LEDgoes Displayboard
The Displayboard is the flagship offering of LEDgoes. Visit our main site at http://www.ledgoes.com to see what it can do!
To purchase an LEDgoes Displayboard, head on over to http://www.makertronic.com/ledgoes.
It consists of the following components:
- Custom PCB
- (2) ATmega168 processors
- (11) 33 ohm 0805 surface mount resistors (the design also supports through-hole, and can accommodate 1206 and 0603 SMD parts)
- (2) 16MHz ceramic oscillators of (size unknown)
- (2) 14-pin female header pins
- (1) 6-pin right-angle male header pins
- (1) 6-pin right-angle female header pins
- (1) CSM57281EG 5x7 dual-color LED matrix
Each board sold offers the following features:
- All 13 digital I/O pins from each chip exposed through the headers; TX & RX accessible through the sides, others through the top & bottom
- Three analog input pins exposed from each chip; one through the sides, two through the top
- 10 test pads allowing access to each chip's MOSI/MISO/SCK/RST, plus the common power & ground
- Auto-addressing capability -- hook the boards up in any order you wish, and see the same output.
- The board is designed to run at 5V.
- The supported baud rates are supposed to be listed in the LEDgoes software. Changing the baud rate will require reprogramming all your chips. 9600 is the minimum tested and looks good until about 6 boards in length. 19200 is currently being tested, and we anticipate a maximum of 115200 baud or possibly 230400. You can hack the software to change the baud rate to an unsupported speed. We anticipate boards will come from the factory at 115200.
- The TX & RX lines run throughout all processors, or at a very minimum, both processors on the board if you decide to sever the TX/RX connections between boards. The path for ADC7 (the auto-addressing signal) also runs throughout all processors, but can be broken by removing the surface-mount resistor in the spot called out in the diagrams below. This does not break it between processors, but only between boards.
To view the board file presented for download here on GitHub, you should download Eagle CAD 6.5 or newer. It is free software for non-commercial use, so the free version just to look at it should be OK.
Following is a description of each pad on the board.
The first diagram describes which pins activate which row, column, and color on the LED matrix. The second diagram describes which pins on the processors lead to what output pads. The red numbers indicate the Arduino digital pin mapping. Every odd-numbered pin leads to the left (green) chip, and every even-numbered pin goes to the right (red) chip. The only exception to this rule of thumb is for pins 21-22 and 25-26 which lead to the closest analog pins.