This is the display i made for my alarm clock project. The first version was a 24x7 LED matrix but later changed the design for a four digits seven segment display. I decided to keep the drawings for the LED matrix and named it model A and Model B for the segment display.
The display is encapsulated in clear casting epoxy and is 5 inches wide by 2 1/4 inches high by 1 inch thick.
I was new to silicon molds and casting epoxy, so there was definitely a learning curve. I was unable to avoid the micro bubbles problem entirely. There are a few, but I can live with it, it’s not that bad. The assembly of each digits PCB, making the segments diffuser, gluing them, etc. takes a very long time. I did not want to start all over because of a few bubbles.
I wrote a python library for remotely controlling an Array 364x series bench power supply. These PSU are re-branded under many names (Circuit specialist, Array, 3Com). It is likely they all have the same firmware, so it should be compatible. I have tested it on my Circuit Specialist 3645A.
My previous electronics workbench was an old melamine office desk. It was not high enough to work comfortably on PCB assembly. I usually hand-solder small SMT components (0603, TSSOP, etc.) and I always ended up placing my PCBs on top of a box so I could see better what I was doing.
I looked online for a pre-built workbench, but I couldn’t find what I was looking for. Either it was too expensive or I didn’t like the design. I decided to build my own instead.
To be honest, woodworking isn’t one of my strongest skills, but in the end, I was quite satisfied with the results.
If you need to manage multiple servers, having to re-enter your password each time you want to establish an SSH connection can become tedious. There is a better way. It is possible to initiate an SSH connection by using a public/private key pair instead. The main advantage is that you can use this key on multiple accounts and only need to remember the pass-phrase of your key.
These are the delay subroutines i use in my PIC projects. It was written for the PIC16 family but should be compatible with the 18F instruction set as well.
The simplest way to produce delay is to write a subroutine that waste instructions cycles for the desired amount of time. This method should not be used for application that require a high level of precision since the delay subroutine may be halted by interrupts. The delay is offset by the time it takes to execute the interrupt service routine. For short delays however, this should not be a problem.
I installed a LED strip in my a/v rack to make it easier to see when I’m working on it. My plan was to buy white LEDs but it turned out to be cheaper to get RGB strips of the length I needed where I bought them. The kit comes with a controller and a remote control which allows you to set the intensity and change colors.