This was the second kit that I made for my university's electrical engineering club. It was also the first four layer board I made!
What is this?
This is a clock with a digital and analogue display. The novel aspect to this project is that there's no microcontroller; we've gone back in time and only used 74-series logic ICs and a 555 timer to operate the whole thing.
A user can choose to have both the analogue displays active, just one, or neither. The time will continue incrementing whether the displays are on or off. This allows for low power usage, or if you simply don't want the display on at some point. These options are controlled by shifting some jumper shunts on the back of the PCB.
The time is set by the four buttons on the front. One increments the hours place, one increments the tens of minutes place, once increments the ones of minutes place, and the last one toggles the PM light in the top right.
There's the option for USB power, which may be convenient if this is used on a desk, next to a computer. The USB power will override the battery power when plugged in.
With this kit, I wanted to allow for a bit more customisation after people had built it. The remote was all done and dusted when students finished, but there's a bit more to this clock. I broke out the pins for all of the time places in BCD (binary-coded decimal), so if a user wanted to make an alarm based on this clock, they can add on a little circuit.
Additionally, as shown in the video, there's a jumper so that a user can provide their own clock source. They can add a real-time clock to improve the accuracy (the 555 leaves a bit to be desired), or they can plug in a function generator and ramp it up for something cool to look at!
This was also sold by the UQ Electrically Based Engineering Student Society for students to build.
Why did I do this?
I wanted to make another kit for electrical engineering students, to help them improve their skills. This kit was meant to be a bit more advanced than the TV learning remote. As a result, it considered basically all surface mount components, to improve soldering skills, and they could learn more by seeing the schematics and the design files for a four layer board.
I think that it's integral to electrical engineering to get your hands dirty and build things to see the reality of the concepts that have been studied. Through design and construction, everyone can see that they can create whatever they can imagine!
It also ended up teaching me about small-medium scale production of electronics, which was valuable.
Here are all the files that you'll need to be able to make the project yourself. The guide is a bit lacking because I was very busy at the time. Hopefully I'll get around to writing a proper one in the future.
This project was completed in mid to late 2016.
I was pressed for time with this project, designing it in the middle of my final year of electrical engineering. It would've been nice to do something cooler, or add more features to this, but there simply was not time. I'm very happy that I managed to get it out and that some of my fellow students got to build their own!
Through this project, I learnt more about and used skills involving:
-Laser-cut case design
-Small-medium scale production of electronics and sourcing large amounts of appropriate components for good prices