The seventh part of this series is all about the sensor board. It hosts the position sensor and four fill sensors. Speaking of sensors sounds complex, but these are just pairs of IR-LEDs and phototransistors. All design files for the board are in the GitHub repository and if you missed one of the previous parts,…
Adding a Light Barrier using Epoxy
As you read in my last post about the pet-feeding device project, there was an issue with the fill sensors. The lines from the 3d-print transferred the light directly to the sensor and made a useful measurement impossible. One of the solution to this problem is a small gap between the LED and the sensor….
Unexpected Fill Sensor Problems
While testing the sensor panel, I ran into unexpected problems, requiring a small redesign. First, let me explain the simple working principle of the fill sensor circuit and what I tested so far. The Circuit The circuit for the fill sensors is straight forward. There are four input lines and one analogue output line. If…
Project Update: New Stepper Motor Driver
In this short update, I will talk about the improved stepper driver for the pet-feeder device. While working on the sensor board, to see if the fill sensors work as expected, it also involved using the stepper motor. Here, I realised, the combination of stepper motor and driver I worked with is way too noisy…
MicroMaTch Connector to Breadboard in 5 Minutes
Ordering a board with perfect spaced pads to use an SMD connector takes a few days of patience unless you live near a PCB prototyping facility. With striped prototyping boards, you can stick a MircoMaTch or similar connector into your breadboard in under five minutes. 😉 First cut a small piece from the prototype board….
Pet Feeder – Position Sensor Tests
I worked on testing the sensor board. The first tests I did were about the position sensor. Recap Let me recap the design of the position sensor in the device: The turntable has five position slots, marked red in the following illustration. Behind this slots, there is a small excavation, reflecting the light from the…
How to Assemble the MicroMaTch Connectors with a Hammer
I mentioned in one of my posts how to assemble the MicroMaTch connectors using a hammer, but never explained the rather simple method in detail. So I made a short video, explaining the exact technique I use. If you have any questions, missed information, or simply want to provide feedback, feel free to comment below…
Pet Feeder Update
A short update about the progress with the sensor panel and photos of the final input panel board. I assembled the new boards and are testing the sensors. As soon as all tests are done, and I am happy with the results and the board’s design, I will write the next part. These are 940nm…
19″ Rack Fan Controller [1/2]
When I migrated several servers into a new server rack, I put my Arduino Uno based fan controller into a new enclosure. Not a great solution, but good recycling of this existing project and way better than the built-in, on/off temperature controller. Now, when the rack’s space got low, I had to find a better…
Art Like Boards from OSHpark
For the pet feeding device, I ordered boards from OSHpark with the “After Dark” style. This colour combination of the black substrate with the copper and transparent solder mask is just beautiful. I made this post just in case you did not see the pictures on Twitter or like to see them with a better…