I finally got the 74HC595 chips and decided to do a dry run on a breadboard. I used the schematic I made earlier with Fritzing and just rebuilt it, with a couple of LEDs on every chip. I used the code from this blog as a base and it worked on the first try. Now I have to adapt this code for my purposes.
Don’t panic, the test setup looks worse than it is 🙂
I started my second try on the front plate. Printing directly on the card board didn’t work out that well, so this time I printed it mirror inverted on a DIN A3 paper (the same size as the card board) and used spray glue to attach it to the card board. Then I used a crafting knife to cut out the characters, as before. This turns out to work pretty well, I guess the paper gives the card board even a little more stability.
Nevertheless this is a hell of work, the next time I’m doing something like this I have to come up with a better Idea for the front plate.
This is a summary of some thoughts I had on connecting the LEDs to the Arduino. When I read about charlieplexing I was amazed how many LEDs I could control with so few pins on the Arduino. Then I realized the downside of this technique: Essentially I can only light a single LED at a given time. Sure, there are a couple that can be lit simultaneously when they don’t share any pins, but setting those up would be a nightmare. So I started to group the words. Which words have to be lit when? Continue reading Thoughts on connecting the LEDs
I managed to attach the DCF77-Receiver to my Arduino and found a source code that works with it and reads the correct time as well as the correct date. Too bad I’m not going to use the date part.
Continue reading Reading the DCF signal