ESP8266 Community Forum

- Sat Feb 13, 2016 8:45 am #41029 I've got a problem...

I'm using an ESP-07 for two switched outputs (GPIO0 and GPIO2) with local control switches on GPIO12 and GPIO13.

Functionally, everything works fine - but...

Whenever the GPIO2 output is On (Low), the blue TX LED is lit (seemingly continuously)...

The pins aren't adjacent on the ESP-07, so that virtually rules out a solder bridge or other short circuit, it doesn't relate to cabling external to the ESP-07 and I can see nothing in my code that could be causing this weird effect.

The only thing I've managed to unearth after hours of Googling is that GPIO2 doubles as "U0TXD in Function 4" - but I have no idea what that implies or how I might have invoked 'Function 4', so that really doesn't offer much in the way of clues.

Can anybody help???

This is driving me nuts...

- Sat Feb 13, 2016 9:33 am #41035 Is that causing a problem?
GPIO2 from what I have found can be Uart1 Tx line [ use for debug] there is no Rx
Is it the same Blue led? or maybe 1 of 2 blue leds Uart1 and Uart0

- Sat Feb 13, 2016 5:16 pm #41064

Is that causing a problem?

It's not causing any functional problem (I.e.e everything in terms of inputs and outputs works as I expect it to), so there's no issue in that score but, as far as I can tell, it shouldn't be happening under 'normal' operation, and I certainly wasn't expecting it.

GPIO2 from what I have found can be Uart1 Tx line [ use for debug] there is no Rx
Is it the same Blue led? or maybe 1 of 2 blue leds Uart1 and Uart0

As far as I can determine, it's the same blue LED that flashes during uploading of the sketch to the ESP, but I can't be 100% sure - when you're in your mid-60s, with poor eyesight, it's very difficult to see exactly where the blindingly bright blue light is coming from!!!

- Sat Feb 13, 2016 5:47 pm #41068 Just to add to what I wrote for xtal's reply...

According to this (relating to uploading sketches to the ESP-07/12):
http://ediy.com.my/index.php/blog/item/ ... rduino-ide

"Click on Upload button from the Arduino IDE, the blue LED which is wired to TXD (GPIO1) will start blinking rapidly indicated uploading process is going on."

So I can come up with no obvious reason for what I'm seeing...