Hello, i am new to the whole NRF programming. I created my custom board with a NRF52811 SoC, without external LF crystal. I have been trying to get the device to advertise the BLE with blinky example, but i can t see it advertising with any device. I used RC for LF clock and i did flash softdevice 112 version 7.0.1. When i look for signal on spectrum analyzer i see the advertising channels where they should be and are quite strong.
Other than that my SoC works fine, i was able to program PDM microphone data sampling and writing it on the microSD card, led blinking works, just not BLE.
Does anyone have any idea what could be wrong? I put my code into the zip file.
Little update, i did over the weekend: I was trying the beacon example, with the same configuration as blinky, and i was running BLE scanner for 20 or so minutes and somewhere in between that interval it picked up the my board. After that i reset the device and i could not see it anymore. I have a feeling something is wrong with internal clock. I have 3 boards and it s the same with all of them.
Do you have a debugger on your board or the debugger interface? I would recommend you to start your application in debugger to see if there are any softresets happening on your device.Seeing the signal in spectrum analyzer and not able to pick up advertising seems strange.
The device is either advertising or not,I do not think that it would transmit corrupt packets due to misconfigured clock settings.
I did debug it with J-link and the code runs without any errors, that s why i posted a question. Can the 32MHz crystal affect the internal LF RC?
if you use
After much more debuging, also pcb design testing, antenna testing so i can eliminate hardware issues, what i discoverd is this: RC clock doesn t work for BLE on this chip, but i do get advertising signal using syntheised clock. What happens after that is that latency in advertisment keeps increasing with time, something that doesn t happen on DK emulating nrf52811. For a first few seconds of advertisment everything works fine, then the latency increases first by about 500ms, after that more than 1000ms, and it get s to around 1500ms... I belive something is wrong with the chip. I will try putting external 32khz crystal to the pins and see if that helps, but i can t shake the feeling that example code wasn t really tested on the actual nrf52811 chip.