LCD Screen?

Could you get an LCD screen to work with a VEX microcontroller? I accidentally bought one off ebay and was just wondering…

What is the interface for sending data to it???

How much do the “little grunts” cry???

Well, it is a LCD meant for a Parallax BASIC stamp system, but I have no problem rewiring things… It is a 16 character x 2 (2 lines that is) LCD screen w/ backlight. This isn’t the place I bought it from, but this is the same screen And the grunts cryed soo much, they made the rivers of Halo :slight_smile:

Judging from the picture on the ebay listing, it does not include the serial to parallel interface that the parallax unit has. That means that you can connect it to your Vex controller, but it will take a minimum of 7 data lines to do it. You also have to add a potentiometer in the circuit to set the LCD contrast.

If it does include the serial interface, then it looks like you can plug it directly into the TX port on the top of your Vex controller using an extension cable.

And the grunts cryed soo much, they made the rivers of Halo :slight_smile:

Hmm, “LCD meant for a Parallax BASIC stamp system” seems to imply a Serial Interface and the link you posted to Parallax has for the First Download, [Parallax Serial LCD Documentation v2.0 (.pdf), which indicates “Works at 2400, 9600, and 19,200 baud”.

Does anyone know if the Serial Interface on the “BASIC stamp system” is TTL voltage levels, becaue that is what the Vex Controller is.](“”)

The manual for the Parallax Serial LCD seems to show that it is indeed TTL level. The pinout of the connector is even right for plugging directly into the vex controller with just an extension cable.

I was looking for that information, where did you locate it in the manual??

The pinout is apparent from the outline drawings.

The TTL reference is indirect, and it’s not in the manual itself as I had thought. Rather, it is in the web page in the original reference:

Since the PC is RS-232, and a MAX232 is used to convert RS-232 to TTL, I infer that the LCD requires TTL levels.

Got Cha!! I would “infer” the same thing… Thanks for the Info…

I am thinking it would be nice to use one of these display for Debug info on the Vex…

Thanks a load, now all I have to do is ask the school to lend a programming kit…LOL I’ll let you guys know how the screen works with VEX, if it works good, then you now have a way to get cheap ($5.85) debug screens!

hooking a parallax LCD screen up to the vex sounds cool but i wonder if theres a way to program your vex to have a couple buttons hooked up to external IC’s so you can program the vex by just using some small butons but that would probably be too hard

You would have to make an Editor and Language Interpreter in ‘c’, that would process you Button Presses, and then let you execute the instructions you entered…

from a scale of 1-10 how hard exactly is it for easy C beginner b/c i dont have easy kit yet but still think im gonna geto ne eventually

If you have some basic idea of code you’ll have no problem with easyC. If you’ve ever used the lego mindstorms code you’ll have no problem with easyC. If you are determined and ask for help here you’ll pick easyC up quickly. I find it was really easy to find out what was going on.

I’ve programmed in Visual BASIC, PBASIC, soon to be AXEBASIC (not the proper term), and lego mindstorms, so I think I could handle easyC, especially with ‘easy’ in the title. I just can’t afford any of the parts here at this site, including the programming kit, so I think I might just get the guys at my local radioshack to hunt the stuff down for me, of course I’d have to pay extra to utilize their time and also since it is an uber-low clearance item, although the parts aren’t $1.95 YET

Hey MasterChief,

Just curious - I’m not poking fun at all - but how do you “accidentally” purchase an LCD screen?


u can accidentally bid on it without thinking first and once you bid you cant take that bid back which is pretty stupid

You can retract a bid if some else has bid on the item as well. in that case the runner-up would be the top bidder. :slight_smile:


Heavy metal pretty much said it exactly, and the screen is a parallel interface, but I bought the parts to convert it to serial, I just need to buy some cheap perf board and find the right potentiometer and I think I’m set. And I don’t even need the perf or pot, they just make things “neater”

I hooked up my kit a month or so ago, kinda, I accidentally soldered in the resonator wrong, so when I was desoldering it I accidentally snapped the lead off of it :eek:, and it is too short to solder a wire to (trust me, I tried :mad:), so I’m going to order some parts in a week or so, once I finally get this nightmare taken care of, I’ll post links to all of my sources if all goes well and I get the LCD performing fully on the VEX (I’ll try). If it goes well then we all will know how to get a working serial interface 2 x 16 backlit LCD for about $12 (with quite a bit of soldering, of course:rolleyes: )