11-29-2006, 07:25 PM
Hello I'm trying to interface an HDSP 2111·LED Dot Matrix display to a BS2.· I've got the data sheets for the display but I'm new at interfacing displays and I can't get it to work.· I've searched the internet and cannot come up with any· information except that the display can be controlled from a PIC or Basic Stamp.· Does anybody have a sample program or pin connections that could help me?·
OK, I didn't really have time this morning before work to go over the datasheet in detail (attached below), but it looks this is the basic setup for this display (nice display but seems like it uses a LOT of pins to get throughput on data). This is not code, but what I think is the general flow for getting data to the display...
1. LOW CE (CHIP ENABLE), LOW WR, HIGH RD (you may be able to tie WRite LOW and ReaD HIGH if you don't plan on reading from chip which would save two pins)
2. set address lines A0-A5 to correct control and/or character register (are you writing a character? setting brightness). This uses 3-5 pins from Stamp
3. clock out data byte on D0-D7 and CLK (another 9 pins). This chip receive entire bytes in one shot on each clock pulse
4. HIGH CE to disable chip from receiving more data on the data bus
I would try for a start just blanking/unblanking display. By my count you need a minimum of 8 data lines, 5 address lines, clock, enable, write, read to your Stamp, which is what, 17 pins? Hoo boy. You may want to think about using an HC595 shift register to control the WR, RD, CE and address lines which would save you 5 pins. For testing you may just want to hold WR low and RD high as mentioned above to save two pins and just don't worry about reading from the display.
Page 9 of the data sheet has the explanations of each pin. Again I didn't have a chance to go over the sheet in detail, so I may have missed something in the differences between writing characters to the display and to flash memory (which seems to be the biggest address pin hog).
When the going gets weird, the weird turn pro. -- HST
10-25-2010, 05:07 PM
Did anyone ever get this to work - otherwise I'll try and post when I do.