EA 9777-2USB ELECTRONIC ASSEMBLY, EA 9777-2USB Datasheet - Page 9

• Manufacturer Part Number: EA 9777-2USB
• Description: Display Development Tools Eval Board USB For Windows OS
• Manufacturer: ELECTRONIC ASSEMBLY

Specifications of EA 9777-2USB

• Product Category: Display Development Tools
• Rohs: yes
• Product: Evaluation Boards
• Tool Is For Evaluation Of: 3.2 in TFT Displays
• Interface Type: USB
• Operating Supply Voltage: 3.3 V, 5 V
• Description/function: Evaluation Board for USB
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: - 20 C
• Viewing Area: 3.2 in

ELECTRONIC ASSEMBLY reserves
the right to change specifications
without prior notice. Printing and
typographical
EXTERNAL KEYBOARD
A keyboard (anything from individual keys to a 8x8 matrix keyboard) can be connected to the I/O- ports.
The command ‘ESC Y M n1 n2 n3’ defines the count of input lines (n1=1..8) and output lines (n2=1..8).
n3 set debounce function with 10ms steps (n3=0..15). Please note that count of digital input and output
lines will be reduced while connecting an external keyboard at the same port.
Each key is connected with 1 output and 1 input. All inputs are terminated with a 20..50kΩ pull-up
resistor. For double-keytroke function decoupling of outputs is necessary. For that please use schottky
diodes (e.g. BAT 46).
Transmitting the keystrokes
At each keystroke, the associated key number (1..64) is transmitted or if a corresponding Matrix-
Macro is defined, Matrix-Macro will be started. The release of the key is not transmitted. If the release
of the key is to be transmitted as well, this can be done by defining Matrix-Macro no. 0.
(see page 17: Responses of EA eDIP)
Calculating of key numbers:
Key_number = (output-1) * count_of_inputs + input (output = MOx, input = MIx).
Examples
- 2x2 matrix: Command ‘ESC Y M 2 2 ..’ defines the 2x2 matrix. Keypad will need input lines MI1, MI2
- 1x4 matrix: Command ‘ESC Y M 1 4 ..’ defines the 1x4 matrix. Keypad will need output lines
- 4x0 matrix: Using one single output only (physically 4x1 Matrix), all keys can switch to GND. So no
- 4x4 matrix: Command ‘ESC Y M 4 4 ..’ defines the 4x4 matrix. Keypad will need input lines MI1..MI4
.
2x2 Matrix
errors
and output lines MO1, MO2. Output lines are decoupled by diodes; this is for double
keystrokes necessary. 6 input and 6 output lines remain free for other requirements.
MO1..MO4 and a single input line MI1. With that connection 7 input and 4 output lines
remain free for other requirements.
output line is necessary and comman ‘ESC Y M 4 0 ..’ defines 4 input lines onyl. With that
connection 4 input and 8 output lines remain free for other requirements.
and output lines MO1..MO4. Output lines are decoupled by diodes; this is for double
keystrokes necessary. 4 input and 4 output lines remain free for other requirements.
reserved.
1x4 Matrix
4x0 Matrix
4x4 Matrix
EA eDIPTFT32-A
Page 9