I am working with the nrf51822 eval kit and custom boards based on the Laird BL600 module. I am using SDK v5.2.
I am trying to connect to external Flash (Microchip SST25VF016B) through SPI 1. No matter what I do, the Flash returns 0xFF.
I have tried the nrf51822 SPI loopback example, it works fine. Indeed, I can loop back MISO<->MOSI and read the correct data. So the nrf51822 chip seems to be working, at least with itself.
I also took the Flash chip and hooked it to an Arduino Pro Mini. With that setup, I can talk to the Flash just fine. So I am pretty confident that the Flash works and that I am hooking it up correctly as I have the two rigs next to eachother for reference.
I have made sure the mode settings and frequency are the same between the Arduino and the nrf51822. Also, just to try it, I used many different mode/frequency combinations. Nothing works. No matter what I do, I always get back 0xFF on the MISO line with the nrf51822.
I don't have a scope, unfortunately, so I can't debug at that level.
Anyone have any idea what could be causing this? Any idea at all? I am wide open as I am pretty much stuck and have been trying everything.
I posted the code I am using for reference. Here is the Arduino test (which works and properly prints the Flash ID): gist.github.com/.../6fd9709f76584b8af792
Here is the nrf51822 test (which doesn't work, and just returns 0xFF every time): gist.github.com/.../2bedc0ce3f7e2251174d
For the nrf51822, I am using the provided spi_master class. I have thoroughly gone through this and not changed anything in there except the frequency.
