• Correct me if I'm wrong

    rasmusviil0 • 06/15/2023 at 13:30 • 0 comments

    So all i've managed to finish is schematic for the PBC and not much more.

    I'll add a pdf of it to the files and would love for some feedback.

    the bigest source of uncertanty I have is in the way i am getting a negative votage. Firstly in the method itself more specificaly in the values for capacitors and resistors there. I managed to convinve myself that R66 MIGHT be needed but don't know if that is true. Pretty much all the values for the componenst there were taken from where the sun doesn't shine so please enlighten me.

  • This got more attention than i thought

    rasmusviil0 • 05/18/2023 at 12:20 • 0 comments

    ... I mean I hoped this would be the response but i didn't think it would actually happen. A short article the project but there really isn't more to say https://hackaday.com/?p=587271 and also talked about on the podcast https://hackaday.com/?p=588642 (16 minutes in for 2 minutes) complete with messing up my name thus giving me a new name. Thank you.

    Special thanks to Kuba Sunderland-Ober who gave great suggestions in the comments. In the long run i will be trying to implement the 2 color LED and adjustable reference points but for now i will try to

    a) control LED current and

    b) turn it into a PCB

    so. 

    Current control

    right now the setup for one led looks like this.This simply will not do. An alternative to this was pitched with a separate voltage source for the LEDs from the OpAmps and a transistor but i asked around an got this The OpAmp has enough oomph to supply the current.

    The PCB

    I'm using KiCad for this. Nothing interesting to show jet but i'll talk about some things i'm thinking about.

    • connection to the breadboard

    my last method was...unreliable. I am considering a spring loaded connector that feels like it could get pricey but i am not clever enough with mechanics to come up with an alternative so i might have to bite the bullet.

    • power

    last time it was a LiPo battery connector but needed to be driven from a controllable power supply because i added it last minute. This time i'm thinking USB connector.

    • negative voltage?

    for the opamps when the signal is close to 0V.

  • explanation(?) and result

    rasmusviil0 • 04/25/2023 at 10:29 • 0 comments

    Working principle

    sixty times in a row

    How did it turn out?

    in the end 10 lines out of 60 work properly. great success

  • Everything up to this point

    rasmusviil0 • 04/24/2023 at 18:46 • 0 comments

    I wanted to buy as few things as necessary for this project. This turned out to be

    • Transparent PLA
    • 2 perf boards (proto boards? whatever the correct name is)
    • 15x 4 OpAmps
    • a bunch of wire

    The project started when the contest was announced. I only recently discovered the podcast (and the rest of the community) and got a fire lit under my but.

    The first thing i did was print out the bread board. the first one had walls that were too thick so did it again with one layer walls, floor and roof. I cannibalized the metal insides from an existing breadboard.

    at first i wanted to use a micro controller but couldnt figure out how to get 60 adc readings.

    The opamps are to make sure the activity on the board isn't bothered by the lights. Opamps were purchased and soldered onto a perfboard with ones next to each other fliped so that the Vin and "ground" pins could be connected more easily. The + input of an opamp would become the signal input  and the output was connected to the - pin and would in future connect to an LED. Somehow.

    Connecting power was pretty easy. Though some hot glue needed to be used in a case of melted isolation.

    The following took place over the last 2-3 days.

    electrical sigval from the bradboard acieved by soldering a wire to the perfboard and making the dot of solder touch a line. this was unreliable. Alternative plan. solver a full line for each signal and sand them down to be level with each other. this works better. Now the breadboard is attached to a perfboad.

    Next up, stuff all the LEDs into the perfboard and breadboard. solder the - side of all of them together.next. solder a resistor to each positive LED leg. Then to each resistor a white wire. heatshrink the exposed bits. twist together matching led wire and line wire. stare in dread at the upcoming rats nest.
    now connect the two perfboards. This will look insane and take most of the day.

    solder in a battery connector and connect the ground between the LEDs and the OpAmps. some wires have fallen out but at this point your happy as long as the lights turn on

    realize you didn't test ANYTHING before.

    Test using 5V on power supply.

    It doesn't work. In fact it reaches the current limit. none of the leds are on.

    realize you messed up on the V+ and V- on the opamps.

    quick fix.

    test again. lights turn on

    celebrate and show off the rats nest to the world

    For the future

    For V2 alllll this stuff will move onto a PCB