Program external BMD-300 with NRF52DK

[Maxim]

Hello, I am trying to program an BMD-300 using the NRF52-DK on a custom board,

The BMD300 is powered by the NRF52DK

BMD300 -> NRF52DK

SWDIO -> SH_SWDIO (pin 4) on P20

SWDCLK -> SH_SWDCLK (pin 5) on P20

VDD -> VTG (pin 3) / VCC (pin 2) on P20 (The BMD300 is powered by the NRF52DK)

GND -> GND_DETECT (pin 8) on P20 and GND on NRF52DK

The first time I connected the BMD300 to the board the command nrfjprog --family nrf52 -- recover was working and the BMD 300 was detected.

Then I use NRFGO to program the softdevice (S132) and keil to load the application, evething works fine.

But when i try to program again the BMD300 i could load any program, and command nrfjprog --family nrf52 -- recover doesn't work. NRFGO can't detect the board again.

Then i use P19 without success.

The program loaded by keil was ble_app_uart (pca 10040) from the sdk without any modification, i think the program made the BMD unaccesible but i don't know how to repair it.

Can someone please help me. Thanks, Maxim

[Maxim]

I've just try to wiring a flying BMD-300 with some wire and i got this log

nrfjprog --family nrf52 --recover --log
nrfjprog verion 9.3.1

FUNCTION: open_dll.
FUNCTION: open_dll.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: enum_emu_snr.
FUNCTION: connect_to_emu_with_snr.
FUNCTION: connect_to_emu_with_snr.
FUNCTION: connect_to_emu_without_snr.
FUNCTION: enum_emu_snr.
Device "NRF52832_XXAA" selected.
FUNCTION: recover.
FUNCTION: recover.
Found SWD-DP with ID 0x2BA01477
Found SWD-DP with ID 0x2BA01477
AP-IDR: 0x24770011, Type: AHB-AP
Found Cortex-M4 r0p1, Little endian.
FPUnit: 6 code (BP) slots and 2 literal slots
CoreSight components:
ROMTbl 0 @ E00FF000
ROMTbl 0 [0]: FFF0F000, CID: B105E00D, PID: 000BB00C SCS
ROMTbl 0 [1]: FFF02000, CID: B105E00D, PID: 003BB002 DWT
ROMTbl 0 [2]: FFF03000, CID: B105E00D, PID: 002BB003 FPB
ROMTbl 0 [3]: FFF01000, CI...