I have not had time to make a video, but here are the basic instructions
You need a hardware programmer to fix this. e.g. JLink (clones work OK but not the small STM32 Jlink as the Reset pin is missing)
Programmers like this work OK
Unfortunately I checked eBay spain can I can't find any local
JLink Edu is also OK.
Download the JLink software from Segger.com
- Remove the battery
- Removed 4 screws at back of radio
- Remove volume knob
- Unscrew antenna and volume nut rings
- Carefully slide and open the radio.
The front is connected via a ribbon cable for the display / keyboard and also 2 wires for the speaker.
Probably unsolder the speaker wires and disconnect the ribbon cable from the main PCB, but this is not essential
- Solder wires to the pads for GND, CLK, DIO RST.
- Connect these wires to the Jlink.
On the Jlink it also has a VOUT and VIN. Connect the VOUT to VIN but I don't use this to power the radio.
Power the radio via the normal connectors to the battery, using a bench PSU
- In the JLink software (JFLASH)
Create a new project.
Select the MCU, which I think is listed under Freescale
MK22FN512 (either of the 2 possible selections e.g. "allow security"
- Select Connect in JFLash and check it can connect to the MCU
If it can't connect, check all your connections
- When you have a connection.
Select Target -> Manual Programming ->Erase Chip
- When the chip is erased it will now have copy protection removed.
- Download the patched bootloader
https://github.com/rogerclarkmelbourne/ ... loader.bin
- Open this file with JFlash. Select address as 0 (zero)
- Then program with this file
Target -> Manual Programming -> Program and verify
After the MCU is programmed with the patched bootloader, you should be able to use the normal upload process using the bootloader.
The LED should be permanently on when the bootloader is running.
I hope this helps a little.