Raspberry Pi 3 B+ Blinkt no longer working


#1

Hi,

Got a RaspPi 3 B+ for my birthday and I thought I would install the blinkt hat.
All fine and dandy used it to tell me the CPU load while I was running PMS on it.

The other day i decided to remove it (very, very gently) so i could do some other bits with a breadboad.

I went to try out a blinkt script but upon connecting the pi to the breaboard and then the blintk to the breadboard it does not work anymore.

I tried it with my Pi Zero just swapping the GPIO pins for the Pi 3 for the ones on the PI Zero and that works fine.

However when I connect it back onto the Pi 3 its not working. I have doubled checked the gpio pins to make sure they are the correct ones 5v, GND, 23 and 24.

Ive checked the voltage of the PI 3 and its the same as the Pi Zero (5v) and I do not know how to test the GPIO 23/24 pins.

Im at a loss of what to do next, anyone got any ideas?

Thanks! :D


#2

What were you doing on the bread board in between it working and not working?
I’d run the one line installer again, if you haven’t already.


#3

Nothing, with the RPi 3, I took off the blinkt hat.
I tried the breadboard with the pi zero first with blinkt so make sure the script working but upon connecting the jumper wires to the Pi 3 it was not working.

I got a new blank sd card and installed stretch lite, updated raspbian and then ran " curl -sS https://get.pimoroni.com/blinkt | bash"

Still nothing, but it still works on the Pi Zero, thats why I think the GPIO pins 23 and 24 or even more are not working.


#4

Ok, was just ruling out another installer or other software config changes mucking things up.
One way to test those GPIO are to hook up an LED and resistor.
https://learn.pimoroni.com/tutorial/hacks/resistor-led

A picture of your setup may also help, how you have the breadboard connected etc.


#5

WIll uplaod a picture shortly, phone decided to die as I was about to take a picture.

Basic led works fine connected the breadboard to the 5v and gnd pins on the pi 3.


#6

If you connect the Blinkt directly to the Pi 3B does it work?


#7

No, it does not.

Thats why im thinking somehow the GPIO pins 23 and 24 have disconnected somehow

Edit: Added a pic of the Pi 3 with the led setup.


#8

Heres a pic of the blinkt set up with the pi zero and the script running.


#9

Any a picture fo the blinkt setup with the Pi 3, same setup with the script running.

Sorry for the multple posts, cant upload more than 1 pic per post :(


#10

Ok, take the LED + Resistor and connect one end to the GPIO, then see if you can turn it on with that GPIO.
Something like this, https://thepihut.com/blogs/raspberry-pi-tutorials/27968772-turning-on-an-led-with-your-raspberry-pis-gpio-pins
I should have read all the way through the link I posted earlier, I thought it did what I just posted, but it didn’t.


#11

Okay, that works fine. Both the GPIO 23 and 24 pins turned the led on and off again. (Can post pics if needed)


#12

Are you swapping the same SD card between the Pi 3B+ and Pi Zero? It’s possible a software problem could have crept in.


#13

I will do it now to double check. But the SD card in the pi zro was a fresh one I set up last night on the Pi3.


#14

Nope, swapped the card that was in the Pi0 and put it in the Pi3 and it did not work.


#15

Ok, just to recap what happened.
Blinkt worked directly connected to Pi 3B+
Also works on Pi Zero.
But now won’t work on Pi3B+ even if connected directly to GPIO.
GPIO pins work to turn LED on off, in basic on or off, high or low mode.

@gadgetoid, those pins are setup as clock etc though aren’t they? Could that communication be what’s messed up?

@soulstrider123 has anything changed since it first worked? Are you still using the same power supply etc?


#16

Yeah thats what happened so far

Im still using the same power supplyon both, the one that came with the 3 B+ starter kit.


#17

Ok, I’m all out of idea’s at this point? Something is defiantly messed up with the Pi 3B+, I have no idea what though? If it was the breadboard and jumpers, it should still work when connected right to the GPIO header. Jumper cables can some times mess with digital signals. Stray capacitance etc, interface.


#18

Yeah, but since im using the same wires between the pi3 and the zero surely it would be the same on both.

At least i know the pins 23 and 24 are working…kinda? since they can control the led


#19

Yeah, it works via jumpers with the Pi Zero, so its not that. And those GPIO can turn the LED on so they aren’t blown. Not totally anyway. Hopefully gadgetoid has an idea?


#20

Re-reading over all the steps herein, I can’t explain it!

The Blinkt! uses “bitbanged” IO, which means the GPIO pins are toggled independently by program code in much the same way as you might toggle an LED. Just a little faster!

It could be that they’re damaged in such a way that they don’t produce a reliable high-speed signal, even with the pins being toggled on and off, but there’s no easy way to test that if you don’t have an oscilloscope handy.

It might be worth grabbing the latest Blinkt! library since I’ve fixed some timing issues that could explain why a Pi 3B+ doesn’t work while a Zero does. On your Pi 3:

sudo pip install blinkt

And see what happens.