5.4. The Matrix Orbital Driver (MtxOrb)
This section covers the installation process for the Matrix Orbital LCD module intended for use with LCDproc.
We will examine the installation process of the hardware in small steps, as it is vitally important to pay close attention to detail during hardware installation to avoid damaging equipment.
5.4.1. Matrix Orbital LCD Modules
LCDproc was born out of original tinkering by William Ferrell with one of these LCD modules. Their ease of installation and use (as well as the amazing amount of patience demonstrated by the folks at Matrix Orbital whilst William figured things out) meant one less thing to worry about during the early stages of LCDproc's life.
These 20x4 alphanumeric modules are connected via standard DB-9 cabling and connectors. They draw either 5V or 12V, depending on the module purchased, and are attached with a standard floppy cable connector (with a slightly modified wire configuration).
Once connected, using them is a breeze. They can operate at any number of different baud rates and serial configurations, but normally they run at 19,200 baud, 8-N-1, making them quite quick. Sending ASCII to the module will make it simply display that text at its current cursor position. The module has a built-in BIOS that recognizes commands (sent by transmitting a single-byte "marker" signifying that a command is on the way, followed by the single-byte command character itself along with any parameters, if needed) allowing the programmer to clear the screen, position the cursor anywhere, define custom characters (up to 8 at a time), draw bar graphs and large numbers, change the LCD's contrast, and so on.
The BIOS included also implements line-wrapping (i.e. writing past the twentieth character on the first row will automatically move the cursor to the first character on the second row), and screen scrolling (i.e. writing past the twentieth character on the fourth row causes the whole screen to scroll up one row, clearing the fourth line and positioning the cursor at the first character on that line).
These modules are fast. Using the auto-line-wrap feature and disabling the auto-scrolling feature, the screen can be updated thirty times per second if *every* character on the screen is changed. If updating less than the whole screen, the LCD can update faster than can be seen by the human eye. This, of course, more than meets LCDproc's needs.
5.4.2. Matrix Orbital Hardware Installation
Regardless of what specific type of hardware you intend to use with LCDproc, installation is usually straightforward, and requires only a few steps. Regardless, you must use caution while working inside your computer system or with any hardware attachments.
 | Installing new hardware inside a computer system can be dangerous to both system components and the installer. Use caution whenever adding a component to the inside of your system, altering a power cable, or physically mounting a device inside a computer system. When installing hardware inside a computer, make sure it's turned off and that its power is disconnected. This is especially important when making changes to power cables (as some LCD modules require). |
5.4.2.1. Matrix Orbital LCD/VFD Module Installation
The LCD and VFD modules from Matrix Orbital are relatively straightforward to install. With a small, regular (flat-head) screwdriver, a spare floppy drive power cable, and a bit of luck, installation will take less than an hour.
These installation instructions assume that you are installing the module into a PC or PC-style system (one with AT- or ATX-compliant power cabling) and that you have some idea of where you intend to permanently mount the module. For mounting ideas and tips, refer to the section "Mounting" below.
 | Before you start |
|---|---|
Your Matrix Orbital LCD or VFD module should be clearly marked with an indication of the module's power requirements. It should be either a 5 volt or 12 volt unit. You should have this information available before proceeding. |
5.4.2.1.1. Power Cable Modification
The first step in installing the module is making the necessary modifications to a floppy drive power cable in order to provide power to the module. The modifications must be made based on the module's power requirements -- either 5V or 12V -- depending on which module you purchased.
A standard floppy drive power cable has a smaller connection than a "normal" PC power connector. However, like a "normal" power connector, it has four wires: one yellow, one red, and two black. The red wire provides +5V power, and is "hot" or live when the system is powered up. The yellow wire provides +12V power, and is also hot when the system is powered up. Both black wires are ground. [TODO: INCLUDE A FIGURE HERE SHOWING A "STANDARD" FLOPPY CONNECTOR]
One of the hot wires and one of the black wires will not be needed for your module's power connection; they will be completely removed when the power cable modification is complete.
| Do NOT make this modification to a power cable attached to a running system! Electrocution resulting in personal injury and/or damage to the system can result. |
Using a regular screwdriver, press down the small metal locking flap of one of the two black wires on the small end of the cable, and pull the black wire from the connector. Using a pair of needle-nose pliers, squeeze the other end of the same black wire, and pull it out of the large end of the cable. This black wire can be set aside; it will not be used for the module's power connection. Either wire can be safely removed; you may safely remove either wire. [TODO: INCLUDE A FIGURE HERE SHOWING THIS PROCESS]
Next, using the same procedure, remove the unneeded hot wire. If your module is 5V, you do not need the yellow (+12V) wire. Conversely, if your module is 12V, you do not need the red (+5V) wire. The removed wire can be set aside; it will not be used for the module's power connection. [TODO: INCLUDE A FIGURE HERE]
The floppy power connector should now have only two wires attached to it. Leave the larger end alone from now on; these connections are correct (the larger end connects to your system's power mains). Move the two remaining wires to the outside connectors on the small end of the cable. Orientation does not particularly matter here; the connector will fit on the module's receptacle in either orientation. [TODO: A FIGURE HERE]
You should now have a properly modified power connector. When physically attaching this connector to the module, the black (ground) lead should be connected to the pin labelled GND, while the colored (+5V/+12V) lead should be connected to the pin labelled +5V/+12V.
Test the power connection before connecting the data line or mounting the module. Connect the module to the power connector, and the connector to your system's power mains. Turn the system on.
 | If the module does not immediately display its initial BIOS screen and light up its backlight (or light up the screen if a VFD module is being used), immediately power down the system, disconnect the module and connector, and double-check the modification before trying again. Do NOT leave the system on if the module does not immediately respond; module or system damage could result. |
When the LCD powers up and displays its initial BIOS screen, you've gotten the power connection wired properly and can now properly mount the module and make its final connections. Matrix Orbital Corporation sells a PC bay insert mount for the 20x4 and 20x2 modules (LCDproc, however, only supports the 20x4 at present). The inserts provide an easy means of mounting the LCD modules inside a PC using one (for the 20x2) or two (for the 20x4) 5 1/4" bays.
 | Describing how to physically mount the module in a PC case is beyond the scope of this document; LCDproc's website contains more detailed mounting information and examples. |
5.4.2.1.2. Serial Connection
The LCD module uses a standard DB9 serial connector. You can attach the module to your system using a direct cable to the motherboard, or by removing one of your system's serial ports from the back of the case, then connecting it to a standard serial cable to the module.
While connecting the serial cable to the module, be sure to configure the module's serial interface settings. Typically, setting the module to its fastest setting (19,200 baud, 8-N-1) is recommended. The speed settings can be configured from the config file /etc/LCDd.conf. If not specified in the config file, the Matrix Orbital module driver in LCDproc default to use these settings.
5.4.3. Copyright
This section was originally part of the lcdproc.sgml file by William W. Ferrell <wwf@splatwerks.org>
Slightly modified in order to include it in this document March 2002, Rene Wagner <reenoo@gmx.de>