Somewhat of a novice here. I have built things with Arduino's before and they worked however, this one has me stumped. I have watched many you tube videos and finally settled on guidance from Electronics Demon https://youtu.be/JqBGBm2iza8 circuit.PDF (140.1 KB). There is an known error, Pin 1 goes to Ard 8 not 13.
. I am also taking advice from instructables Led-Cube-8x8x8/ and the 72 steps, this forum, and many other sources also.
I am using 1 anode 74HC595 register, and 8 cathode 74HC595 registers. I have a pre-made PCB board that I bought from jlcpcb.com using his Gerber file. I have spent literally hours soldering these LEDs and fashioning the cube only to be stuck at the very end of the project.
My problem is that I cannot make any patterns in these LEDs they are on constantly. If I take out some of the leads from the Arduino, I can make it flash in sort of a random pattern yet from one side to the other 1 second.
I read somewhere that this might be because of low power, and not to power the Arduino and the LEDs from the 5V from the Arduino. Yet, when I separate the power supplies, I still get no animation.
I am frustrated to no end. I will trade my extra three PCB boards for successful help in making this work. Unfortunately, I cannot upload items to this post for I am newbie.
I have a small video but I can't figure out how to post here. To get it to do any animation at all, I am manually touching the leads coming from the PCB and registers. sketch_jan03a.ino (11.8 KB)
The power supply's will need common grounds meaning you need the Negatives connected together.
That random pattern you describe could be the 'Rain' effect which is the 1st effect in the code.
The base of the transistors are all connected directly to the shift register. This will cause excessive current to be drawn from the shift register exceeding the maximum permitted current drawn from it. This will shorten the time before the shift register fails.
There are no decoupling capacitors at all in the whole of the circuit! This will cause very erratic behaviour. I know you will say but it works, but only by a fluke. Any slight change like a change in manufacturer of the ICs, or a change in location to one with more electromagnetic interference will cause problems.
I have put a note to that effect on the GitHub issues page, but I don't expect much response.
I would remove the ICs U2 to U8, so that only layer 1 is being powered. This will reduce the effects of having no supply decoupling on the shift registers.
To preset the effect you are looking at then change the start of the loop function to this.
void loop() {
randomTimer++;
if (digitalRead(BTN) == LOW) {
clearCube();
loading = true;
timer = 0;
currentEffect = 5; // change this number to the effect you want to see to debug.
/*if (currentEffect == TOTAL) {
currentEffect = 0;
}
*/
randomSeed(randomTimer);
randomTimer = 0;
delay(500);
}
See if the bottom layer behaves like you would expect.
That implies that you have a missing wire somewhere. Is there one side of the LEDs that you have to touch or is it both?
I have connected the ground on the Arduino and the negative pin on the PCB to the negative on the power supply. The USB powers the Arduino and a 5v 2A (supposed) separate ps powers the PCB.
to add clarification, there is block J1 on the PCB, that connects to the Arduino 1 -- 8, 2 --10, 3 -- 11,
4 -- 13. If I pull out 8, everything goes out. Put 8 in, take out 10, 11, and these I can touch and "sometimes" get a small pattern. 13 is suppose to be a "clock" timer I suppose to regulate the patterns, but since no patterns, can't see its function.
chr who built the instructables 8x8x8 cube you linked has a circuit diagram, ( Step 30: Build the Controller: Layout ) with the decoupling caps, ' 1uF ' between VCC & GND of the IC's
D8- connects to Ground/Reset
D10-connects to ST_CP. Storage Reg Clock In. Latch Pin
D11-connects to DS. Data Input
D13-connects to Shift Reg Clock In
Taking 8 out should have no effect. You connect 8 to ground to reset the Arduino...smells like a short somewhere
Yes but the 'chr' circuit diagram shows where to use decoupling caps on the ICs. You posted earlier you didn't know where to add decoupling caps.
I have an 8x8x8 led matrix soldered up and ready to go and I'm bread boarding your circuit for testing. The code compiled without complaint so that is a good 1st sign.
I took the button off of the board (no connection to anything) and pulled the pin out of J1 - 1 - 8 and get no LEDs on in the cube. I put it this lead back in (even with no button soldered), and with the code you placed and removing all ICs except 8, one steady on side of the cube.
I did not use the 'chr' circuit diagram. i used circuit.pdf posted above in entry 15 that did not list requirements for decoupling caps. I can add them, but I only have the PCB above and not the exact one that 'chr' shows or diagrams.
A decoupling capacitor - 0.1 uF, rated 10VDC or greater - should be wired directly from the ground pin of each shift register to the power pin of the same shift register. Can be soldered directly on the back of the circuit board, then hot-glued for stability.
C
Thanks, I will try this. Because i a relative novice, what will these capacitors do exactly? Also, will underpowering the unit cause the overall issue?
