Best portable power options for an ATTiny85 based camera trigger

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1

Hi all

I've been working on a wireless camera (Canon) trigger which originally started life using the Arduino Uno. It's a project I've started which I hope I can develop into a neat controller for the camera for aid in timelapse photography, trigger based shutter release, among other things.

But for testing purposes at the moment I'm using only an IR LED which I am operating every 3 seconds.

Early in the project I decided, I didn't really want to use up an entire Arduino Uno for my one project idea, and would rather shrink it all down a bit, then solder up the pieces when I'm done (I'm new to all of this)

After many headaches, and hours researching, I've got to the stage where it now works over an ATTiny85, provided it seems, I'm giving it 5V power from the Uno (Whilst connected up to the computer)

I've tried connecting a 9V battery to power and ground, but then it doesn't work. I've also tried a CR2032 (3V) button cell battery, but that too doesn't work - It lights up an LED just fine if I put it before the ATTiny85 in the circuit, but that's it. The IR LED (or normal LED I use for testing) doesn't seem to flash at the 3 second interval like it does while getting power from the Arduino.

I've tried browsing the internet for a solution, but most of the time I end up on a page full of terms and knowledge I haven't grasped yet. I guess my questions at their core are :

1: What's stopping the CR2032 battery from powering the ATTiny85, as it seems other projects use one of these

2: Would a regulator work (7805 5v) in conjunction with a 9v battery? I nearly brought some of these, but then see mention of caps (I guess capacitors?). I also frequently see people shun the 9V battery as an option so I guess I should use something different anyway

3: In my case, what is the best power options available to me - AA, AAA, do I have to keep 5V in mind or should the ATTiny85 and an IR LED run okay on different voltages? I really don't have a clue what I'm doing :blush:

I'd appreciate it if anyone could take the time to help me out, thanks

  • Christian
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You are essentially building this...

This has information about powering it and provides a schematic for the circuit...

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Thanks Coding Badly :slight_smile: From the second link I also found a good resource to learn from with regards to batteries - How Batteries Are Measured | All About Batteries | Adafruit Learning System

I'll be sure to read through these articles to get an understanding, they have lots of information on IR LED's too so that will be good to read.

In the second article you linked it mentions that coin cell batteries wont work at all, but I can't figure out the reason why? Because I've swapped out the IR LED for a basic blue LED for testing and it still doesn't seem to work on a CR2032 (So I'm guessing it's not the IR drawing too much power) - while numerous sources seem to have an ATTiny85 and LED working fine on a coin cell - Attiny85 driving RGB LED powered by 20mm coin cell - YouTube
I'll use the power setup they have in the TV remote, I'm just curious really as to what's stopping the coin cell from working.

While I'm here, thanks Coding Badly for that tiny tuner! Had to use it to set it up for 16mhz, worked a treat.

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I can't figure out the reason why?

Very likely because they cannot maintain a reasonable voltage level and deliver the necessary current.

a basic blue LED for testing and it still doesn't seem to work on a CR2032

Very likely because the battery does not meet the forward voltage of the LED.

While I'm here, thanks Coding Badly for that tiny tuner!

You are welcome.

Which version did you use?

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arduino-tiny-0100-0018 :slight_smile:

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an alkaline button cell is no good for ir but a lithium coin cell works fine as millions of chinese key chain remotes will attest. ive personally used them in over a dozen of my own ir projects. a couple things to keep in mind:

range is about 1/4 that of 5v supply so testing should start with rx/tx close. multi led and no resistor fixes this.

clock frequency of the t85 changes going from 5v to 3v. not much but if timing is on the edge it can fail. it is possible to choose a constant that works for both with safety margin on rc5 protocol.

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B2D235:
arduino-tiny-0100-0018 :slight_smile:

I was actually hoping to know the Tiny Tuner version (1 or 2). :wink: