How can I read data thru a GPIO configuread as EXTI?

[amelendez]

Posted on June 13, 2017 at 12:32

I'm trying to read an external ADC output.

The data are provided thru a DRDY pin.

When the DRDY falls, it generates an interruption in my STM32L1 (falling edge). Then, I must read the DRDY level eevery rising edge of a clock provide by the STM32L1 to the ADC.

Sould I configure the EXTI pin (PA3) in the callback function as input mode everytime the interrumption happens? (and then, before exiting to re-configure as EXTI)

[Uwe Bonnes]

Posted on June 13, 2017 at 13:21

As long as an GPIO is not in analog mode, IDR always reflects to logic level at the pin. So no need to redefine.

[amelendez]

Posted on June 13, 2017 at 15:14

Thanks Uwe. It's OK. The problem was in the protocol towards the external ADC

[Zt Liu]

Posted on June 13, 2017 at 17:25

2-wire serial interface? like this?

Should I configure the EXTI pin (PA3) in the callback function as input mode everytime the interruption happens? (and then, before exiting to re-configure as EXTI)

You can try that, I think it will work.

[Zt Liu]

Posted on June 13, 2017 at 16:34

I'd like to know the how the external ADC works? it's an IC? what's its name?

[amelendez]

Posted on June 13, 2017 at 16:42

It's an external Sigma-Delta 24 bits ADC

[amelendez]

Posted on June 13, 2017 at 17:33

Finally, it is not needed to reconfigure PA3

But I think that everytime DRDY falls during DOUT Mode, the interruption begins again.

Should I disable the interruption during DOUT Mode?