It just happened too many times! I looked at the food or water bowl and it was empty.

For a long time I wanted to learn how to use Arduino, so I figured this will be a good starting project, I wanted to know, at a glance, how low are the food and water levels for my dog and especially when they are empty. I ended up with a two level green indicators and one red for empty for each bowl.

Hope you will like it and get some ideas for your next project.

Supplies

Arduino and electronics:

1. Arduino (or similar) board, I used Geekcreit® UNO R3 (https://us.banggood.com/Wholesale-Warehouse-UNO-R3...

2. Load Cell Sensor *2 (https://us.banggood.com/Wholesale-Warehouse-3pcs-H...

3. 1.27mm Pitch Ribbon Cable (https://www.banggood.com/5M-1_27mm-Pitch-Ribbon-Ca...

4. Heat Shrink Tubing (optional) (https://www.amazon.com/gp/product/B07PLHG6FY/ref=p...

Wooden Box:

plywood

Laminated sheet

Epoxy Resin (https://www.amazon.com/Epoxy-Resin-32-Tabletops-Co...

Tools:

Soldering tool

Computer

Hot glue gun

Jigsaw

Carving tool

Glue and screw

Step 1: Wooden Box

Not much to tell about this part. Just make sure you have the right dimensions for your bowls and your dog and that you can fit the sensors with a bit of a height to spear.

Since I had to program the correct weights for the food and water specifically, I decided to carve the correct place for each bowl.

I hot glued the LEDs after the paint and then used the epoxy. I did not "heal" the epoxy for the LEDs since I wanted the light to spread, that worked but I wish the light would have spread even more so you couldn't see the LED at all, just a green cube.

Step 2: Sensor and Code

The Load Cell I had where 1Kg, they are not very accurate (at list I couldn't make them) but good enough for this project.

I tried explaining as much as I could inside the code about how it works. fill free to ask in the comments any Q.

It took a lot of try and error until I figured out the correct way to work properly. For instance, how many scale measurements should I take to get a good wight reading and still not leg too much (used 10 by the end), or what would be a decent margin of wight for the scales, since I could not make them accurate to about +-2g.

Later on I added a reset button to the arduino so I wont have disconnect the USB every time I want to reset.

The lights work as so:

* "Moving" left to right when scale is ziro- the code expects no bowl inside the box

* One red light when empty bowl in place- weight of the bowl is embedded in the code.

* One and then two green lights whan bowl is full.

* All lights work when bowl is over full

* Red light blinks when scale not calibrated- this can happen if you restart with bowl in place, but you do have to pick it up to find out Or when the wight reading is too high.