Hand Soldered LED Oscilloscope 

Those electronic notebooks from Forrest M. Mims III are still amazing.

Ask me anything :P I apologise for my mood at the end, I needed to draw a line and finish the video. If anyone has any tips on what I could try to fix the behavior, please share! I would even send some stickers and a 10mm LED for correct tips :D

I love those Forrest Mims books! I've built a bunch of projects from them over the years but never did get to the oscilloscope, though I did dream about doing it. This upscaled version is a fun project, I hope you work out the issue with the LEDs, it would make a great follow-up video!

once again nice work with the LEDs.

Awesome job Just Dave! :)

If you figure out the fix, please do post an update. Good luck!

Needs you to play Jerobeam Fenderson’s music through it

I like your idea and building that led X&Y oscilloscope is amazing. I am looking forward to see you final version of that project. I believe it will end a very nice working oscilloscope. I will suggest that you put different led color in the center of the display vertical and horizontal. Thank you and please tell me where I can download the schematic.

Hi Guys .. How to Fix you need to change on the LM 3915 IC from BAR to DOT Mode.. Check all common ground .

Nice

You need to add a resistor across the first led output

What is the name of the work book, Please.

Impressive to say the least. I hope you post the mods you did to make it x/y

You have way more patience than me Dave!

The Forrest M Mims notebooks got me started in electronics. I still recommend them to anyone else wanting to learn. They are fantastic books, and explain everything so well. It looks like maybe the LM chips don't like the current being driven into the output pins the opposite way. (and the pull-ups on the output pins of the other chips seem a bit too low value, and could be passing a fair bit of current through the open-collector drivers of those chips when there is no LED voltage drop there. The outputs only need to be logic-level to drive the inverter inputs, so I would try higher value pull-ups first, like say 2K2.) I guess there shouldn't be passing any current through the LEDs when the inverter outputs are low anyway, but I'm wondering if there might be some other weird effects there. Could maybe try some ULN2003 drivers as well... electronics.stackexchange.com/questions/221193/possible-to-drive-a-uln2003-driver-with-a-lm3914-bar-graph-display Although in theory, there should only be one column of LEDs driven at a time (based on the X input / inverters), maybe the inverters are still driving too many LEDs at once, or have some weird current paths through all of the LED junctions.

LM's are internally isolated, however when running a analog low power circuit, it is generally accepted that you keep your bus traces the same width and lengths, and keep your capacitors close and tight tolerance.

Hey you have GreatScott's pen, Lol

Ey den Typen kenne ich von der MakerFair in Hannover XD

Why?

-"Element 14, the electronic design community where you can connect and collaborate with top engineers from around the world" Where is the top engineer in this episode? Hello??