- Mon Sep 05, 2016 12:33 pm
#191555
Hello Sparkfun forum,
Working on an LED display that would sequence 320 LEDs
based on
http://bildr.org/2011/08/74hc595-breakout-arduino/
Pictorial of setup.
Was hoping turn on all 320 LEDs at once but found
out only 30 could be turned on at a time. So have limited the
LEDS on simultaneously by turning off the first LED
when the 31st is set HIGH.
Have daisy chained 25 of the Sparkfun BOB-10860 and
it works perfectly. But when the 26th is added the
26th BOB (74HC595 break out board) immediately
begins blinking erratically.
You Tube of 26th IC
https://youtu.be/xAc26amrLzI
Tried substituting the 25th BOB for the 26th.
No joy. Tried turning on fewer LEDS and several
other troubleshooting approaches with no luck.
Any idea why the daisy chain won't extend?
The article says "you have 1000 of these chained together".
Just trying to do 40.
Thanks.
Allen Pitts, Dallas Texas
PS Animated gif of half of the desired display.
Http://www.allenpitts.com/electronics/M ... 150626.gif
Working on an LED display that would sequence 320 LEDs
based on
http://bildr.org/2011/08/74hc595-breakout-arduino/
Pictorial of setup.
Was hoping turn on all 320 LEDs at once but found
out only 30 could be turned on at a time. So have limited the
LEDS on simultaneously by turning off the first LED
when the 31st is set HIGH.
Have daisy chained 25 of the Sparkfun BOB-10860 and
it works perfectly. But when the 26th is added the
26th BOB (74HC595 break out board) immediately
begins blinking erratically.
You Tube of 26th IC
https://youtu.be/xAc26amrLzI
Tried substituting the 25th BOB for the 26th.
No joy. Tried turning on fewer LEDS and several
other troubleshooting approaches with no luck.
Any idea why the daisy chain won't extend?
The article says "you have 1000 of these chained together".
Just trying to do 40.
Thanks.
Allen Pitts, Dallas Texas
PS Animated gif of half of the desired display.
Http://www.allenpitts.com/electronics/M ... 150626.gif
Last edited by AllenPitts on Tue Sep 06, 2016 12:33 pm, edited 2 times in total.