[MIMXRT] Install micropython on MIMXRT1020-EVK board

[Shards]

I thought it was about time we had another post relating to the now well developed MIMXRT port. I have used the Teensy boards successfully and it's a breeze loading micropython onto them using the vendor supplied Teensy loader App.

However, I have recently splashed out on a MIMXRT1020-EVK board and while there is a plethora of software to download to program the board nothing stands out as a way to simply copy the micropython build onto it.

I'm using Ubuntu Linux as my development environment.

I apologise if the required information is embedded in the existing post but it's probably worth having the info more accessible even if it is.

Any help appreciated.

[Roberthh]

The MIMXRT1020_EVK board has two USB ports. One is labeled J9, the other J23. J9 is the main USB port of the i.MXRT1021 MCU, and the REPL prompt will appear there. J23 is the USB port of the support MCU, which offers next to other a serial interface an OPEN-SDA interface and registers a drive when connected to the computer. One methods to upload Micropython is just copying the respective .bin file to that drive. Once the drive symbol disappears and reappears again, the firmware in installed. After a reset or power cycles you should have a Python REPL prompt at J9. I just verified that with today's daily build.
I use to set the jumper at J1 to the 3-4 position. Then the board is powered by J9.
Another method of uploading the firmware is by the J-Tag port. When you want to use that one, you have to remove J27 and J28.

[Shards]

I can get the drive showing fine via j23 and copy the latest bin to it. But on rebooting it is still running the default flashing LED program and no REPL on j9. Do I need to do something to clear down the internal memory? Or set another jumper? This is an out of the box board.

[Roberthh]

I have nothing special set. Using the USB upload method, J27 and J28 must be in place. Uploading by USB take quite a few seconds. You'll start it, then the green LED next to the support CPU flashes a while, then the drive symbol disppears and reappears. Then you have to push reset (SW3). While uploading, I have both USB ports connected to the PC, which is needed if J1 is in the 3-4 position.

[Shards]

With both USB ports connected the copy works fine. Once rebooted only the USB j9 connection is needed for the REPL.

Thanks for the rapid reply Robert.