I wanted to use a microSD card and a external DAC with SPI-A. Individually both seems to be working with the same initialisation. (where for DAC GPIO is used for selection).
But when I use the two at the same time then only microSD works. The DAC does not get reset to zero, it stays in its previous state.
Please guide me on how single SPI is to be used with 2 slaves.
Ravi,
Typically, you would tie SPICLK, SPISIMO, and SPISOMI to both slaves. SPISTE would not be connected. Instead, two individual GPIOs would be used and manually driven for each of the slaves. This really is the only hardware configuration that you need. I have attached a diagram of how this HW connection would look.
The rest would come down to how your software is configured. Are you driving your CS pins properly? Are you writing the correct data to the correct device? Do the slaves get configured properly, but just not operate as expected?
