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1  Using Arduino / Displays / HD61202/HD61203 Based GLCD on: May 07, 2013, 09:38:43 pm
I have gotten my hands on an old RAMCheck from 2000. I open it up to find it has a 486 CPU in it. But that's not what we are here for. It also had a nice 32X128 GLCD that has both an HD61202 and HD61203 controller chips on it.

There are 20 pins on this display and I have confirmed the following pins by probing the pins while the RAMCheck is running the display.
Pin1 = 5V
Pin2 = Gnd
Pin3 = Contrast Gnd
Pin18 = Contrast 7.5V (May be negative 7.5V needed but don't know how to get a negative voltage)
Pin19 = Backlight +5
Pin20 = Backlight Gnd

I cannot confirm any other pins. So i tried connecting it to my Arduino Nove using Pinout A as shown in the KS0108 Graphics LCD library Playground page. I've been through all the documentation on the page regarding the reset wire, switching pins 12 and 13 as the possible chip select pins. Even tried swapping the wires on pins 15 and 16. I have connect the contrast lines as suggested and even bypassed the Arduino's +5 and gnd and used a 9V battery with the pot to give the required 7.5V to the contrast pins. Even reversed the positive and negative leads.

Am i missing something here or does anyone have experience running this kind of display on the Arduino that can give some suggestions?
2  Using Arduino / Installation & Troubleshooting / Re: My win7 computer won't recognize my uno on: February 22, 2012, 12:19:25 pm
I was having the same issue. Win 7 doesn't have the drives for it so you will need to install them.
3  Using Arduino / General Electronics / Re: Connecting Arduino to a Casio Keyboard's buttons on: February 08, 2012, 08:18:10 pm
Doesn't look like my idea will work. I did some testing. If any of the pins as set high or brought high by a key press the keyboard sees that as additional button presses and things go a bit wonky. SO there is no way to get the ardino to read a key press without interfering with the keyboard. Oh well. now to find a new project.
4  Using Arduino / General Electronics / Re: Pretected Power Supply on: February 08, 2012, 06:43:54 pm
The 7812 is rather pointless and may actually prevent any power from reaching anything. The minimum Vin for the 7812 is 14.9V. So if the car is putting out less then that, then the rest of the power supply will not receive any voltage. Now the 7805 is rated for as much a 35VDC so you don't need to worry about keeping the voltage input steady. Thats what a voltage regulator is for. To take the higher and unstable voltage and output a fairly stable lower voltage. The 7805 will get pretty hot even at 12 V so you will want a heat spreader on it.

Depending on the VR you use for the 3.3V side you might be able to use the output of the 7805 for it. If you use an LM2937-3.3 then it can handle up to 26V so going straight from the car can be done. But you will want a heat spreader for both VRs. Its not like you will need a full on heat-sink with active cooling or anything.

Just look at most car chargers for cell phones. They take the full 12V in and output 5V without heating up too much. Open 1 up and see what they have. Could just use a hacked charger for the 5V side and a simple voltage divider to give you the 3.3 V needed.
5  Using Arduino / General Electronics / Connecting Arduino to a Casio Keyboard's buttons on: February 08, 2012, 06:24:14 pm
I am working on a project where i want to update my Casio Ca-110 Keyboard to have an LCD display to show what Tone and Beats are set. So i need the Arduino to interface with the Number buttons, Tone Select and Beat Select buttons. I have mapped out the buttons to find which pins are shared for all the buttons. The idea was to use the Keypad Library to program the Arduino. Problem is it doesn't want to work. After setting up the sketch i run it and connect a wire from one of the Row pins to one of the Column pins but the Arduino doesn't register the connection.

#include <Keypad.h>

const byte ROWS = 2; //four rows
const byte COLS = 6; //three columns
char keys[ROWS][COLS] = {
byte rowPins[ROWS] = {12, 13}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {11, 10, 9, 8, 7, 6}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup(){
void loop(){
  char key = keypad.getKey();
  if (key){

So i'm wondering if there is some other electronics on your typical key pad that i'm missing? If so will i even be able to implement this on an existing setup like the Keyboard? If i can't use the keypad library how would i go about connecting the buttons through 2 pins on the arduino so it can detect the button press, without having to set pins high or low for fear of messing with the keyboard recognizing the button push?

This all seemed so much simpler when i was planning it in my head.
6  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 08, 2012, 02:10:32 pm
Wow i didn't notice that before. I'll bet its creating a tab for the older IDEs and one for IDE 1.0. Somehow having 2 tabs may be messing with the compiler. Neither tab will compile.

I saved the sketch under a different name and it compiles as it should. Now i can go home tonight and get everything wired up and see if its even going to work for me. I not sure if there will be any problem if the Arduino is using a keypad that belongs to another device that is still using it. I'm trying to use the Arduino to pick up button presses on my Casio Keyboard so the Arduino can display which Tone or Beat i'm using on the Keyboard. Just hope there isn't any conflict due to the voltage on the buttons. But i'll save that for another thread once i've done some testing of my own.

Thanks all. 
7  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 08, 2012, 01:01:24 pm
Sitting in front of another Win7 PC and just installed the 1.0 IDE and downloaded the Keypad Library. I'm still getting the same problems. What am i missing here?

Has the last 2 years really made me forget this much about Arduino?
8  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 08, 2012, 09:51:48 am
Ok i'm at work right now and on a win7 system. I just downloaded the IDE and the Keypad Library. I put the library in the C:\Users\pilcherm\Documents\Arduino\libraries folder as it should be.

