sure electronics LED dot matrix HT1632c Energia example

32x8 LED dot matrix display

32×8 LED dot matrix display

This LED array has been sitting in my room for months now so I decided to hook it up to an msp430g2553 and get it displaying stuff. I bought it from ebay from a chinese supplier called sure electronics. The array is controlled by a ht1632c led matrix driver chip and the interface required is clocked serial data which I wrote in software for the msp430. There are arduino libraries out there for interfacing with this driver chip and I used them as a reference when putting this together. Right now all I have working is initialising the driver chip and writing data to its ram to display various patterns. The leds are mapped directly to the ht1632c ram. i.e. if you write a ‘1’ to a certain memory address that led will come on and writing a ‘0’ will turn it off. The chip has some other cool features like 16 level PWM dimming also. Only 4 wires (plus Vcc and GND) are needed to interface with the led array. The four wires are DATA, WR(clock), CS (this pin is pulsed to switch between read,write and command modes on the ht1632c) and the RD pin which is the data out from the ht1632c. This data out could be the contents of the RAM so you could find out which leds are on. I didn’t use this pin at all so it’s really only 3 wires which is pretty handy. These LED array boards can be chained together up to a max of 4. Right now I only have one so the code written is meant to just control one chip. That being said it shouldn’t be too much hassle to get it working with several boards at once.

Here is the code I wrote using the Energia IDE :

If you connect the LED array using the same pins I’ve defined for DATA, WR and CS it should work right away displaying the twitter logo scrolling across the screen. Here is a picture of it displaying a speaker of some type:

led array displaying speaker

led array displaying speaker

If you’re interested in displaying text then check out this really extensive arduino library for the ht1632c.

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