using OLED on I2C by using R5F0-0 
And it's not using any RTOS on it.

And I'm following the user guide AM64x / AM243x Evaluation Module User's Guide (Rev. A)

And I'm trying to get this runing
Display Interface with part number OSD9616P0992-10.

Hello,

I am sending your thread over to a team member more familiar with our MCU+ SDK. Feel free to ping the thread if you do not get a response within several business days.

Regards,

Nick

Hello Ojasvi,

I am going to help you with the problems regarding OLED display.

So, I need couple of clarifications, is this the display already attached to the AM64x EVM or is it a custom part you are trying to interface ?

Please check images below.

Regards,

Vaibhav

Hi Vaibhav,

Thanks for the help. 
I'm using the OLED already attached to AM64x EVM. The same one as shown in above image you sent

Hi Ojasvi,

Thanks for the confirmation, let me check myself.

Allow me sometime to recreate this.

Regards,

Vaibhav

Sure, 
Share with me the code if you are able to make it work.

Hi Ojasvi,

I am able to reproduce this.

When I pass the address 0x3C to the I2C Probe API having MAIN DOMAIN I2C1 as the peripheral set, I see its not detecting the slave.

I think some sort of interfacing issue.

I believe we might need to have some physical connections? Can you also check the AM64x schematics meanwhile I check myself as well ?

Regards,

Vaibhav

Hi Ojasvi,

I am successfully able to interface I2C with OLED. It is working.

Well few things to keep in mind.

So there are many ways to initialize the SoC, some of them being:

via SBL: software-dl.ti.com/.../EVM_SETUP_PAGE.html

via SD CARD: dev.ti.com/.../node

Now, if I go the route of SBL, and I try to probe the OLED which is at slave address 0x3C, I am not able to probe it with SoC_I2C1.

But, I have noticed when we go via route of  booting Linux (with SD Card boot mode set), the OLED powers on and when I try to run the same program it works fine.

I was able to probe the OLED (at 0x3C).

Main Root Cause of it not showing up via SBL could be that it is not powered on/is not supplied sufficient power.

Please ask any other doubts if you have any and meanwhile I will check how I can make the OLED up and running via SBL. I will check internally with HW Team.

Regards,

Vaibhav

Hi Vaibhav,

Thank you for the reply. 

Unfortunately, I can't use Linux on A53 because it will mess us with my objective of debugging the other cores using IPC. So, I'm not planning to even boot Linux. 
Is it possible to use SD card boot mode but not using/ programming Linux at all ? because I want to use the OLED with one of the R5 cores. or
Can you please look into if I can somehow make OLED work with OSPI boot because I want to just use it with R5F core without having any Linux on A53 

Hi Ojasvi,

I am going to get back to your thread and look for possibility to have OLED interfaced with SoC_I2C1 via R5F core.

Please allow me next time week to put out my thoughts on this.

Again, thanks for your patience.

Regards,

Vaibhav

Hi Vaibhav,

Any update on this ?

Hi Ojasvi,

Thanks for your patience.

Ojasvi Kumar said:

Is it possible to use SD card boot mode but not using/ programming Linux at all ?

Did you get a chance to use this method of SoC Initialization and probe the OLED ?

I am still checking with hardware experts on this.

Regards,

Vaibhav

Hi Vaibhav,
Yeah, I tried this, still not getting anything on OLED. Do you have any update on this? 

Hello Ojasvi,

I am currently checking the voltage supply on the pins 7 and 10 of the 14 pin connector for OLED.

I am checking the voltage supply for two modes, first when we set it to OSPI boot mode and the second when we set it to SD card boot mode.

This way I can identify the root cause which might be that enough voltage is not supplied.

Please watch this space for response within a couple of hours.

Regards,

Vaibhav

Hi Ojasvi,

I have some updates.

So here is what I found out when I probed lines 1, 7 and 10 from the 14 pin connector.

I see that the Vcc is fine.

I feel like it might be more to do with GPIO_OLED_RESET pin.

I am trying to see possibility by toggling this pin.

Regards,

Vaibhav

Hello Ojasvi,

GOOD NEWS.

I have been able to probe the OLED and now the SoC_I2C1 is able to probe OLED which is at 0x3C.

I have written a code using the TCA6424 drivers.

Took me sometime to correct the errors, but I was able to make it.

Allow me another hour to put out the code here in the form of an FAQ.

Regards,

Vaibhav

Hi Vaibhav,

That's good news. Thank You for the support. 
Where can I find this FAQ?

Regards,
Ojasvi Kumar