how to mount a lcd display onto a robot

[mechanicalbrain]

I wanted to take a LCD screen (like one of these click here) and physically mount it on our robot. I searched some threads but couldn't find anything of satisfaction. I know it works by a series of digital I/O signals but am not sure how i would go about wiring it or programing it. I want to use this to display info entered in by a keypad. I know how to wire it to a serial cable (doesn't help me much in terms of mounting to the robot).

[sciguy125]

It has 4 mounting holes. Why not screw it to a piece of sheet metal and bend it into some sort of panel?

[sanddrag]

Sounds like a plan to me. Even one of those plastic project boxes would work if you carefully dremel a cutout in it. If you go the metal route, I would recommend bending the metal before intstalling the LCD, hehe.

As for wiring and programming, aren't you going to need some sort of external driver circuit? I didn't think you could just hook up the LCD to the RC. I don't know too much about LCDs so I too am interested in the wiring/programming/circuit discussion.

[mechanicalbrain]

Originally Posted by sciguy125

It has 4 mounting holes. Why not screw it to a piece of sheet metal and bend it into some sort of panel?

I meant wire it not physical mounting but thanks for the post i was getting worried nobody would try to help. i know that the STAMP can control one so i dont see why a FIRST board couldnt. i Know its a I/O device but thats it.

[mechanicalbrain]

Here is a pdf guide http://www.robotshop.ca/PDF/rbnet31_hard.pdf to wiring it to a serial port. if someone creative could help me figure out how to get it to run on the robot i would vastly appreciate the help.

[Al Skierkiewicz]

To start, I would recommend the LED backlight as the EL style needs a high voltage power supply. The programming and other controls are easily handled by a Basic Stamp in most cases. (Parllax actually sells a module in their line) They are small so not easily readable from a distance but can be made to scroll messages easily enough. They need to be protected from abuse, bending and shock and are best inside a rugged case with a window. I would not use the RC for data, you need that for important stuff. It might make a really nice handheld data sniffer or interface for an OI.

[sciguy125]

It seems like you can just connect it to the serial port on the RC. You get a choice between the program port and TTL serial port. Just remember that the TX pin on the RC needs to connect to the RX pin on the LCD module and vice versa. At that point, you can use printf() to send data to the module. I'm not sure how to read it though. Does the FIRST code have some sort of input from the serial port? I suspect it would be scanf() if it has it.

What exactly are you trying to do with it?

[mechanicalbrain]

Originally Posted by Al Skierkiewicz

To start, I would recommend the LED backlight as the EL style needs a high voltage power supply.

The nice thing is that they run off of 12 volts which is easier to use than the led backlights which are +5 volts i believe.

[foobert]

the character lcd modules on the site you reference are not serial devices. they require either 7 or 11 i/o lines. with seven i/o lines they transfer 4 bits at a time and require two transfers to send a single byte.

if memory serves the i/o lines are ...

e - which strobes the data into or out of the lcd
r/s - which tells the lcd whether you are sending data or a command
r/w - which tells the lcd whether you are performing a read or a write operation
d1 - data line 1
d2 - data line 2
d3 - data line 3
d4 - data line 4

with 11 i/o lines, you use four more data lines and transfer data a whole byte at a time.

you also need to supple 5v, ground, and connect a 10k pot to control the display contrast. with a backlit display you also need to supply power for the backlight. the protocol to get these devices configured is a little baroque, but not too bad.

the displays use a hitachi 44780controller, which is explained pretty well here .

[mechanicalbrain]

Yeah i ended up buying it and it works great!