I have designed a coin sorter that arranges different coins into separate containers for a project.
I would like to program my Uno to count the coins based on weight using load cells/strain gauges.
For easiness sake, I am currently just sticking to £1 and £2 coins. My plan is to compute when £50 in 1s and £100 in 2s are reached and possibly to display that on a small led/lcd screen. It's sort of an electronic piggy bank if you will.
If anybody has done this before I would really appreciate your help with putting me on the right track with the code etc
I have only been using my Arduino for a month and a half so any suggestions/tips would be very much appreciated.
Once you've physically separated the different denomination coins into separate hoppers, you can calculate the value in each hopper just by weighing the whole hopper. I assume that's what you're planning to do. I haven't done it myself, but it seems to be straight forward to canibalise a set of electronic kitchen scales, for example as described here, to reuse the load cell and use your Arduino to read it. In your case rather than just using Firmata you'd need to write a sketch to do the arithmetic to calculate the number of coins and their total value, and display that on an attached screen. Attaching a small screen to the Arduino is something else that's commonly done - you can even buy shields with a screen and pushbuttons etc.
PeterH:
Once you've physically separated the different ... buy shields with a screen and pushbuttons etc.
Hey Peter thanks!
You are correct with assuming my project scope: that's exactly what I would like to do.
That is a superb tutorial on the kitchen scale, however buying mini load cells may be cheaper than buying kitchen scales. The Firmata software is new to me and it seems nifty for my project. I need to have a look into it a bit more and suss it out.
I wont dismiss the kitchen scale idea just yet!
Is it tricky writing a sketch to translate voltage change/resistance change into weight/mass? I guess it is just a case of identifying the voltage for 1 coin and then using that as a base.
holmes4:
Each coin has a different size - the coins are routed by size, you have a sensor for each size. weight is not involved.
Mark
Thanks Mark.
The coins are arranged into separate containers by size. I planned on measuring the weight of the containers to identify how many coins were in each one.
Are you talking about a type of optical sensor that I could use?
Jamesas:
Is it tricky writing a sketch to translate voltage change/resistance change into weight/mass?
Not especially. If the sensor generates a voltage then you will read that via an analog input, and just do some simple arithmetic to convert the analog value to a weight. The exact conversion will depend on the sensor's characteristics but you will know (or be able to find) the sensor's calibration data and from there the code to convert a sensor reading to a weight is quite simple.
I'm not suggesting you use Firmata. The project I linked you to used it to get the data to a PC but I don't think that's what you want here. Just write a normal sketch to measure the weight and interface with whatever display, switches etc you design into your solution.
