I've assembled the quad alphanumeric display with i2c backpack, and am getting an issue with the lower right corner (both the bar and decimal point) not lighting up. I've checked solder joints, connections, chips and resistors and all seem to be good. I'm leaning to a bad decoder chip right now.
It's running off a 5v trinket, with the Vcc and Vi2c connected to the 5v output from the trinket
Any thoughts of what to check, or will I need an RMA for a bad chip?
Quad Alphanumeric Display issue
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- Franklin97355
- Posts: 23910
- Joined: Mon Apr 21, 2008 2:33 pm
Re: Quad Alphanumeric Display issue
Could you post clear pictures of both sides of your board showing any soldering you have done and the connections to it?
- jj3
- Posts: 5
- Joined: Wed May 22, 2013 10:26 pm
Re: Quad Alphanumeric Display issue
It's non-leaded solder, so a bit peaker than I'd like, but it's what I had on hand. Attached is both sides of the board:
- adafruit_support_mike
- Posts: 67446
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Quad Alphanumeric Display issue
It looks like you might have a couple of solder joints along the bottom of the photo that haven't wetted the pad completely.
Just to be sure, give any joint that isn't a nice cone a dab of flux and reheat it until it flows freely. If that doesn't help, we'll call it a bad chip.
Just to be sure, give any joint that isn't a nice cone a dab of flux and reheat it until it flows freely. If that doesn't help, we'll call it a bad chip.
- jj3
- Posts: 5
- Joined: Wed May 22, 2013 10:26 pm
Re: Quad Alphanumeric Display issue
I fluxed and ran through all the solder joints on the board, same issue.
- Franklin97355
- Posts: 23910
- Joined: Mon Apr 21, 2008 2:33 pm
Re: Quad Alphanumeric Display issue
Please email [email protected] with a link to this thread for a replacement
- danlee58
- Posts: 8
- Joined: Fri Oct 10, 2014 3:49 pm
Re: Quad Alphanumeric Display issue
I have 2 of these Quad Alphanumeric Displays. I am Writing to them over the I2C bus. I only have one unit on the bus, but have tried both with the same results. I get an Acknowledge when I Write to the unit from my Coridium SuperPro board, but I can't get any Segments to light on either board. The code was written in 'C'.
Can you post a copy of your I2C Address/Command/Data that you used to display the Zeros?
Can you post a copy of your I2C Address/Command/Data that you used to display the Zeros?
- jj3
- Posts: 5
- Joined: Wed May 22, 2013 10:26 pm
Re: Quad Alphanumeric Display issue
I slightly modified the example "quadalphanum_mini" in the examples from the Adafruit LED Backpack library.
The basic code would be:
The basic code would be:
Code: Select all
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
char *message = "**** 0000 ";
Adafruit_AlphaNum4 alpha4 = Adafruit_AlphaNum4();
void setup() {
alpha4.begin(0x70); // pass in the address
alpha4.clear();
alpha4.writeDisplay();
// send a message!
for (uint8_t i=0; i<strlen(message)-4; i++) {
alpha4.writeDigitAscii(0, message[i]);
alpha4.writeDigitAscii(1, message[i+1]);
alpha4.writeDigitAscii(2, message[i+2]);
alpha4.writeDigitAscii(3, message[i+3]);
alpha4.writeDisplay();
delay(800); //So you have time to verify all the little bits are glowing properly
}
- jj3
- Posts: 5
- Joined: Wed May 22, 2013 10:26 pm
Re: Quad Alphanumeric Display issue
Missed the ending }... apologies!
Please be positive and constructive with your questions and comments.