Establishing serial communication over UART instead of USB in MAX25405 EVKIT

It is written in command list which I posted. It is following line:

cd mbed-os
git checkout 0fdfcf7350896a9c0b57c4a18237677abfe25f1a

I found this commit ID somewhere on the internet. Someone was facing simmilar issue but with different firmware and library. I tried it and I was able to compile firmware with this version. But I had to fixed one old python script which come from this old mbed-os. See comments in code snippet in my previous comment.

Currently I am out of home. I will of course try backup stock firmware before flashing my own. I always do this when possible. I will try this with MAX32620FTHR next weekend. If you want to do it yourself, you can use some of following commands. They come from my notes which comes from my last attemps of backuping firmware from MAX32625PICO board by other debug probe. Note that I recommend using openocd bundled as part of Maxim SDK (from C:\Maxim\... directory). In my case mainline openocd never worked with their chips. Last time I faces issue when mainline openocd successfully erased my MAX32625MCU but was unable to program new firmware (efficiently it bricked my MCU). Most probably Maxim patched openocd somehow to support their MCUs better. Following commands I post without any warranty. Since I am out of home I cant test that they work with MAX32625FTHR also.

"C:\Maxim\Toolchain\bin\openocd.exe" -s C:\Maxim\Toolchain\share\openocd\scripts -f "path to config probe depending on debug probe used (ST-Link, J-Link, MAX32625PICO, ...)" -f target\max32625.cfg -c "reset"

After connecting to target open putty and connect using telnet to localhost:<telnet port which can be determined from openocd output>. In telnet window execute:

halt
dump_image max_stock_fw.bin 0x00000000 0x00200000

max_stock_fw.bin willget created in working directory. Run dump_image three time with different file names and after dumping check that all three files are the same and no bit error occured when transfering firmware.

If I burn the Arduino Bootloader into the FTHR board then I'll have to rewrite the entire code for gesture recognition. I don't think I can write such complex codes. I just want the gesture data from MAX32620FTHR board over UART so that it can be read by Arduino.

Yes, I tried sending ping and poll request over UART from Arduino to the MAX32620FTHR but still I'm getting the same response as 240. I'm testing it out now. Will update in an hour or so. 

Only value 240 is wrong and I guess it have nothing to common with commands transmitted by MAX32620. Usualy it indicates wrong baudrate or something like this. Note that all response from MAX32620 are always longer than one char which also indicates bad baudrate. Did you initialized your Arduino Serial with baudrate 115200?

Because I am out of home I cant test this firmware yet, but after I test I will give you know.

Yes, the Arduino baud rate is set at 115200. If it is anything more or less, the serial monitor just prints gibberish because of baud rate mismatch. 

I did it without --scm none but I think this has no impact on result. I think scm means that it initializes git repo for your project but I think it has no impact on operating system which is always downloaded using git.

Yes I have tried mbed new . --scm none but it did not work. I believe this just relates to version control. I believe misaz has the solution with git checkout 0fdf...

I don't have a backup either.

UPDATE:

The main.cpp file has a function to check if any command request from user has been sent to the MAX32620FTHR board. So upon initializing the serial comm. in Arduino, I'm sending the following command -

Serial.write("cmd_poll");

The main.cpp then sends the poll result over serial comm. which I'm continuously polling and reading the status of Serial.read() in a variable. Still no success. 

It should be poll instead of cmd_poll. I recommend trying something more deterministic like ver (should return string containing firmware version).

Just to say that I got this to compile, but I took a slightly different route along the way.

I opened up Mbed Studio and created a new program from one of the available templates: mbed-os-example-blinky-baremetal-5

This uses Mbed version 5.15.

I then opened up Terminal in Mbed Studio and changed directory to the project folder.

I then used the two commands as per readme.txt

mbed add https://os.mbed.com/teams/MaximIntegrated/code/MAX32620FTHR/
mbed add https://os.mbed.com/teams/MaximIntegrated/code/USBDevice/

I then unzipped the firmware_framework.zip file.

I then used the following for my mbed_app.json

{
    "requires": ["bare-metal"],
    "config": {
        "main-stack-size": {
            "value": 65536
        }
    }
}

But when I tried to build the project it failed within Mbed Studio. This could well be because it is using ARMC6 as the default rather than GCC_ARM... I could probably change it inside Mbed Studio.

But instead I existed and opened up terminal and then manually compiled using the command given in the readme file, namely

mbed compile -t GCC_ARM -m MAX32620FTHR

And it worked.

Hope that helps.