ESP8266 Community Forum

- Wed Apr 06, 2016 2:35 pm #44997

I made my circuit on stripboard, used a very low drain LDO Voltage Reg (MCP1700-3302E) a 10uF cap on the 3.3v output, a 120ohm resistor on the wake up circuit. I've used two GPIO pins - one to power up the DHT22 and the other to read it. This has now been running off an 18650 Li-ION battery for 24 hours and wakeup/deep sleep cycles of 10 minutes. All seems to be good so far.

Hi, I'm working on the same topic here in Switzerland. ESP201 with DHT22 and 18650 Battery. Currently I'm using a NodeMCU board for the SW development. I send the data using TCP with static IP to a node-red installation on a RasPi. I got UDP working too, wich is even faster and saves on battery energy. Would you be so kind to post the wiring of your module?
Thanks,
Urs.
BTW: node-red with TCP input works nicely, the UDP input is not working yet. aarrgh

- Tue Apr 12, 2016 3:01 pm #45381

Hello, I must admit that I had no problems at all with the Huzzah Breakout, it never hangs.
Only Feather Huzzah hangs in my case.

One question, regarding Huzzah and battery duration:
- during deep sleep I noticed that the red led is slightly dim, you have to turn off all lights to notice it (I noticed it by chance)
I added a pullup resistor to GPIO0 and now it's compeltely dark. Testing now the enhanced battery duration.
- with LDO PIN I can disable the regulator. Since I have nothing connected to the huzzah, if I turn it off do I save some battery?

I ask because I'm unable to measure uA with my multimeter, when I set it to uA the Huzzah doesn't turn on. Also, the minimum measurable is 200 uA.

Initially my Huzzah work fine. After running flawlessly for more than three months reading a DHT22 and sending data to Blink it started freezing up out of the blue. At first I suspected the DHT22 but removing it and putting a simple deep-sleep sketch in improved the time till it freezes, but the problem still remains. Battery life management is super important but having a stable reliable platform is critical, hopefully someone here or Espressif can figure this out.

- Fri Jan 27, 2017 3:28 pm #61633

Hello,

Yes, sounds very much like ESP.deepSleep() is what you need to use. I am using the same for my temp/humidity sensors which connect and report every 15mins. While awake, the circuits draw around 75mA, but in deep sleep they draw less than 200uA which dramatically increases battery life (i am currently using 3 x AA or AAA NiMH cells but am also considering using Li-ion).

To wake from deep sleep, you need to connect the correct GPIO line to RST. I use WeMos D1-mini rather than the Huzzah boards, but the principle is the same. Using a wire to connect the two pins prevents uploading a sketch while the board is in deep sleep, so rather than a wire connection, i use a 500R~1K resistor instead, which allows sketch upload reset the board.

You could put all your code in setup() or some in loop() if you like, it really doesn't matter. But because of the use of deepsleep(), loop() will probably only ever run once before the board is reset, depending how you write your code. Its true for my sensors.

I have seen example code which allows multiple SSID/passwords to be used. I'll try to find it again and post a link here.

For entering SSID/passwords, can you connect the unit to a laptop via a USB cable? The unit could request & receive that data via serial. Or you could re-upload the sketch with the latest passwords hard-coded in. Another possibility is that you could store the list of required SSID/passwords in a file on the server, which the unit could download regularly. You might have to think about the security concerns of storing those passwords on a server.

Paul

Paul,
Would you be able to post up your code for your weather stuff? I am working a project now and would like to see how you have yours setup.