RGB LED Oscilloscope
using cheap eBay kits, some cheap eBay RGB LEDs to make an LED oscilloscope (inspired by Ted Yapos - LED Oscilloscope Mk. II)
I've recently bought this book:
https://www.amazon.com/Forrest-Mims-Engineers-Notebook/dp/1878707035 and in there featured is a basic LED oscilloscope with LM3914(/3915) and a 4017 [
http://www.cmos4000.com/cmos/4017.html]
There also was a conversation about doing an RGB version on
https://hackaday.io/project/19472-led-oscilloscope-mk-ii/log/52606-remaking-the-original - and I was hooked, of course!
RGB LED Oscilloscope | Mildly annoying results
2017-02-11 13:33:24
I should have tested it before, first the kit themself and then the forrest mims version. The matrix is all soldered up and the kits are soldered like I've interpreted it so far.
At this point I cant tell what I've captured there, I'm having my thumb on signal ground to produce some jitter.
Some thoughts
- I had to change the capacitor for the 555 to around 100nF, because I need a much faster scanning of the 4017
- no LEDs were used of all the kits (yay, rectangular LEDs!)
- resistors for the red LEDs of the LM3915 kit were "jumpered"
- my orange LEDs turn green when I slow down the scaling, which for me hints to too much current being drawn
- the bottom line seems to mirror the top line and everything is upside down from what I've expected
- using 50 orange LEDs from one bag and 50 orange LEDs from another doesn't mean you get 100 equally orange LEDs (I still have some green 3mm LEDs though, also diffused, better suited for this)
- meh
- meh
- meh, I need chocolate. Yes, you've read that right, I need beer
- I have to, but I don't want to "reverse engineer" the kit's schematics
https://cdn.hackaday.io/images/8119771486816309875.jpg
RGB LED Oscilloscope | Mildly annoying results
2017-02-11 13:33:24
I should have tested it before, first the kit themself and then the forrest mims version. The matrix is all soldered up and the kits are soldered like I've interpreted it so far.
At this point I cant tell what I've captured there, I'm having my thumb on signal ground to produce some jitter.
Some thoughts
- I had to change the capacitor for the 555 to around 100nF, because I need a much faster scanning of the 4017
- no LEDs were used of all the kits (yay, rectangular LEDs!)
- resistors for the red LEDs of the LM3915 kit were "jumpered"
- my orange LEDs turn green when I slow down the scaling, which for me hints to too much current being drawn
- the bottom line seems to mirror the top line and everything is upside down from what I've expected
- using 50 orange LEDs from one bag and 50 orange LEDs from another doesn't mean you get 100 equally orange LEDs (I still have some green 3mm LEDs though, also diffused, better suited for this)
- meh
- meh
- meh, I need chocolate. Yes, you've read that right, I need beer
- I have to, but I don't want to "reverse engineer" the kit's schematics
https://cdn.hackaday.io/images/8119771486816309875.jpg
RGB LED Oscilloscope | 3mm mono colored prototype
2017-02-10 12:19:27
Yesterday I thought I could 3D print a little LED holder to solder up a 3mm LED 10x10 matrix, where with that I could kit bash a mono prototype together - well, that escalated quickly. Out came the "blincotron". Since the front side looked a bit offset and boring, I've also added windows for the colorful backside of the pcbs to show. There are 2 potentiometer wholes and one for a switch, to manipulate "vertical gain", "horizontal sweep" and "freee running vs. triggered sweep". Still missing is a whole for the input signal (of course....) and a good spot for the 4011.
RGB LED Oscilloscope | 3mm mono colored prototype
2017-02-10 12:19:27
Yesterday I thought I could 3D print a little LED holder to solder up a 3mm LED 10x10 matrix, where with that I could kit bash a mono prototype together - well, that escalated quickly. Out came the "blincotron". Since the front side looked a bit offset and boring, I've also added windows for the colorful backside of the pcbs to show. There are 2 potentiometer wholes and one for a switch, to manipulate "vertical gain", "horizontal sweep" and "freee running vs. triggered sweep". Still missing is a whole for the input signal (of course....) and a good spot for the 4011.
RGB LED Oscilloscope | shopping time
2017-02-06 12:47:49
My favorite time of a project cycle!
parts | price | amount | total |
100pcs common anode CA RGB LEDs | 3.41 EUR | 1 | 3.41 EUR |
CD4017 NE555 LED chaser board | 1.15 EUR | 1 | 1.15 EUR |
LM3915 "funny" diy kit board | 1.50 EUR | 3 | 4.50 EUR |
Total | | | 9.06 EUR |
Thanks to current political events that makes: 9.73 USD
With a little creative air wiring this will make a lovely solder Sunday :)
RGB LED Oscilloscope | shopping time
2017-02-06 12:47:49
My favorite time of a project cycle!
parts | price | amount | total |
100pcs common anode CA RGB LEDs | 3.41 EUR | 1 | 3.41 EUR |
CD4017 NE555 LED chaser board | 1.15 EUR | 1 | 1.15 EUR |
LM3915 "funny" diy kit board | 1.50 EUR | 3 | 4.50 EUR |
Total | | | 9.06 EUR |
Thanks to current political events that makes: 9.73 USD
With a little creative air wiring this will make a lovely solder Sunday :)