While recalling the fun one could have with the project kits and parts found in the Radio Shack of the 1970s, I found a little board I made in 1978 (as usual stumbling across it while looking for something else). Every part on this thing came from Radio Shack. The IC is a National Semiconductor LM3914N, which is a 10-LED bar/dot display driver which at the Shack cost $2.49. Solderless breadboards were a new thing back then, with CSC (that is Continental Specialties Corp.) being the primary vendor at the time. Radio Shack offered the perma-proto board seen here for about $1.79. The LEDs were sold in packs of 2 for $0.79 and with the wire, switch and a few passive parts the entire project cost about $10. The short demo videos show the bargraph and dot display modes.
I went on to make a stereo VU meter later that summer, again all parts from Radio Shack:
And while it came with a data sheet, remember–this was Radio Shack–they had Forrest Mims notebooks. This exact circuit is used twice:
I went on to do more with the LM3915, such as build a 70-LED spectrum analyzer. However I will save that for another day. (read: I have to find it!)
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.