Hi,
We have a custom board with BlueNRG-2 and wants it to act as a co-processor so it can be controlled through SPI from another MCU (STM32L4R9).
The BlueNRG-2 has been flashed with STSW-BNRG2N-V320 firmware through the bootloader interface.
DIO0 SCK
DIO2 MISO
DIO3 MOSI
DIO11 CS
DIO12 is pulled low to select SPI
To keep things simple I want to verify that firmware is working as expected so I pull CS low and monitor whether DIO7 go high. This never happens.
I have also tried calling the hci_reset function and monitor the SPI lines. SCK and MOSI provide the right output but MISO doesn't change. Prescale is used so output is below 1 Mbit/s
DIO7 is pulled low to avoid bootloader activation and DIO3 is low to avoid firmware updater to activate.
Do you have any suggestions on how to proceed?
One thing that might be a problem is that the hardware design was first made based on the recommendations for BlueNRG-2 so DIO4, DIO5, DIO6, ADC1, ADC2 and DIO13 is floating. FXTAL is 16 MHz and not 32 MHz as BlueNRG-2 allowed both frequencies.
