ESP8266 Community Forum

- Thu Nov 10, 2016 10:52 am #57933 Hello all,
I will be powering an ESP8266 from a lir2450 (3.6v 120mAh coin cell).
Only for say 30 seconds (with WIFI) and then deep sleeping and recharging after.

Any idea if it's possible to power a screen as well with the battery?
I figure a typical TFT or OLED is out of the question, but maybe the little Nokia 5510 screen or even the SHARP e-ink one Adafruit now sells (they're darn expensive though).

Love to hear your thoughts.

- Thu Nov 10, 2016 11:20 am #57934 LCD without backlight (led) is the lowest power option. Then it depends if you need a graphic display or if you can get away with character displays.

I like using character displays with a I2C adapter board. I will typically use a 20x4 display. There are 3 volt versions but not as cheap as the 5v. Nokia 5510 might be the best option.

- Thu Nov 10, 2016 11:26 am #57936 How interesting, thanks for the reply!
I hadn't even considered a non-graphical display, but I reckon a 20x4 char display might be enough!
I'll give the nokia a go as I have one lying around, but could you poss recommend a small 20x4 screen and I2C adapter? (I've not used them before)

- Thu Nov 10, 2016 1:14 pm #57940 http://www.newhavendisplay.com/lcd-character-c-2.html

That gives an overview of what is available on the character display side. If you don't want to use up valuable power then look at displays that are listed as reflective or trans-reflective.

I normally use displays found on Aliexpress because of the low cost and free shipping. But these are designed for 5v. I have step-up converters (to 5v) that will allow me to use lithium batteries. I normally use 18650 types, from laptop battery packs.

16x2 with adapter https://www.aliexpress.com/item/HX-6M20 ... 94389.html

20x4 https://www.aliexpress.com/item/Free-sh ... 32929.html

20x4 display with adapter https://www.aliexpress.com/item/LCD-Boa ... 30622.html

I2C adapter only https://www.aliexpress.com/item/Free-sh ... 25668.html

I like character displays because they are low software overhead. Their availability will be good and they are of good quality. Different display types like cheap TFT displays are not always available. I do use them but you never know if you will be able to buy them at a low price in the future.