esp32/README.md Added documentation about issue #49

[MrSurly]

Issue #49 is where the ESP-WROOM-32 contiually reboots after deployment
because it uses DIO flash mode.

[dpgeorge]

Thanks, but if you follow through all the steps of the README then this is already explained, although not as explicitly as you've done here. In particular line 73 mentions you might need to use DIO mode. Also that section discusses in detail how to configure these parameters in your own custom makefile/GNUmakefile (so as not to require changing the Makefile under source control).

Having a trouble shooting section is a good idea, but I'd suggest cutting it down to be not so verbose, just suggest that if the user gets a boot loop they should double check the flash mode and size settings for their board.

In the future we may have multiple board configurations so that people can build for their specific board (eg make BOARD=WROOM) and then this problem will go away.

[MrSurly]

In particular line 73 mentions you might need to use DIO mode.

I did miss that, but the question was answered by #49 -- though it wasn't clear that you needed to recompile, thus this writeup.

Having a trouble shooting section is a good idea, but I'd suggest cutting it down to be not so verbose, just suggest that if the user gets a boot loop they should double check the flash mode and size settings for their board.

Something like this?

Troubleshooting

• Continuous reboots after programming: Ensure FLASH_MODE is correct for your board (e.g. ESP-WROOM-32 should be DIO). Perform a make clean and rebuild.

[dpgeorge]

though it wasn't clear that you needed to recompile

It's stange that you needed to do a recompile.... it's probably related to the creation of bootloader.bin, which may depend on the flash mode.

Anyway, your suggested troubleshooting section above sounds good.