Artekit AK-CMSIS-DAP Problem


Hi, my name is Nafis. I’m just started to learn electronics and needed the ARM programmer. I have bought EFM32HG308 and found your project. Compiled firmware from files that shared on github. But after connecting to PC and starting Keil UV5, in debugger settings it writes “RDDI-DAP error”. Checkbox “SWJ” and in interface “SWD” is chosen. When i try to erase target or download code, i have popup window with message “RDDI-DAP Error” and then “Error: Flash Erase failed - Target DLL has been cancelled”. Firmware compiled without any errors. I does not changed source files or code.

I’m testing firmware on own proto board maked on Oshpark. It have not any buffers or buttons. Just capacitors, few resistors and TVS SP0503BAHT on usb line for esd protection.

System is Windows 10 Pro, Keil uVision updated EFM32 packages 11.05.2018), for EFM32HG programming i use J-Link that is got from my friend to make own programmer.

Can you help me, resolve this problem? There is some code in firmware that checks buffers or anything else and may conflict with my board?

This is screenshot of Keil debugger settings window.

Thanks a lot for your work and answer anyway. Best regards.


Hello @Bloodhealer,

If I get it right, you are having problems with your own version of the AK-CMSIS-DAP project, and not our board for sale. Correct?

If so, it could be useful to see the schematics of your JTAG board and how you connected it to your target boards.

As far as I know, there are no control pins to read the buffers state, so it should work as is.

There are some debug messages visible through the UART, by enabling DAPDEBUG in the dap_debug.c file.

CC @ruben


Hi Ivan. Thanks a lot for your attention and help.

Yes, that’s right.

Sorry, i havn’t schematics because PCB was designed in SprintLayout 6. There is no schematics editor in this software.But if i would have some free time, i will make it. Anyway board is very simple, like STM32 BluePill board, with minimal additional components, USB connector and two pin headers( include SP0503BAHT TVS on USB D+, D- and VUSB lines in my case).

The “RDDI-DAP Error” string in Debugger settings displayed in both with or without target connected to debug pins.

I’ve defined DAPDEBUG in the dap_debug.h ]( file. But there is no messages in terminal window.

I doesn’t checked JTAG connection, and my be it works. If it does not, i will check board to mistakes.

Will this firmware work on EFM32HG322? My friend have SLSTK3400A Starter Kit board and i can check it.

Best regards.

P.S. Can you send me already tested, compiled firmware? It will be helpfull for me.


Hi @Bloodhealer,

  1. How are you downloading the firmware to the EFM32? Using another JTAG?
  2. Are you flashing the bootloader and then sending the firmware with this procedure? Or you just modified the linker script of the AK-CMSIS-DAP firmware to make it start at the right flash position?

I can get you the binaries we use for production, but we only flash the bootloader and then the main firmware using the above procedure. I’m out of office these days, but I can get them remotely with some patience.

Note that debug messages are output through the UART. You need a TTL-to-RS232 converter to connect the UART to a PC and see the messages with some application like TeraTerm.

I’m not quite sure. I’m not a big user of the EFM32 line (I cheer for STM32 in here :slight_smile: )

  1. I’m downloading firmware with J-Link through SWD. Cortex-M0 and M0+ have not full JTAG interface, as i know.
  2. I don’t modify linker and do not download bootloader to the EFM32. I just download compiled firmware.

Thanks it is will be helpful. I will try to flash bootloader and load firmware through it. May be problem in it.


@Bloodhealer please find here below the files we use for production.

ak-cmsis-dap-bootloader.bin (6.4 KB)
ak-cmsis-dap.bin (30.4 KB)