Problem in communication of STM32F429 with STMPE811

[ali]

Posted on August 25, 2017 at 07:00

Hello,

I used STM32F429 for communicating with STMPE811 through SPI port.

In the beginning, I read chip ID of STMPE811 in order to make sure communication is correct.

Sometimes, IC doesn't return anything. I set the pins in order to make sure correct mode of SPI is

selected but it seems that IC is in reset mode and it didn't return anything.

I have to turn ON and OFF my board several times in order to get the functionality back.

I appreciate if someone could help me

Note: this post was migrated and contained many threaded conversations, some content may be missing.

[Vangelis Fortounas]

Posted on August 28, 2017 at 00:34

Hello Ali.

I use the same chip.

I observe that is sensitive to voltage variations(ripple, other noises,spikes).

Check the IN1 pin to be connected to VCC.

Check SDAT and A0 pins  (theese pins define SPI mode) and mode you use in your initialization software.

Check also VIO pin to be connected to VCC.

Check the clock speed not to be more than 1 MHZ.

There are no more HW points to check to have a good comunication with IC

About your initialization software you don't provide any information. so it is difficult to give some advice.

Regards.

VF

[ali]

Posted on August 28, 2017 at 01:30

Dear Vangelis,

All the points you mentioned are considered in my design. IN1 and VIO are connected to 3.3V and speed is about 500 kbit/sec. About noise, I will check more. Also, SDAT and A0 are set by MCU during power ON in order to make sure that my intended SPI mode is selected.

Initialization is performed by the sequence which ST provided in its app note.

One strange thing is that I have to read one byte twice in order to get a correct result. The same is for writing on the registers. If you don't mind, please help me

Ali

[Vangelis Fortounas]

Posted on August 29, 2017 at 19:24

Hello Ali

Community here , and i also, dont have any knowledge about your initialization code or code you use to read and write to

STMPE811, or

firmware you use , eg SPL, HAL, LL  or bare register.  It's impossible to guess what is fault .

For example you can provide to community your .IOC file and your main file and all relevant  code to your problem in case you use CUBE  for initialisation.

regards