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remap tx and rx on s20

Posted: 14 Jun 2017, 22:25
by bobbybeans
Hey there. somebody a while told me it is possible to remap the tx and rx but first I have to disable it. Currently i have firmware r147. however i don't see the options.. Is it there somewhere that I am missing or do i have to update the the latest version? it so what version?

Re: remap tx and rx on s20

Posted: 15 Jun 2017, 10:42
by toffel969
bobbybeans wrote: 14 Jun 2017, 22:25 Hey there. somebody a while told me it is possible to remap the tx and rx but first I have to disable it. Currently i have firmware r147. however i don't see the options.. Is it there somewhere that I am missing or do i have to update the the latest version? it so what version?
I don't think you can just remap. You can however use gpio 1&3 for sensors/actors/i2c. Therefore you have to disable serial in advanced tab. After a reboot you should then be able to chose gpio 1/3 as SDA/scl or when configuring a sensor

Re: remap tx and rx on s20

Posted: 21 Jun 2017, 11:24
by bobbybeans
hey there just an update for everyone in r148 in the advance settings you can disable serial then upon reboot you can use those as standard IO pins.
remap was the wrong terminology my bad

Re: remap tx and rx on s20

Posted: 21 Jun 2017, 12:07
by LisaM
bobbybeans wrote: 21 Jun 2017, 11:24 hey there just an update for everyone in r148 in the advance settings you can disable serial then upon reboot you can use those as standard IO pins.
remap was the wrong terminology my bad
There is a risk in using gpio1/3 for sensors, at bootup the sensors might get confused by the serial output the esp is doing...

Re: remap tx and rx on s20

Posted: 22 Jun 2017, 21:45
by bobbybeans
but wouldn't that be counter productive of the option to disable serial? if you select disable serial It should disable it? I understood it as disable serial, disables the entire serial unless you put it back into flash mode?

Re: remap tx and rx on s20

Posted: 22 Jun 2017, 21:52
by Shardan
You can always flash, even if serial is disabled.

Disabling stops serial monitoring and you can't send commands via serial to the ESP.
This can be reverted if you enable serial again - disconnect sensors/actors before re-enabling!

Anyways there are some disadvantages.
Using them as sensor input might bring some sensors into trouble, others might work.
Using them as output will definitely trigger actors on Tx on bootup as the ESP always
sends some data on bootup.

Regards
Shardan

Re: remap tx and rx on s20

Posted: 27 Jun 2017, 15:51
by toffel969
Expirience thus far with GPIO 1&3

Output:
Relais -- flicker on boot depending on application this is acceptable or not
MOSFET -- ESP will not boot !!! (not sure if it was 1 or 3 or both)

Input:
DHT11 -- works on both
I2C -- works


It is probably best to avoid them, but, sometimes the only choice (if you want I2C on a SONOFF for example)

Re: remap tx and rx on s20

Posted: 02 Jul 2017, 01:26
by LisaM
https://www.letscontrolit.com/forum/vie ... f=2&t=3263
GPIO 13/15 are also available on the S20....