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⬅️ Previous capture (2021-12-17)
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I ordered another inexpensive DIY kit, this time from EQKIT through Amazon.
- clock/alarm/timer/stopwatch
- three buttons
- 6-digit 7-segment display
- runs off of 9V power (7V to 12V)
- driven by an ATMEL AT89C2051 with preloaded firmware
- single layer PCB with THT only
Here are some photos in various stages of assembly:
EQKIT clock partially assembled
EQKIT clock assembled (dark photo)
It took me about 1.5 hours to assemble the kit, most of which was placing the components and soldering. It was easy work — only a beginner would find the soldering work to be challenging.
- All through-hole, good for beginners
- Pads are all large and on the backside, good for beginners
- The AT89C2051 is mounted on a socket, so you could take it out and replace it with another one you had programmed yourself. I believe these are programmable with avrdude. Maybe you could reprogram the chip they sent, but they might have burnt the fuses for that.
- The simple design is easy to study and learn from.
- The end product has a decent amount of functionality to play around with. You could carry one around with you on trips, and it would be useful, but the alarm sound is not especially soothing, if that matters to you.
The main problem is the horrible ESL in the instruction sheet. Without actually counting, I'd guess about two or three mistakes per sentence. Fortunately, that doesn't really matter for reading the schematic or the components list. But the instructions on how to use the clock, etc. are hard to understand, which is problematic because the controls are not intuitive.
