Dnia 2011-01-11, wto o godzinie 13:06 +0100, Zoff pisze: > could you post the changed circuit? I have bought the hobbyboards LCD and would like to change it > to turn backlight on/off. It should be very easy. The LCD has backlight power probably on pins 15-16 or on 1 and 2. I think that 1 and 2 is less common. Mine has pin1-GND pin2-5Volts. You can try to apply voltage to one of those pins when the lcd is powered off or you can read the lcd model from the back and try to find datasheet. Then you have to get PIO.0 signal and connect it to a transistor. The transistor works as a switch/key so the current for the backlight goes through it instead going through DS2405. I don't know how does Hobby boards LCD look like but from guessing form the schematic you could take it from one of the switches. They should be already connected by 10kOhms resistor to VCC so you just need to add this 2kOhms resistor(actually I'm not sure resistor is essential)
I'm not very good at electronics so maybe this circut is not perfect but it works. I think the BC548 transistor could be any other NPN transistor. These parts are cheap, you will get them in every electronics store. Initially the backlight is off but when you write "0" to PIO.0 it should lit. Unfortunately after writing to screen/message PIO.0 resets. P4trykx http://img121.imageshack.us/i/dsc00906ph.jpg/ http://img651.imageshack.us/i/dsc00905t.jpg/ > > cheers, > Zoff. > > patyrk wrote: > > Hello again > > I've built myself a LCD display based on Hobby Boards design with some > > minor changes. Instead id three push buttons I wired PIO.0 to a > > transistor which turns backlight on an off. > > When I write 0 to PIO.0 backlight turns on. > > But when I clear the display or write to the message PIO.0 also changes. > > Could other PIO.0 PIO.1 PIO.2 be left alone while writing to the > > display? > > > > And another question about displays. I figured out that message has 4x20 > > characters. I have 2x16 LCD. The order is 1 line , 20+4 chars(not > > displayed) and then second line. What if I would use 4x40 display? > > > > > > P4trykx > > > > > > ------------------------------------------------------------------------------ > > Gaining the trust of online customers is vital for the success of any company > > that requires sensitive data to be transmitted over the Web. Learn how to > > best implement a security strategy that keeps consumers' information secure > > and instills the confidence they need to proceed with transactions. > > http://p.sf.net/sfu/oracle-sfdevnl > > _______________________________________________ > > Owfs-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/owfs-developers > > ------------------------------------------------------------------------------ > Gaining the trust of online customers is vital for the success of any company > that requires sensitive data to be transmitted over the Web. Learn how to > best implement a security strategy that keeps consumers' information secure > and instills the confidence they need to proceed with transactions. > http://p.sf.net/sfu/oracle-sfdevnl > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ Gaining the trust of online customers is vital for the success of any company that requires sensitive data to be transmitted over the Web. Learn how to best implement a security strategy that keeps consumers' information secure and instills the confidence they need to proceed with transactions. http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
