Post by thread:[PICLIST] [OT] LCD determinate + or

Hi, i have bought a LCD BT 22008 R1 2*20 display. I got very limited in- formation about this LCD only a short note about the 14 pin connector. 1 GND; 2 VDD; 3 V0; etc. So i tryed to run it by applying +5 voltage and so, also +5V via a trim resitor for the driver. But nothing the display shows no reaction at all. If i change the driver voltage from 0 to 5 Volt no dark squares appear, even after a software initialization still no change. Currently my test hardware can only write to a LCD and this is working very well with a different LCD. Until now i have only used 0 to +5V for the driver voltage, but it could be a LCD need negative voltage. But how i can determinte if this LCD need + or - driver voltage by my self ? So far i could not find anything in the net/data sheets regarding this problem. The supplier is selling almost everything in short quantities, so i do not expect to much help from there. Thanks for any hints. Thomas -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

----- Original Message ----- From: Thomas Krampe <.....Thomas.KrampeKILLspam@spam@T-ONLINE.DE> > Until now i have only used 0 to +5V for the driver voltage, but it > could be a LCD need negative voltage. But how i can determinte if this > LCD need + or - driver voltage by my self ? > > So far i could not find anything in the net/data sheets regarding this > problem. > > The supplier is selling almost everything in short quantities, so i do > not expect to much help from there. I had similar problems for the past month. The pinout numbers on the header sometimes is a bit different from what you see in datasheets for different products, sometimes the pin number order is rotated or the pins are numbered 1 from one end or the other, even though the physical pinouts are compatible. Here is one possible arrangement: http://www.repairfaq.org/filipg/LINK/F_LCD_HD44780.html Some test software download and another pinout setup: http://home.iae.nl/users/pouweha/lcd/lcd2.shtml If you have a two column header on the left side it might be: d7 d6 d5 d4 d3 d2 d1 d0 E RW RS Vo G +5 Jeff demaagd.com -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestKILLspammitvma.mit.edu

Jeff DeMaagd schrieb: {Quote hidden}> > The pinout numbers on the header sometimes is a bit different from what you > see in datasheets for different products, sometimes the pin number order is > rotated or the pins are numbered 1 from one end or the other, even though > the physical pinouts are compatible. > > Here is one possible arrangement: > > http://www.repairfaq.org/filipg/LINK/F_LCD_HD44780.html > > Some test software download and another pinout setup: > http://home.iae.nl/users/pouweha/lcd/lcd2.shtml > > If you have a two column header on the left side it might be: > > d7 d6 > d5 d4 > d3 d2 > d1 d0 > E RW > RS Vo > G +5 > Hi Jeff, thank you for you help, but i was just the need for negative LCD driver voltage. I simply give it a try and its work. The sentence which come up on one of your links says everything: 'LCD displays are fun. (when they work)' Thomas -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads