ESP8266 Community Forum

- Tue Jun 02, 2015 5:57 pm #19290 Before i get abuse and banned off the site for my ignorance, can i just say i'm an ESp8266 vigin,and probably just need pointing in the right direction or a bit of educating

ok here goes

Am I correct in thinking that the ESP8266 is only really of use to send info such as temp sensors to the internet or can it
1. send data to other devices on the local network
2, Receive data from other devices
3. can 2 esp's comunicate between each other

going off on a tangent regarding power requirements.
I built a temp sensor that sends data to THINGSPEAK.COM using a DHT11, I was hoping to make a portable device using 2 x AA batteries, however the batteries run flat within a couple of hours and 2 x AA isnt enough to run the DHT11. Would 4 x aa blow the ESP8266 and any ideas on how to get more bttery life

Thanks in advance
Steve

- Tue Jun 02, 2015 7:27 pm #19291 Actually think of the ESP8266 as any other microntroller that just happens to have built-in WiFi capabilities. With the right program you can do just about anything, in reason, and I don't see anything on your list that couldn't be achieved with the right code.

As far as power consumption and using batteries, there are many posts about this. There are different sleep modes that the ESP8266 can run under and from your initial test results it sounds like none of them were used. The first thing you need to do is to implement sleep modes.

As far as power source goes there are multiple different ways to do this. This has been discussed so many times I think I should design a board for everyone so we can just point to that for reference.

To answer your question, no 4 x AA batteries can't be used in you wire them in series and provide an initial 6V. You could do 2 x (2 x AA) which would double your run time but this is far from efficient since you only start at 3.0V and will stop being effective once the voltage goes below that operating voltage.

I designed the module discussed in this thread http://www.esp8266.com/viewtopic.php?f=13&t=3269 but that's a little fancier than what you're after I think.

- Fri Jun 05, 2015 1:34 am #19513 Thanks for the reply very helpfull

Steve

- Fri Jun 05, 2015 4:11 am #19528 Deepsleep is done by putting a small cap across reset and XPD which is GPIO16 on the ESP8266-ESP12.

The function is
const int sleepTimeS = 20;// Time to sleep (in seconds):
ESP.deepSleep(sleepTimeS * 1000000);
This will stop it for 20 seconds and the program will start from the top again.

If you put a direct connection across instead of a cap it just keeps reseting

On the power thing the datasheet in the wiki above says the chip is good for 25% of 3.6 V which I take to mean it keeps operating down to .9 of a volt input. Note however that there is supposed to be a 450 mA pulse going out each 100 msecs . Don't quote me on that I'll try to find the source post

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG