ESP8266 Community Forum

- Tue Jan 05, 2016 10:28 am #37968 Hey all!

Not a super technical topic, but I have a few EPS-12E test boards that I ordered (these - http://www.aliexpress.com/item/ESP8266-ESP-12E-serial-WIFI-Industrial-stable-version-A-full-test-board-Full-IO-leads/32370570377.html) that I ended up not using for the project I originally intended, so for "fun" I'm hooking them up to various lights/etc in my house and sticking them in old cigar boxes.

Anyway, I haven't been able to find a schematic for the board anywhere, but there are a number of LEDs that seem to be lit when I'm using this board, even when CH_PD is pulled to ground. I'm GUESSING they are coming from the power/voltage regulation circuit, but I'm not 100% sure. The thing is, I'd like to run this thing off of batteries, in an opaque enclosure, so LEDs don't do a whole lot for me .

Any tips on how to reduce/disable/remove the power draw from these LEDs on this board? I'm guessing there are a number of people on the forums who have used this board quite a bit in the past so I'm hoping somebody might have some great ideas

Thank you as always!

- Tue Jan 05, 2016 4:08 pm #37994 The blue (on my board) LED next to the programming link on my 'yellow' board I'm pretty certain is a 'power applied' LED and is not controllable. I also have a couple of LEDs which glow very dimly when floating but turn off when set as inactive outputs. Then there's the 'wi-fi active' LED on the module itself.
Initially, try this to turn everything off.

Code: Select allpo 1 1
po 2 1
po 3 1
po 4 1
po 5 1
po 12 0
po 13 0
po 14 1
po 15 0

If your cigar box projects are going to be anything like permanent, I'd be tempted to use the non-reversible low tech method of crunching the LEDs in question with a fine pair of cutters. After all, each LED associated with a pin you're using is going to turn on when you toggle your SSR and there is no way around that.

- Tue Jan 05, 2016 4:23 pm #37996

The blue (on my board) LED next to the programming link on my 'yellow' board I'm pretty certain is a 'power applied' LED and is not controllable. I also have a couple of LEDs which glow very dimly when floating but turn off when set as inactive outputs. Then there's the 'wi-fi active' LED on the module itself.
Initially, try this to turn everything off.

If your cigar box projects are going to be anything like permanent, I'd be tempted to use the non-reversible low tech method of crunching the LEDs in question with a fine pair of cutters. After all, each LED associated with a pin you're using is going to turn on when you toggle your SSR and there is no way around that.

Thanks for the reply! And yes, it's the blue LED next to the programming jumper pins that I'm talking about. It's blue.

I'm all for low tech methods (I used a knife to pry off the resistor that connects CH_PD to vcc), but ideally I didn't want to break the board if I could help it. I have something like 6 of these, so if I loose one it's not a huge deal, but again I was hoping for a tested method, even if it's low tech . I'm not 100% sure that "crushing" the LEDs would solve my problem, would it? Another option I thought of was to just remove the LED and then bridge the connection with a bit of solder or something (or perhaps just leave the LED there and bridge the connection?)... but I'm a bit of a newb so am not sure how much purpose this LED is actually serving.

- Tue Jan 05, 2016 4:36 pm #37997 The thing you don't want to do is replace the LED with a link as this would increase the current drawn. Just desolder (or crunch) it, which would leave its series resistor leg floating (which is not a problem). The LED serves no other purpose other to show that the 3V3 supply is present.
What I plan to do is keep my first yellow board (with all its LEDs) as a test bed and then use either these or other configurations for actual projects once the code is proven to work.