Hi everyone, I am a beginner with the nRF52840 and I am looking at the example spi_pca10056 on SDK 16.0.0. What I've noticed is that at sdk_config.h file the pin configuration is:
SPI_SCK_PIN 26
SPI_MISO_PIN 30
SPI_MOSI_PIN 29
SPI_SS_PIN 31
Looking at the nRF52840_DK_User_Guide_v1.4 I can see on page 29 (Mapping of analog pins) that PIN 29, PIN 30 and PIN 31 are Analog inputs and on figure 21 (of the same page) PIN 26 is the SDA of I2C bus... On page 26 (External memory) the SPI pins for the external memory are P0.17, P0.19, P0.20 and P0.21
I am a bit confused.. why the example uses analogue pins for the SPI? I was expecting some digital pins instead, since the SPI pins are used by the external memory? In general what pins are available for the SPI and I2C?
Furthermore, the example saadc_pca10056 uses as an analog input the PIN P0.02 which is referred to as A_REF. Why in that case none of the Analog pins (page 29 -Mapping of analog pins) was not used and instead the P0.02 was used?
Thanks is advance
Nick
