Matrix Orbital Corp

Hello all,

I'm new to the pic world and I have already done some work with them like turning leds on and using the A/D converter, etc. Now I want to move to a serial LCD and use the PIC 16F877A to display data on it, like voltage, RPM, temperature and some other things. I want to use ASM and I have been trying to find a tutorial or some kind of help for this. I couldn't find much info on using the serial LCDs with Microchips and what I found was all parallel in either 4 or 8 bit settings. I want to use the matrix orbital 20x4 LCD with a PIC 16F877A using the USART.

http://www.matrixorbital.ca/manuals/LK_ ... 204-25.pdf

If anyone can help me out here I would appreciate it. Remember that I want to do it in assembly. Also what is recomended RS-232 or I2C?

Hi,

What you use really depends on what you like. RS232 is the easiest protocol out there but I2C isn't much more complicated (It's just addressed). If you have a hardware USART at your disposal, I would go with the RS232, it is a little simpler to get started and generally is easy to trouble shoot when things do get strange. Just remember to make sure that you either have a voltage level shifter on your board (like the MAX232 or similar) or have the LK204-25 configured for TTL.

As for app notes; your right we don't have many app notes for the PIC. For the most part, Microchip has so many really good app notes, that it's really not needed.

Check out AN774 available on the Microchip web site. This is a basic starter document that covers the USART in assembly. Once you are comfortable with the PIC USART, it really is as straight forward as making the connections between your board and the LKL204, reading the LK204 manual for the instruction set, and talking to the display.

As always, if you find your self having issues, drop us a message on the forum detailing your particular problem and we'll jump in and help as much as we can.

Brian Ingwersen
Engineering
Matrix Orbital