LCD interfering with Keypad circuit

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marisun
 
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Joined: Tue Mar 25, 2014 5:38 pm

LCD interfering with Keypad circuit

Post by marisun »

My LCD seems to be causing interference with my keypad circuit that is hooked up to the same ardunio mega2560. The key pad is connected to D-22 through D-29 and our GND. Our LCD 16-pin Blue (no back-light) is connected to 2, 3, 4, 5, 11, 12, 5V and 2 GNDs. Both of the circuits work individually. however when we combine them they do not work. I have tried adding a BFC of 4700uF and 16V but that still does not change the weird errors we get in our program for the keypad. We know the same code works for the keypad alone so we know something with the code is not wrong. Any advise for getting rid of the interference?

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adafruit_support_mike
 
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Re: LCD interfering with Keypad circuit

Post by adafruit_support_mike »

Post your code and a photo of your hardware and we'll take a look.

It's both possible and common for two chunks of code that work independently to reveal problems when you put them together. Integration testing is a reliable source of obscure bugs.

marisun
 
Posts: 2
Joined: Tue Mar 25, 2014 5:38 pm

Re: LCD interfering with Keypad circuit

Post by marisun »

Attached is a zip file with the LabVIEW files for the programs individually and then one with them combined. As well, it is a bad picture but I have added two pictures of the hardware as well. Basically the wires are connected to terminal blocks that are connected to the arduino. Pin D_22 - D-29 are the pins 1-8 of the key pad. And the LCD pins are connected to the arduino as follows (LCD pin on left and ardunio pin on right)
1 GND and capacitor
2 5V and capacitor
3 empty
4 pin 12
5 GND
6 pin 11
7 empty
8 empty
9 empty
10 empty
11 pin 5
12 pin 4
13 pin 3
14 pin 2
15 empty
16 empty
Attachments
LCD and KEY pad.7z
Zip file with Labview program
(199.14 KiB) Downloaded 30 times

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adafruit_support_mike
 
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Joined: Thu Feb 11, 2010 2:51 pm

Re: LCD interfering with Keypad circuit

Post by adafruit_support_mike »

I'm afraid we don't have any in-house experience with LabView. It's common in professional labs, but is priced a bit above the average DIYer's range. As a side note, I don't have any compression utilities that will handle a .7z file.. all I got was a manual infinite loop of .7z unpacking to .cpgz, which in turn unpacked to .7z.

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