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Best screen for my application (Digital Tachometer)

Posted: Thu Dec 24, 2009 10:40 pm
by RPMBasic
Hi,

I am currently making a digital tachometer for my car that will read out RPM, oil temp, and other vitals. I am using a BASIC Stamp 2SX chip, and I am wondering what you recommend in the way of a cheap screen to display the information on. I would like 4x20 or larger, and the bigger the better. Parallax recommends the LK-204-25, but at $100 it is a bit pricey, since I am trying to make the entire project under $100. They claim that their "...version is pre-modified for BASIC Stamp module-compatibility." What, if anything, would I have to do to modify one of your screens for use with a BASIC stamp? Any other insight would be much appreciated!

--Thanks

Posted: Thu Dec 24, 2009 11:39 pm
by Ray
The paralax models are premodified to use TTL levels instead of the regular rs232 levels, this modification is possible on all models and usually involves either setting a physical jumper or bridging 2 pads with a small blob of solder or 0 Ohm resistor, the manual will explain how this is done for each specific model.

Before i can recommend an alternative display i need to know what your requirements are. Do you need/want a keypad interface? do you require GPO's if so how many? Do you want 1-wire support?

Posted: Fri Dec 25, 2009 10:42 am
by RPMBasic
I don't need keypad interface, GPO's, or 1-wire support. I do need a backlight, as the car will be driven at night or in other adverse light conditions. Also, as this will be stored inside the car in a place that doesn't ever get below 40 F, so cold temps won't be a problem. Hot temperatures may become an issue, but I highly doubt that I will be leaving it in the car for extended periods of time.

Thanks for the prompt reply!

Posted: Fri Dec 25, 2009 10:54 am
by Ray
How about an MOS-AL204B-YX its a 4x20 for only $49 and it has 4.84 mm x 9.22 mm characters the largest we offer without moving to the more expensive graphical units.