Programming and crystal

[AndreaMontes]

I'm having issues trying to program a custom board with NRF52832_QFAB in DC/DC config. I couldn't reach a complete programming getting error in open ocd with two programmers:

1. STLink V2:

2. NRF52DK (JLink)

I have check connections between SWDIO, SWDCLK, VCC, GND, but I didn't get it.  Lastly, what I did was very my schematic and I found three issues:

1. Cap connected to DEC1 in recommended schematic is 100 nF, and I connected 10 nF

2. There is a missing capacitor in 36 pin that is one VDD. However, other VDD connections have their own decoupling cap.

3. I haven't realized that my ext, crystals have a different C.I, and I used the same load caps recommended in schematic by NRF52 product specification pdf.

I would like to ask if one of these three can be affecting programming cycle. I do really appreciate your help.

[bjorn-spockeli]

Hi Andrea, 

Issue 1 and 2: The incorrect DEC1 cap and the missing cap on pin 36 may lead to the chip not being programmable. So I strongly suggest that you fix these issues. 

Issue 3: SHould not affect the programming of the chip, but the incorrect load caps will most likely lead to the RADIO peripheral not working properly. So if you are using the RADIo for BLE, then you need to apply the correct load caps corresponding to the CL value of the crystals you have selected. 

Best regards

Bjørn