5 years, 3 months ago.

flashing a raw nrf51822 with the RedBearLab MK20 board

I've designed a custom board around the MDBT40, an NRF51822 powered module. This is the same module the BLE Nano uses, so I based my schematic on the Nano, and am using the RedBearLab MK20 USB board to program it. I've connected my custom board to the MK20 as follows:


VDD to VDD, through a 3.3v regulator

SWCLK to DCLK with a 12kOhm pulldown resistor on the line


My custom board is giving the MDBT40 power as confirmed by the LED and a multimeter. However, I am unable to flash the bootloader to the chip. Dragging the RedBearLab provided bootloader.hex to the MBED drive results in "can't complete the operation because some of the data in 'bootloader.hex' can't be read or written". Connecting the same 4 pins using the same cable on an authentic RedBearLab BLE Nano results in a successful flash. Is there a step I've missed? Do I require a different programmer to initialize the chip?

I am having exactly the same problem. Did you find a solution?

posted by darryl mattocks 08 Oct 2016

darryl - nope, no dice. I just bought a J-link, works fine. First, connected it to a BLE Nano and used the read commands to pull the hex off it, then connected it to my custom board and wrote the same hex. Works fine, but seems a very roundabout way to do things.

posted by Chris Millsap 12 Oct 2016
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