Clock/Calendar/Thermometer with 64 x 8 Led Matrix Display
tomcrawford
Posts: 1,126
This note describes a clock/calendar using two Sure Electronics 3208 Monochrome Dot Matrix Display Information Board modules. The processor is a BS-2px along with a DS-1302 clock chip and a 1620 thermometer. An example of the result can be seen at http://youtu.be/whQSvz57Dps
The Sure 3208 is basically an HT1632C driving an array of 32 by 8 LEDs. They come in four flavors: {red/green} * {3 mm/ 5mm}. Here is a pointer to the data sheet: www.sureelectronics.net/goods.php?id=1119 I used two of them to form a 64 by 8 display.
I wanted a scrolling display; sort of a poor-man's Times Square so that I could show pithy statements. Since the display module itself has a fixed relationship between addresses in its array and the LEDs, I completely re-write the display array every time I move the characters. Basically, this is all the time. I used 64 bytes of the BS-2 RAM as a rotating buffer to contain my copy of what is on the display.
The connections are all either described or implicit in the code.
main.bpx contains the start-up code, most of the code that talks to the clock chip and thermometer, and calls other modules as needful. It is all pretty straight-forward, including the part that deals with Daylight Saving Time through 2020 (assuming that Congress doesn't mess with DST again).
fonts.bpx contains a 5 X 7 font (with descenders) and the code that drives the array. The heart of the code is at PutAscii which takes an ASCII character code of puts 7 columns (5 font columns or two blank columns) into the buffer. Each time it puts a column into the buffer, it calls DArray which writes the entire array into the display modules. IPnt and OPnt keep track of where the top of the display end is.
adjust.bpx is used to set the time, etc. It uses a separate display driver since this information doesn't need to scroll.
pithy.bpx (and pithy2, 3, and 4) select a random pithy saying to be displayed between the time and temperature. There is room for about 150 sayings of an average length of something like 50 characters each. There is a fifth source of sayings, not included here, that includes holidays, birthdays, and weddings.
The Sure 3208 is basically an HT1632C driving an array of 32 by 8 LEDs. They come in four flavors: {red/green} * {3 mm/ 5mm}. Here is a pointer to the data sheet: www.sureelectronics.net/goods.php?id=1119 I used two of them to form a 64 by 8 display.
I wanted a scrolling display; sort of a poor-man's Times Square so that I could show pithy statements. Since the display module itself has a fixed relationship between addresses in its array and the LEDs, I completely re-write the display array every time I move the characters. Basically, this is all the time. I used 64 bytes of the BS-2 RAM as a rotating buffer to contain my copy of what is on the display.
The connections are all either described or implicit in the code.
main.bpx contains the start-up code, most of the code that talks to the clock chip and thermometer, and calls other modules as needful. It is all pretty straight-forward, including the part that deals with Daylight Saving Time through 2020 (assuming that Congress doesn't mess with DST again).
fonts.bpx contains a 5 X 7 font (with descenders) and the code that drives the array. The heart of the code is at PutAscii which takes an ASCII character code of puts 7 columns (5 font columns or two blank columns) into the buffer. Each time it puts a column into the buffer, it calls DArray which writes the entire array into the display modules. IPnt and OPnt keep track of where the top of the display end is.
adjust.bpx is used to set the time, etc. It uses a separate display driver since this information doesn't need to scroll.
pithy.bpx (and pithy2, 3, and 4) select a random pithy saying to be displayed between the time and temperature. There is room for about 150 sayings of an average length of something like 50 characters each. There is a fifth source of sayings, not included here, that includes holidays, birthdays, and weddings.
Comments
You should post this in the Projects forum, with a schematic. That's what it's there for!
solved 2 x 5 each up to 4 connected