Large LED Display

[Bill.b]

Has anyone used this display.

http://www.freetronics.com/collections/display/products/dot-matrix-display-32x16-red

It has been supplied for Arduino projects and has SPI interface so should be able to be used with
picaxe.


Bill

 

[westaust55]

While the basic data transfer is via SPI protocol in the absence of a schematic (at in the short term), the DMD connection diagram also shows NOE/PWM, A (D6), B (D7), C, D, G and R (D11_MOSI) as well as the SCLK (D8) and CLK (D13_CLK) pin identifiers.

In the absence of a schematic and links to controller chip datasheets one may have to work through the Ard@@no code to find out exactly waht signals as required and how to control the display.

 

[handyandy]

Hi Westaust55

I have two of these matrix I got them working using the darkside (a r u d u i n o) which i do not understand, i could write text, scroll text etc. How can i help you with gettings these to work with the picaxe. I can post photos of the back electronics and list details of the chips on them if that helps. It would be great to gets these working as they are only collecting dust at the moment.

http://learn.adafruit.com/32x16-32x32-rgb-led-matrix/wiring-the-16x32-matrix some info here about the pins

Large chip is a MW74Hc245D and then lots of the SM74HC595D around the board

on the din connector pins

L1 OE R1 A
L2 R2 B
L3 R3
L4 R4 CKL
L5 R5 SCLK
L6 R6
L7 R7 R
L8 R8

Photos here (large files host off the forumn)

http://www.phap.co.uk/images/picaxe/led1.jpg
http://www.phap.co.uk/images/picaxe/led2.jpg
http://www.phap.co.uk/images/picaxe/led3.jpg

 

[nick12ab]

How can i help you with gettings these to work with the picaxe.

I don't think it will. From the linked page:

Keep in mind that this matrix was designed to be run by a 250-pin 100 MHz FPGA, not a 16-MHz Arduino. To keep the speed and color resolution somewhat reasonable, we've hardcoded part of the pinout so that the 6-pin data bus (2 red, 2 green and 2 blue) must be on digital pins 2 thru 7 (pins 0 and 1 are reserved for uploading/downloading).

If the refresh rate is determined by how fast the microcontroller is sending the data then PICAXE won't work if Arduino struggles.

 

[Buzby]

Hi Nick,

The link you posted is to an RGB DMD, the OP only has a red version.

See here for the 128x32 DMD that OLDMarty and myself got working from a pair of 28X2s

http://www.picaxeforum.co.uk/showthread.php?22166-Newbie-with-DMD-display-amp-needs-to-speed-up-loops&p=218793&viewfull=1#post218793

The OP's 16x32 is probably similar.

Cheers,

Buzby

 

[handyandy]

Hi Buzby

That was quick, yes mine are only red leds. Thanks for the link, not sure i understand whats going on but will give me something to read up upon. How are the picaxe chips connected to the matrix and how would i get say "hello world" to display.

Thanks

Andy