diff --git a/docs/lcdproc-user/drivers/hd44780.docbook b/docs/lcdproc-user/drivers/hd44780.docbook index 686dd08..2241d28 100644 --- a/docs/lcdproc-user/drivers/hd44780.docbook +++ b/docs/lcdproc-user/drivers/hd44780.docbook @@ -2,33 +2,135 @@ The HD44780 Driver -There are several ways of wiring up the HD44780 devices. Your choice -will probably be governed largely by your ability to wire up each one -and/or a desire to use the device with other programs. +The HD44780 has become the de-facto standard of alphanumeric character displays. +Although the original Hitachi HD44780 is long out of production, its command +set has survived in a variety of (fully or nearly) compatible LCD, VFD and +even OLED displays sold by a broad range of manufacturers all over the world. +To name ony a few: KS0066, KS0070, KS0076, LC7985, NT3881, SED1278, ST7066 ... -The LCDproc HD44780 driver supports the following connections on a -parallel port: +The command set of these displays, which sometimes are advertised as being +"industry standards compatible", is thus the workhorse of controllers for +displays ranging from 8x1 to 20x4 or 40x2 characters. +There are even displays with larger dimensions sporting two controllers, +one for each half of the display. + + + +The HD44780 driver supports various ways of connecting HD44780 devices +to your system. +Each of these different ways is called a connection type of the driver. + + + +On a parallel port, probably the first interface type HD44780 devices were +historically connected to, the driver supports the connection types: - 4bit - 8bit (winamp style) - extended 8bit (LCD + LED bargraph) - serial LPT + + 4bit: + 4bit Wiring + + + + 8bit: + 8bit Wiring ("lcdtime") + + + + winamp: + 8bit Wiring "winamp" Style + + + + serialLpt: + Serial LPT Wiring + -It also supports the following connections: +For serial RS-232 ports you can choose among these connection types: - A PIC-an-LCD or LCD serializer connected to a serial port - A I2C port expander connected to an I2C port - USB connection via a FTDI FT2232D chip in bitbang mode + + picanlcd: + PIC-an-LCD serial device + + + + lcdserializer: + LCD serializer + + + + los-panel: + LCD on Serial panel device () + + + + vdr-lcd: + VDR LCD serial device + + + + vdr-wakeup: + VDR-Wakeup module + + +In recent years, with with parallel ports and serial ports being declared legacy +and on the demise on modern computers, the USB connection types get +more important. Here are the USB connection types the HD44780 driver supports: + + + + + pertelian: + Pertelian X2040 LCD display () + + + + bwctusb: + BWCT USB LCD module () + + + + lcd2usb: + Tim Harbaum's LCD2USB () + + + + lis2: + LIS2 from VLSystem () + + + + mplay: + MPlay Blast from VLSystem () + + + + ftdi: + Display connected to a dual channel FTDI 2232D USB chip + + + + +Last but not least, for special purposes, there are even more connection types: + + + + + i2c: + LCD driven by PCF8574(A)/PCA9554(A) connected via I2C + + + + The driver also lets you use multiple displays as a single virtual display. For example, a 4, 2 and 1 line display can be used to form a @@ -106,7 +208,7 @@ There are several ways to get 5V: black is GND). - Get it from the VCC pin of an USB connector. + Get it from the VCC and GND pins of an USB connector. Get it from a joystick port (pin 1 and 9 are 5V, 4, 5 and 12 are GND). @@ -467,7 +569,7 @@ The BC327 transistor has the following connections: 4bit -This is originally based on "lcdtext" (by Matthias Prinke). +This wiring is originally based on "lcdtext" (by Matthias Prinke). @@ -1999,7 +2101,7 @@ Refer to burning section in -BWCT USB device "bwctusb" +BWCT USB LCD module "bwctusb" The BWCT USB LCD module is also supported. It is not connected to an LPT port @@ -2307,22 +2409,24 @@ This can be done by specifying or by inclu + 4bit - HD44780 4bit Wiring (default) + 4bit Wiring to parallel port(default) 8bit - HD44780 8bit Wiring ("lcdtime") + 8bit Wiring to parallel port ("lcdtime") winamp - HD44780 8bit Wiring "winamp" Style + 8bit Wiring "winamp" Style to parallel port serialLpt - HD44780 Serial LPT Wiring + Serial LPT Wiring + picanlcd PIC-an-LCD serial device "picanlcd" @@ -2343,6 +2447,7 @@ This can be done by specifying or by inclu vdr-wakeup VDR-Wakeup module "vdr-wakeup" + pertelian Pertelian X2040 LCD display () @@ -2363,14 +2468,15 @@ This can be done by specifying or by inclu mplay MPlay Blast from VLSystem () - - i2c - LCD driven by PCF8574(A)/PCA9554(A) connected via I2C - ftdi Display connected to a dual channel FTDI 2232D USB chip + + + i2c + LCD driven by PCF8574(A)/PCA9554(A) connected via I2C + diff --git a/docs/lcdproc-user/drivers/ppttrouble.docbook b/docs/lcdproc-user/drivers/ppttrouble.docbook index 65b2307..f1543d5 100644 --- a/docs/lcdproc-user/drivers/ppttrouble.docbook +++ b/docs/lcdproc-user/drivers/ppttrouble.docbook @@ -12,167 +12,183 @@ of electronics. The following hints might be helpful: + Check The Wiring + -Wiring errors can easily be made. If you are unexperienced -with the soldering iron better have someone solder it for -you. Display modules are sensitive to electro static -discharges, so touch an earthed surface (computer case, -water pipes...) before you handle these. +Wiring errors can easily be made. +If you are unexperienced with the soldering iron better have someone solder +it for you. +Display modules are sensitive to electrostatic discharges, so touch an +earthed surface (computer case, water pipes...) before you handle these. + Power Source Unregulated / Noisy + -Make sure your power supply delivers steady 5 Volts with- -out noise or interruptions. The bare wall plug in trans- -former is not suitable, though you can make it stabilized -by adding an 7805 and a few capacitors. -Some noise induced in the supply lines my be tricky to -track, even if you have an oscilloscope. +Make sure your power supply delivers steady 5 Volts without noise or +interruptions. +The bare wall plug-in transformer is often not suitable, though you can +make it stabilized by adding an 7805 and a few capacitors. +Some noise induced in the supply lines my be tricky to track, even if +you have an oscilloscope. + Ground Lift + -The power supply wires and especially the GND wires should -be a little thicker than the other wires. If GND is not -thick enough (or not existent, see 1) the resistance of the +The power supply wires and especially the GND wires should be a little thicker +than the other wires. +If GND is not thick enough (or not existent, see 1) the resistance of the wire may cause differing GND potentials in the circuit. -This may lead to strange display behaviour. It may also be -wise to solder a 100nF capacitor directly to the GND and -VCC pins of the display. +This may lead to strange display behaviour. It may also be wise to solder +a 100nF capacitor directly to the GND and VCC pins +of the display. + Latchup + -Never let the supply voltage get much below the io signal -voltage. It may lead to a latchup condition which will -destroy the controller chip on the display. +Never let the supply voltage get much below the io signal voltage. +It may lead to a latchup condition which will destroy the controller +chip on the display. + Contrast + -If you don't see anything on your display it may be that -your contrast voltage is set wrong. Turn your contrast -potentiometer all the way to the end connected to GND. +If you don't see anything on your display it may be that your contrast voltage +is set wrong. Turn your contrast potentiometer all the way to the end connected +to GND. Contrast is highest then. + Beware -The module you got so ultra cheap may be an -enhanced temperature model which needs a negative -contrast voltage for sufficient contrast - see chapter +The module you got so ultra cheap may be an enhanced temperature model which +needs a negative contrast voltage for sufficient contrast - see chapter 99 on how to make negative voltage. + Parallel Port Voltage + -Many modern mainboards and especially notebooks will not -nearly output 5V for a logic H as the older parallel ports -did, because the operating voltage of computers is lower than -5V these days. I have measured voltages between 2.5V and 4V -for logic H, which is barely within specification of the -HD44780. If you account RCL of your cable, this may not be -enough and can cause unreliable operation. +Many modern mainboards and especially notebooks will not nearly output 5V for +a logic H as the older parallel ports did, because the operating voltage of +computers is lower than 5V these days. +I have measured voltages between 2.5V and 4V for logic H, which is barely +within specification of the HD44780. +If you account RCL of your cable, this may not be enough and can cause +unreliable operation. + Enable Signal Rise Time + -If you ever read the HD44780 datasheet you will notice that -somewhere in the 'signal timing' table is written: 'Enable -Signal Rise Time max. 20nS'. That means the Voltage on the -HD44780 pin called 'Enable' has to rise from 0 Volts to 5 -Volts within 20 Nanoseconds and the other way round. They -should better print that in big fat red letters, because -most HD44780s are really picky about the enable signal rise -time. +If you ever read the HD44780 datasheet you will notice that somewhere in the +'signal timing' table is written: 'Enable Signal Rise Time max. 20nS'. +That means the Voltage on the HD44780 pin called 'Enable' has to rise +from 0 Volts to 5 Volts within 20 Nanoseconds and the other way