Unhandled error: The data is not of the proper form

Seems every time I fix a problem, I hit another one! I’m getting this error right at the end of the compile

Unhandled error: The data is not of the proper form

I have added a switch to hold GPIO0 low during start up but I’m not getting any further.
Any assistance would be appreciated, I really want to work with this board!

Are you unable to download the program normally or is there a problem with the program compilation?
Can you provide complete error information or screenshots?

Here’s the full message

Sketch uses 78432 bytes (59%) of program storage space. Maximum is 131072 bytes. Initialising bootloader. Unhandled error: The data is not of the proper form

I get right to the end of the download process when this happens.

You can try to keep pressing the “USER” button, then release it after powering on via USB, and then download the program.

I tried this a couple of times with no change in the error message. :unamused:

You try to open the serial port, keep pressing the “USER” button, press the “RST” button once, wait for the serial port to print “bootloader Rev 1.0” and then release the “USER” button, then download the program.

Unfortunately I get the same result even when I have to bootloader notification.

Unhandled error: The data is not of the proper form

A lowercase ‘b’ is printed every second or so, is that normal?

Under normal circumstances, the serial port will not print any data after entering the bootloader.

Well I think I may have discovered something. I had a Beitian 220 GPS antenna soldered in and connected on the Tx Rx pins on the board. I have a HTCC AB02 on hand so I just tried to upload the sketch to that as a bare board. It worked! So I disconnected the GPS antenna module and tried the upload again and it worked on the AB01. So how would I connect the GPS module now?

AB01 has only one set of serial ports and has been connected to the download circuit. You can try the software serial port.

Thanks shaffer, I’ll give that a try :grinning: