1.8V issue in pocket beagle

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1

Hi All
I have been struggling to get a display controller working with pocketbeagle. I wrote SPI code for 9 bit transaction, which I think is correct then i realized that the 1.8V I/Os and signals coming out of pocket beagle is all 0.25V and not 1.8V. I thought the connected display board is shorting or something.Probed coupled of standale pocketbeagle board and yes it is only 0.25V?? What is wrong here? I am ruinning TI-SDK ARMStrong Image TI SDk 06.00.00.07!!! Any help appreciated? Powering is from USB cable attached to a PC.Swapped out cables and it doesnt seem to change anything
Anees

2

to clarify 3.3V signals are fine!!!

3

Hi All
I have been struggling to get a display controller working with
pocketbeagle. I wrote SPI code for 9 bit transaction, which I think is
correct then i realized that the 1.8V I/Os and signals coming out of pocket
beagle is all 0.25V and not 1.8V. I thought the connected display board is
shorting or something.Probed coupled of standale pocketbeagle board and yes
it is only 0.25V?? What is wrong here? I am ruinning TI-SDK ARMStrong Image
TI SDk 06.00.00.07!!! Any help appreciated? Powering is from USB cable
attached to a PC.Swapped out cables and it doesnt seem to change anything
Anees

You might need pullup resistors or need the I/O pins set to be pulled up?

4

Ok this was a vendor board and he is trying to take 1.8V power from pocket beagle PIN 21, this is AN0 which I think is analog input at 1.8V. he is doing it wrong. I dont think he should look for 1.8V supply from the pocket beagle, rather derive it from 3.3V.I gave my feedback thanks for the help!!!