I have the current version of the library and see that it has the Arduino.h in it. But i still get the same errors. I've been trying this on 2 different PC now and will try a 3rd here in about an hour and a half. There must be something overly obvious i'm missing here. Or maybe there is a better keypad library i could be using.

I downloaded the library for Ladyada's motor shield to see if its just the Keypad library. Well the motor shield examples give me no problems. It's like the IDE doesn't like setting a const byte.
9  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 08, 2012, 08:32:21 am
It's this keypad library.

On win XP. It in the Arduino 1.0/library folder as it should be.

So the WProgram.h to Arduino.h needs to be changed in Keypad.h right?

Thanks for the help!
10  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 08, 2012, 07:13:51 am
I've done a fresh install of Arduino 1.0 and all the built in library examples work fine now. But i just added the Keypad library and none of the examples it has will compile. I get this list of errors.

CustomKeypad:48: error: redefinition of 'const byte ROWS'
CustomKeypad:11: error: 'const byte ROWS' previously defined here
CustomKeypad:49: error: redefinition of 'const byte COLS'
CustomKeypad:12: error: 'const byte COLS' previously defined here
CustomKeypad:51: error: redefinition of 'char hexaKeys [4][4]'
CustomKeypad:14: error: 'char hexaKeys [4][4]' previously defined here
CustomKeypad:57: error: redefinition of 'byte rowPins [4]'
CustomKeypad:20: error: 'byte rowPins [4]' previously defined here
CustomKeypad:58: error: redefinition of 'byte colPins [4]'
CustomKeypad:21: error: 'byte colPins [4]' previously defined here
CustomKeypad.cpp: In function 'void setup()':
CustomKeypad:63: error: redefinition of 'void setup()'
CustomKeypad:26: error: 'void setup()' previously defined here
CustomKeypad.cpp: In function 'void loop()':
CustomKeypad:67: error: redefinition of 'void loop()'
CustomKeypad:30: error: 'void loop()' previously defined here

Why won't any new libraries work?

11  Using Arduino / General Electronics / Re: Tutorial for keypad 16 buttons on: February 06, 2012, 02:24:36 pm
So you've read through the keypad tutorial? It does a pretty good job of outlining how you go about finding which pins go to which buttons in the matrix. Each keypad can be different so its good to probe the keypad and find exactly how the buttons connect to the pins.
12  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 06, 2012, 08:49:52 am
The Sketch i first tried to compile and upload is the Hello World example sketch from the LiquidCrystal Library. Nothing was changed in the sketch i just tried to compile it and it came back with all the errors i posted in the OP. I then tried other example sketches from the other Libraries that came with Arduino 1.0 and had the same issue. The Library folder has not been removed from the Arduino 1.0 folder. There may be some older libraries in there that i moved over from my Arduino .8 folder but all the library examples i've tried are from recent and up to date libraries.

I'll try a complete wipe of Arduino from my system and reinstall it when i get home. This has been very odd since its only those sketches that use libraries that won't compile. Others example sketches such as Blink load just fine.
13  Using Arduino / Programming Questions / Re: Trouble with any sketch that uses a library on: February 05, 2012, 03:20:23 pm
Thanks but that didn't change anything.

This is happening with any sketch i use that uses a library. Be it a sketch i made myself or one of the default example sketches that come with the various libraries.
14  Using Arduino / Programming Questions / Trouble with any sketch that uses a library on: February 05, 2012, 01:01:20 pm
It has been a couple of years since i was last on here or played around with an Arduino project. I recently broke out my Nove, downloaded Arduino 1.0 and went about familiarizing myself with everything. The project i'm working on will need a Keypad and LCD display. So i've been relearning how to connect my HD44780 display and uploading one of the example sketches from the LiquidCrystal Library. But when i go to compile the sketch Arduino 1.0 spits out a bunch of errors.

In file included from HelloWorld.cpp:39:
C:\Documents and Settings\Michael\My Documents\arduino-1.0\libraries\LiquidCrystal/LiquidCrystal.h:82: error: conflicting return type specified for 'virtual void LiquidCrystal::write(uint8_t)'
C:\Documents and Settings\Michael\My Documents\arduino-1.0\hardware\arduino\cores\arduino/Print.h:48: error:   overriding 'virtual size_t Print::write(uint8_t)'
HelloWorld:97: error: redefinition of 'LiquidCrystal lcd'
HelloWorld:41: error: 'LiquidCrystal lcd' previously declared here
HelloWorld.cpp: In function 'void setup()':
HelloWorld:99: error: redefinition of 'void setup()'
HelloWorld:43: error: 'void setup()' previously defined here
HelloWorld.cpp: In function 'void loop()':
HelloWorld:106: error: redefinition of 'void loop()'
HelloWorld:50: error: 'void loop()' previously defined here

I've even tried sketches i made a couple of years ago that use this library and get the same problem. It seems any sketch that involves a library is giving me problems with compiling. Any help would be much appreciated.
15  Forum 2005-2010 (read only) / Forum / Re: Suggestion - New forum for circuit schematics. on: February 27, 2010, 04:40:57 pm
Allot of the time this kind of this is in the hardware development side of exhibition side. If its not there its in links to there main writeup page for the project. Often on there own web page or on

But i can see the benefit of a one stop place for just parts lists and schematics. Easy to sort threw and find any projects that have already been done so you don't end up repeating someone's idea.
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