enable reset control for generic esp8266 boards

[nerdralph]

change
esp01.upload.resetmethod=none
in esp8266/boards.txt to:
esp01.upload.resetmethod=ck

[rogerclarkmelbourne]

What does this change achieve ?

[nerdralph]

It is documented in esptool-ck; connect RTS to reset and DTR to GPIO0, then
upload automatically resets the ESP and triggers the bootloader.
https://github.com/igrr/esptool-ck
On Mar 31, 2015 7:45 PM, "Roger Clark" notifications@github.com wrote:

What does this change achieve ?

Reply to this email directly or view it on GitHub
#22 (comment).

[rogerclarkmelbourne]

I guess there is no harm to change boards.txt, but this form of resetting is very dependent on the type of USB to serial board you have.

[nerdralph]

I tried it with a cheapie pl2303hx under Windows 7, and it works fine.
On Mar 31, 2015 8:09 PM, "Roger Clark" notifications@github.com wrote:

I guess there is no harm to change boards.txt, but this form of resetting
is very dependent on the type of USB to serial board you have.

Reply to this email directly or view it on GitHub
#22 (comment).

[rogerclarkmelbourne]

OK. I have one of those, so I'll test, and I can generate a pull request if its easier for Ivan than for him to do the change himself

[igrr]

The reason I didn't set this as default is that when you open Serial Monitor in Arduino IDE, it pulls both RTS and DTR low, which puts the chip into bootloader mode. In fact some other terminals (screen?) also do that by default.
I can probably make this change but some people may get confused by this behaviour.

[rogerclarkmelbourne]

Ivan

I think this can be dependent on what USB to Serial adapter you have. There are loads of postings on various embedded forums where people have tried to make these adapters to both reset and also to enable the bootloader, but the consensus is that its not reliable and only works for some people.

There was a big and heated discussion on Arduino STM32 forum, and in the end I decided not to try to implement it.

[igrr]

For one esp8266 board I used the following solution:

This is supported in my fork of esptool using resetmethod=wifio. Seems to be very reliable and works with all the terminals I have. But for most people having to find a PNP and a capacitor may be an issue.

[nerdralph]

It makes no sense to disable it for everyone because it might not work
for some. We're talking a one-line change here that won't affect anyone
that is using manual reset.
On Apr 1, 2015 3:42 AM, "Roger Clark" notifications@github.com wrote:

Ivan

I think this can be dependent on what USB to Serial adapter you have.
There are loads of postings on various embedded forums where people have
tried to make these adapters to both reset and also to enable the
bootloader, but the consensus is that its not reliable and only works for
some people.

There was a big and heated discussion on Arduino STM32 forum, and in the
end I decided not to try to implement it.

Reply to this email directly or view it on GitHub
#22 (comment).

[igrr]

We're talking a one-line change here that won't affect anyone
that is using manual reset.

Okay, makes sense. Will fix.

[nerdralph]

"when you open Serial Monitor in Arduino IDE, it pulls both RTS and DTR low, which puts the chip into bootloader mode."
That is a minor nuisance if you want to do serial logging to have to unplug the RTS (and maybe DTR) line. It allows you to get started programming an ESP-01 with only a USB-TTL module and some dupont cables. I've been using mine that since it arrived in the mail a week ago.