I'm working on a larger project that uses a keypad for input. Before I add it to my project I tested it separately to see if it worked. I followed this guide:
This is my setup:
Do you see anything wrong with this setup?
I don't get any information printed to my serial window when I press a button. Thanks, Mike
I didn't check every wire in the photos, but I can't see what's wrong.
Can you use a multimeter, and with the keyboard not attached to the Arduino. To see if pressing a key causes a combination of wires to connect ?
Can you add a serial print to the setup() function, so you know the serial communicaton is okay ?
Serial.println("Hello");
Those solder joints looks very suspicious!
Is the solder even contacting the pads below ? It almost looks like there is no pad underneath the solder, almost like someone ripped it clean off...
Please take a better picture from a different angle of this
// Per.
Zapro:
Those solder joints looks very suspicious!Is the solder even contacting the pads below ? It almost looks like there is no pad underneath the solder, almost like someone ripped it clean off...
Please take a better picture from a different angle of this
// Per.
I tried to be very careful when I was soldering, and I tried pulling on the wires connected to the keypad to see if they were lose, but they seemed to be very secure. Here are the pictures you requested.
If you touch pins 5 and 8 on the arduino, do you get an output?
Why are you using pull down resistors? Take them out.
HazardsMind:
If you touch pins 5 and 8 on the arduino, do you get an output?Why are you using pull down resistors? Take them out.
I resoldered all the connections so I'm just about 100% sure it's not my connections that are bad. I touched pins 5 and 8 but nothing happened. The reason I was using the resistors was because I was following this tutorial: http://bildr.org/2011/05/arduino-keypad/
You won't need external resistors or diodes because the library uses the internal pullup resistors and additonally ensures that all unused column pins are high-impedance
http://playground.arduino.cc//Code/Keypad
Also if you download the Keypad library, why not just use one of the other examples to test your keypad?
HazardsMind:
You won't need external resistors or diodes because the library uses the internal pullup resistors and additonally ensures that all unused column pins are high-impedance
Also if you download the Keypad library, why not just use one of the other examples to test your keypad?
I'm thinking it must be my arduino uno that's the problem. I tried the examples but none of them seem to work. I connected my multimeter to pins 2 and 3 and read -.005 volts and when I pressed button 1 the multimeter instantly went to zero volts. So do you think my arduino is bad?
mpick67:
HazardsMind:
You won't need external resistors or diodes because the library uses the internal pullup resistors and additonally ensures that all unused column pins are high-impedance
Also if you download the Keypad library, why not just use one of the other examples to test your keypad?
I'm thinking it must be my arduino uno that's the problem. I tried the examples but none of them seem to work. I connected my multimeter to pins 2 and 3 and read -.005 volts and when I pressed button 1 the multimeter instantly went to zero volts. So do you think my arduino is bad?
You want to be measuring resistance, not voltage.
I just went through and tested all of the pins on my arduino with a servo motor to check and see if my arduino was broken by chance. All the pins work (1-13). And my serial link is good. This is really aggravating. 
this silly keypad is holding up my entire project.
I think I now see what your problem is. I just tried to make my own keypad password, with a changeable master password and once I change the master, my '1' button does not work. Even in the serial monitor, it won't work. I don't understand what changed, but I think your having the same issue, however yours just wont work at all.
This is very strange.
Now if it was just the keypad, you should get a reading when you touch pins 5 and 8, but even then, nothing happened.
It must be a bug in the library.
I solved my problem, and I think I spotted yours. Your resistors, are they going to GND or V+?
