I think there are at least four problems in the above I2C code:

1. Matrix Orbital defines what they call an "8-bit address" which is the standard I2C address shifted left one position. This means that if the address is 0x50, it must be sent unshifted.

2. The I2C protocol calls for data to be sent ...

There are a few problems in the I2C.C code posted earlier. Here is a corrected version.

Russ

===========================================

/*
* Routines to drive a standard I2C bus.
*/


#include <stdio.h>
#include "\JKMicro\H\i2c.h"
#include "\JKMicro\H\Ports186.h"

#define SCL PORTA
#define ...

Miles,

No problem, glad to help.

It would be nice to have a facility to share files here.

Russ

================================
/*
* MOLCD.h
*
* Definitions for interfacing to the LCD.
*
*/

#ifndef MOLDC_h
#define MOLCD_h

#define DEFLCDADR 0x50

void LCDsetadr (int adr); /* Set the address of the LCD to be accessed */
void LCDwrite (int dat);
void LCDstr (char *dat);

int LCDread ...

Chester,

Well, there IS a way you can test to see if you have a MO display connected!

Use the output pins! Connect one or more of the output pins of the MO display to input pins of your microprocessor. Set the MO output pins, read from the processor to make sure you have the same bit pattern ...

Miles,

From the link you provided:

[/quote] Q: Do you use ACK? What do I do with it?

A: The idea of ACK is to indicate when the data has been received correctly. ACK does not indicate data incorrectly received. ACK simply "fails to acknowledge" when data is incorrectly received. Clearly, this is ...

Chester,

Hmmm. I'm at a loss. I haven't tried to read anything other than the keypad, and I don't use the "Poll Keypad" command. I just issue a read from the LCD and I get the characters.

I wonder if your problem has to do with timing. I read in another message that there is a problem with doing ...

Chester,

Are you able to read from other I2C devices? The protocol is rather particular, I found. I used the pseudo code from the site mentioned in the Matrix Orbital manual. I had trouble reading because I wasn't switching the SDA line to input. (Not mentioned in the pseudo code.)

Here is my read ...

Are you sure your I2C driver code is working properly? Or are you actually using a PC serial port?

I can supply my I2C and MOLCD code in Borland C, if this might help. The LCD code is for an LK202-25, but should be easily modified for whatever you want to drive.

Russ

Miles,

No email(s) received from you as yet. Do you have the correct address: home.rr@cogeco.ca

The "ping.be folks" refers to the URL given in the document for the LK202-25 where to get information regarding the I2C protocol.

The only email I've received was the one telling me I've been accepted ...

Miles,

I sent an email to you, but I haven't heard back yet.

Can you tell me how to contact the "ping.be" folks? I hound a couple of problems in their psuedo code for the I2C bus.

Russ

Hi, Tom!

I used:
0xFE 0x46 to turn backlight off
0xFE 0x42 0x01 to turn it on

Hi, I'm new to the forum. I have been developing driver software for the LK202-25 Matrix Orbital LCD (purchased from Parallax) to run on the JKMicro Flashlite 186 signle-board computer.

I am using the I2C interface. Everything seems to be working properly, with the exception of the backlight ...