I have problem witch writing flash to nRF52840 dongle by Raspberry PI 3B+. I tried to change the bootloader and when I was cleaning the memory with the "nrf5 mass_erase" command, raspberry said that nothing cleared, and since it didn't clear, I thought I could unplug it. I know you shouldn't pull it out if you clear the flash memory but I didn't know I did it.
Now when I connect it to the computer it does not detect me at all. I have 1.8V between the VDD and GND pins, which means that the memory is cleared by default. Due to the fact that I cut off the device with the SB2 cutter and connected the SB1, ensuring external 3.3V voltage for VDD and GND. I tried to upload the software but I have the following errors. I looked at the internet and the problems were similar but in my case I didn't want to help.
I wanted to do what is in the video: https://www.youtube.com/watch?v=R5wub5ywzTU&list=PLKGiH5V9SS1g90s9mHTMPJT1i8N4fXWNT&index=2
Openocd.cfg
# Raspi1 peripheral_base address
# bcm2835gpio_peripheral_base 0x20000000
# Raspi2 and Raspi3 peripheral_base address
#bcm2835gpio_peripheral_base 0x3F000000
# Raspi1 BCM2835: (700Mhz)
# bcm2835gpio_speed_coeffs 113714 28
# Raspi2 BCM2836 (900Mhz):
# bcm2835gpio_speed_coeffs 146203 36
# Raspi3 BCM2837 (1200Mhz):
# bcm2835gpio_speed_coeffs 194938 48
# pi interfece
interface bcm2835gpio
bcm2835gpio_peripheral_base 0x3F000000
bcm2835gpio_speed_coeffs 194938 48
bcm2835gpio_swd_nums 25 24
# transport
transport select swd
# target
set CHIPNAME nrf52840
source [find target/nrf52.cfg]
# Uncomment & lower speed to address errors
adapter_khz 800
init
targets
reset halt
I find i must set REGOUT0 but i dont't know how