The object of your desire will not be able to resist this heart shaped kitsch-o-tron, lovingly hand-crafted on perfboard with a CD4017B decade counter and 555 astable. But you probably can't go wrong with flowers and chocolates as well. Just to be on the safe side. Kits now available from Tindie!
Blinky Heart Build
This project was not exactly an exercise in meticulous planning. I started out by getting together all the red LEDs I could find and soldering them on a perfboard in artistic fashion. I hadn't thought particularly hard about how to light them up.
When I counted up the LEDs and realized that I had used 10, I hunted around for a CD4017B decade counter (which has exactly that many outputs!) and a 555 timer chip. There were plenty of schematics on the internet to choose from and I shamelessly ripped one off, adapting it as I went. The diagram below approximates what I did or maybe should have done: in the event, I cut corners by leaving pin 4 on the 555 unconnected and omitting the 10 KΩ resistors.
The hard part was soldering the perfboard without the usual mess of jumper wires jumbled like spaghetti. To make things neater I used 0805 surface mount passives soldered on the back of the board. I strongly recommend mounting the chips in DIP sockets rather than hardwiring them. It was not an especially expert job but turned out fine, and not too hideous at the back.
Kits available now!
Make your own heart-shaped LED chaser without so much messing about. Stop by at the Magic Smoke Tindie store to order LED chaser kits, including all the necessary components and a custom-designed heart shaped PCB.
Materials
- 5 x 7 cm double sided prototyping board
- CD4017B decade counter/divider IC DIP16
- NE555 timer IC DIP8
- 8 pin DIP socket adapter (3, use 2 for CD4017B; optional)
- 5 mm red LEDs (10)
- SMD capacitors, 100 nF, 0805 (3)
- Tantalum capacitor, 1 uF (or SMD if you have it)
- Trimmer potentiometer, 200 KΩ, single turn
- SMD resistor, 1 KΩ, 0805
- SMD resistors, 10 KΩ, 0805 (2)
- 9 V battery clip
You May Also Need
- Electrical solder (rosin flux core, lead free)
- 26 AWG hook up wire
- Irwin self-adjusting wire stripper
- Hakko flush cutter
- Aoyue 936 soldering station
- Glue gun (for strain relief on battery clip leads)
4 comments:
I fixed the dodgy LED by the way! The connections were fine, but perhaps I overheated the LED while soldering it in.
Hi Tom,
My name is Allye, and I am contacting you on behalf of Texas Instruments. Congrats on this project, we hope your gal likes it just as much as candy or flowers for Valentine’s Day! We want to thank you for using TI products and for giving us a shout out by linking to our datasheet. We like how you creatively crafted this project, in fact, we like it so much, that we want to request your permission to share this content on our social channels and link back to your blog. We enjoy getting to highlight the creativity and ingenuity of our customers. Please feel free to comment back on your blog or reach me at afoster@ti.com with your response. Thanks again, Tom!
By all means Allye. I'm a big fan of TI.
Alejandro - I <3 it !
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