Post by thread:How to load CGRAM in Optrex Modules (H44780)

In the Optrex data book: "CGRAM...which memorize characters that you can freely input by program." How? 5x7 characters would require at least 35 bits of information, and the data book has no protocol information on how to do this. Craig

Set your RS and R/W lines low, and write a 0x40 to the module.and toggle E. This will place the data pointer to point to CG memory (location 0) instead of display memory. Start writing your data 8 bytes of 8 bits (only the 5 least significant display) per character. When you are done, write an 0x80 to the display, and your cursor will home in display memory. To use the characters, they will be characters 0-7, so if you redefine the first character to be an up arrow and want to print an up arrow, use 'print chr$(0)' << this is BASIC Hope this helps Tony

Check out this link: http://www.eio.com/lcdintro.htm Lots of LCD info. Cheers, Kevin Craig Lee wrote: {Quote hidden}> > In the Optrex data book: > > "CGRAM...which memorize characters that you can freely input by program." > > How? > > 5x7 characters would require at least 35 bits of information, and the data > book has no protocol information on how to do this. > > Craig

Check out Myke Predko's web site at http://www.myke.com. He has recently added a section about how to define your own characters. On Fri, 30 Apr 1999 10:51:13 -0600 Craig Lee <spam_OUTcleeTakeThisOuTATTCANADA.NET> writes: {Quote hidden}> In the Optrex data book: > > "CGRAM...which memorize characters that you can freely input by > program." > > How? > > 5x7 characters would require at least 35 bits of information, and > the data > book has no protocol information on how to do this. > > Craig > Adam Bryant (age 0x23) .....abryantKILLspam@spam@peaktech.com (work) adamdbKILLspamjuno.com (home) Parker, CO, USA Robotics, RC Airplanes, anything using a PIC ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866]

ARudzki wrote: > Set your RS and R/W lines low, and write a 0x40 to the module and > toggle E. > This will place the data pointer to point to CG memory (location 0) > instead of display memory. Description a little bit fuzzy there, sorry! Writing (R/~W low) with RS low, writes a *command* while writing with RS high writes *data*, as when you send ASCII to the display. You first write a "Set CGRAM Address" *command*, then write all your *data* bytes in sequence. You then write a command to set the cursor position and the controller will thereafter accept further data writes as ASCII characters to be displayed including the new characters you have defined. Not comprehensive, but I hope a little clearer. -- Cheers, Paul B.

Hi Craig, >In the Optrex data book: First problem. Read the HD44780 data sheet instead, available off the Hitachi web site: semiconductor.hitachi.com/products/9_lcd/9_lcd/r_controllers_drivers/ 99RTD006D1/pdf/99rde.pdf Later, Eric

Hi Craig, Just to follow up on this. 1. You can get the information to do this from my LCD page as Adam pointed out: http://www.myke.com/engres/lcd.htm 2. I have been writing a couple of articles on the Hitatchi 44780 controller for LCDs for Bruce Reynold's "Rentron" site. You should look at: http://www.rentron.com/Myke2.htm I think this will have what you are looking for. Good luck and let me know if you have any questions, myke {Original Message removed}