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I'm using AD7190 with STM32F103 for data logging. The datasheet of the ad7190 said that the DOUT/RDY falling edge can be used as an interrupt to a processor since it will go low to indicate the completion of a conversion. I'm using the continuous conversion mode of the ad7190, so I need to continuously monitor this pin. The DOUT/RDY pin of the ad7190 is connected to the MISO pin of the stm32f103.

How can I set the MISO pin of the stm32 as an external interrupt pin to detect the falling edge while it was set as MISO pin?

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  • \$\begingroup\$ Ah, let me read the datasheet: (1) analog.com/media/en/technical-documentation/data-sheets/…. The datasheet says the following about the DOUT/RDY pin: (2) In addition, DOUT/RDY operates as a data ready pin, going low to indicate the completion of a conversion. (3) If the data is not read after the conversion, the pin goes high before the next update occurs. (4) The DOUT/RDY falling edge can be used as an interrupt to a processor, indicating that valid data is available. (5) With an external serial clock, the data can be read using the DOUT/RDY pin. / to continue, ... \$\endgroup\$
    – tlfong01
    Jan 31, 2021 at 6:15
  • \$\begingroup\$ (6) With CS low, the data/control word information is placed on the DOUT/RDY pin on the SCLK falling edge and is valid on the SCLK rising edge. (7) So I think there are two ways to read the conversion results: (a) Using SPI: (i) Set CS low, (ii) use SPI to read results, (b) Use external clock, and read results, say from any GPIO input pin connected to DOUT/RDY pin. In other words, you need another two purpose GPIO input pin which, when interrupted by the DOUT/RDY signal, can proceed to read the results, as clocked by the external clock. \$\endgroup\$
    – tlfong01
    Jan 31, 2021 at 6:25
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    \$\begingroup\$ You don't need the one pins to be both an interrupt input and MISO at the same time. Start off with it configured as an interrupt, then when the int fires, reconfigure the pin as MISO. When the SPI transaction is complete, reconfigure the pin back to being an interrupt. Rinse and repeat ... \$\endgroup\$
    – brhans
    Jan 31, 2021 at 6:37

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I ended up connecting another pin to MISO and config it as external interrupt pin.

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