Tool/software:
Hi,
I'm working on a board that has an opto-isolated ADC 7038 with an SPI interface. If I talk to the 7038 directly without the opto-isolators it works fine, but when I try to talk to it through the opto-isolators and inverters it's not working.
The first thing I'm trying to do is to clean up the SSICLK signal and in order to do that I want to generate a square wave on that pin, PA2, and use it to improve the hardware. But, I'm not having much luck.
Right now all I'm trying to do is to switch PA2 from low to high. Here is what I'm doing:
1. Observe that RCGCGPIO is FF 7F - Gating clocks are enabled
2. Observe that PRGPIO is FF 7F - GPIO modules are ready
3. Set SSICR1 to 0 - Disable QSSI0
4. Set RCGSSI to 0 - Disable SSI module
5. Set Port A GPIODIR to 04 - Set PA2 as an output
6. Set Port A GPIODEN to 0xFF - Digital enable Port A
Then I write an 04 to GPIODATA (and also to 0x400583FC) and nothing happens. PA2 should go high, but it doesn't.
Can anyone see what I'm doing wrong here?
Thank you.