ESP8266 Community Forum

- Sun Apr 30, 2017 7:12 pm #65433 Hello,

I apologise if this isn't the correct place for my question.

I am trying to learn electronics (I am a chartered software engineer and mechanical engineer but have very little electronics experience, which I am trying to rectify with this project).

I decided to fix my missing knowledge with a project that ended up using an ESP8266 board. I have managed to program and setup the project on a breadboard and am now trying to move to a standalone unit.

The basic project is to take the output of a PilotAware system (basically a Rasberry pi+hardware that streams data telling you where aircraft around you are) and display it. It is a sort of poor mans TCAS (traffic collision avoidance system) that normally costs tens of thousands and is only available in commercial/military aircraft but in this case only costs a hundred or so.

The original breadboard setup can be seen on

with the proof of concept version at
[youtube][/youtube]

The project involves using the basic board to received, decode and display data from server (as seen in the videos).

The point I'm at now is to work out a power supply that is as small as possible that can power the device and screen for at least an hour (ideally a few hours) but that is small and as light as possible. I could use three AA batteries but it seems that a rechargeable lipo would be smaller and fit better.

I'm considering a charger such as TP4056 and a lipo such as 3.7V 150mAh Lipo Battery which may be too small, but without testing it I have no idea how to work out if my setup would draw too much power (seems easier to try it and time it than to work it out )

I'm willing to teach myself how to do this but I've not found a site that shows the minimal requirements for a small and compact system with OLED that I can use.

So the question is ...
Given the small/lightweight requirements, what options do I have to power the oled and ESP8266 module (full power while on so no power saving modes etc while running) for at least 1-2 hours.

I'm happy to take pointers as to where to go to learn this stuff. i.e. how to work out/measure the power needed for the requirements I have or how to setup a rechargeable lipo system to power it.

I suspect I will also need a boost-buck converter as well but I am hoping someone will know of an all in one board I could use.

I just find myself suddenly stuck on how to move forward, with my lack of electronics knowledge most websites are either too advanced or too basic (i.e. they immediately start talking in acronyms I don't understand or are just explaining how to measure voltage on a multi meter).
I'm currently learning as I go (including the 3D printing side of things). Having to read a whole book on electronics would probably mean I would give up and do something else for a hobby (I have plenty on the go so distraction is always a problem ).

Any pointers, tips or links to relevant information would be appreciated.

If this post is in the wrong area or not valid feel free to delete it, although if you could let me know what I did wrong that would be appreciated. I was originally going to post in the hardware forum but thought it was better here.

Edited title to show hardware

Last edited by madmaveric on Mon Jul 08, 2019 2:25 am, edited 2 times in total.

- Mon May 01, 2017 7:53 am #65442 150mAH would be way too little. Assume 25ma for the display and 75mA for the ESP module. You need to measure the current that you would need but that might be a good starting point. For two hours you would need 200mA.

The MA rating for batteries usually is for a slow discharge, often over a 10 hour span. When you draw more current over a smaller time the mA capacity goes down.

Also the quality of the battery makes a difference. Cheap no name batteries do not usually live up to the seller's claims. You need to buy from a manufacture that provides a spec sheet , or do your own tests.

Power consumption is based on how many pixels you have lit up.

- Mon May 01, 2017 8:33 am #65443 Thanks for the reply, I was half expecting that the battery I linked might be a bit small.
I'll look for something with a larger capacity. Changing battery size isn't a big issue as I will build the case around it once I have got a viable capacity one (as it is mostly likely to be the biggest part).
It looks like I can use a TP4056 for charging but I'm still looking for a small voltage regulator to use as I can't just plug it into the lipo as the voltage will be too high when fully charged.

- Tue Nov 14, 2017 6:29 am #71837 LOL – spammed into replying to a 6 month old thread, silly me.

Hi, this looks like a great project - please keep us posted with the progress. The link below is one of the best I’ve come across, it doesn’t tend to be used much because of the cost but would be great for your project.

https://www.pololu.com/product/2122

With regard to the TP4056 boards commonly available there are two main types:
Single IC and two battery terminals – NO under voltage protection.
Three ICs and two battery terminals and two output terminals – this HAS under voltage protection.

If you google “TP4056” and go to images you should see what I mean. I would only ever use the ones with under voltage protection.

So if you go:
Charging voltage -> TP4056 module (battery terminals) -> LiPo cell.
TP4056 (output terminals) -> Buck Boost module -> Project.

That should just about do all you need.