From: "Pang" > Hi all, > > I have with me an LCD module and there's no way for me to determine it's > manufacturer and obtain the spec. What should I do? I have not really handle > any LCD module b4 as such any ideas will be greatly appreciated. The > physical attributes are --- 2 times 3.4 inch > -. 16 pinout on one side and 4 on the other side > -. There is a Made in Hong Kong sign and three Hitachi chips at the back > HD44100FS x 2 and HD44780A00. > -. There is a VL sign printed on the PCB > -. And finally ( but i cannot confirm ) the outside package has this number > MDL20265-LV-RC Sounds like a typical Hitachi 44780 based LCD. They are commonly found with 14 or 16 pin connectors and typically follow a somewhat "standard" layout. You should be able to find much information on these by searching for 44780 on Google. Pins 1-3 are (not in this order) Vcc, Vdd, and Contrast. Try hooking Contrast and Vdd to ground and Vcc to +5V. You should see the display initialize with rows of black blocks. If so, you are well on your way to getting it to work. If you don't see anything, try a slightly negative voltage on the Contrast pin (-1 to -2V should do it). Surprisingly these seem to be fairly durable. I recently made up a new breadboard and accidentally got the Vcc and Vdd backwards. While examining the circuit to determine why the blocks didn't show up, my calibrated face detected a fair amount of heat coming from the display. I quickly unhooked it and felt the back of the display, it was quite hot. :-O After correcting the wiring, it worked perfectly much to my amazement. ;-) YMMV I would still recommend using a current limiting resistor in the power supply before experimenting. IIRC, the display should require less than 5mA, but check the data sheet for a similar display. www.optrex.com should be a good place to start looking for info. Good luck michael -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics