Hi,
You could use Mbed Studio for compiling. If you modify mbed_app.json and add there line
“target.OUTPUT_EXT” : “hex”,
inside of “target_overrides”: {
Mbed Studio will compile and build .hex file. You can use Mbed Cli as well. And you can add / modify the same mbed_app.json file in Online compiler and it will compile hex-file.
Regards,
Pekka