round. +They should better print that in big fat red letters, because most HD44780s +are really picky about the enable signal rise time. + -That is a Problem: If you count together the bad driving -characteristics of the parallel port combined with the -capacitance of flat ribbon cable you may easily get an -order of magnitude slower rise time. -Therefore you should only use really short cable ( shorter -than 50cm) for connecting the display to the parallel port. -It may also be useful to use pull-up resistors on the display -module or a schmitt-trigger. +That is a Problem: If you count together the bad driving characteristics +of the parallel port combined with the capacitance of flat ribbon cable +you may easily get an order of magnitude slower rise time. +Therefore you should only use really short cable (shorter than 50cm) +for connecting the display to the parallel port. +It may also be useful to use pull-up resistors on the display module +or a schmitt-trigger. + -The rise time of a digital output can (usually) not be -altered by Software. +The rise time of a digital output can (usually) not be altered by Software. + EMI + -The cable from the parallel port to the display may -be sensible to electromagnetic interference and may emit -electromagnetic radiation. If you place your cellphone near -the cable, you may get unexpected display readings, on -the other hand your house neighbour may not be able to listen -to his/her favourite radio station any more - so better use -shielded cable and put the display in a metallic case, perhaps -a computer case. +The cable from the parallel port to the display may be sensible to +electromagnetic interference and may emit electromagnetic radiation. +If you place your cellphone near the cable, you may get unexpected display +readings, on the other hand your house neighbour may not be able to listen +to his/her favourite radio station any more - so better use shielded cable +and put the display in a metallic case, perhaps a computer case. + One or Two Black Lines + -If you see one or two black lines on the display it means -nothing more than that the display is powered and contrast -voltage is present. If one or two black lines appear the -controller has not been reset properly by the on chip power -on reset generator. No need to worry - it will be reset by -the LCDd software. But if the -black line will not disappear -although the wiring is working, the controller on the display -may be defective. +If you see one or two black lines on the display it means nothing more than +that the display is powered and contrast voltage is present. +If one or two black lines appear the controller has not been reset properly +by the on chip power on reset generator. No need to worry - it will be reset by +the LCDd software. +But if the black line will not disappear although the wiring is working, +the controller on the display may be defective. + Software Too Fast + -If you have a super GHz computer it may happen that the signal -timing generated by LCDd is too fast. -Adjust DELAYMULT in the -source file to a bigger value. Parallel port wirings usually -don't permit to read back the busy flag of the controller chip, -so timing must be adjust so that the controller never is busy. +If you have a super GHz computer it may happen that the signal timing generated +by LCDd is too fast. +Adjust DELAYMULT in the source file to a bigger value. +Parallel port wirings usually don't permit to read back the busy flag of the +controller chip, so timing must be adjust so that the controller never is busy. + LED Backlight + -Check whether you need a resistor for your LED Backlight and -which value it should have. If you forget the required resistor -the backlighting LEDs might become hot and draw excessive -current. +Check whether you need a resistor for your LED Backlight and which value +it should have. +If you forget the required resistor the backlighting LEDs might become hot +and draw excessive current. + HD44780 Compatible + -The original HD44780 controller that we advertise to support -has become the industry standard for alphanumeric character -displays. The original HD44780 is out of production. It has -many successors from many manufactures, which sometimes won't -tell you that their chips are 'compatible'. +The original HD44780 controller that we advertise to support has become the +industry standard for alphanumeric character displays. +The original HD44780 is out of production. It has many successors from many +manufactures, which sometimes won't tell you that their chips are 'compatible'. -To name a few: KS 0066, KS 0070, KS 0076, LC 7985, NT 3881, -SED 1278, ST 7066 ... +To name a few: KS0066, KS0070, KS0076, LC7985, NT3881, SED1278, ST7066 ... + Miscellania