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9keypad, 1 introduction – Matrix Orbital VK204-25 Legacy User Manual

Page 37

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Description

This command will perform a single transaction on the 1-wire bus in
this order:

1. Bus Reset.
2. Transmit data onto the bus.
3. Receive data from the bus.

The number of bits to be transmitted and read must be specified for this
command to be successful.

NOTE

To determine what functions the device will respond to, consult the devices’ data

sheet.

1-Wire Flags

Bit

Description

7
6

Unused

5

(0 for future compatibility)

4
3

Add a CRC8 to the end of the transmitted data

2

(0 for future compatibility)

1

Assume last received byte is a CRC8 and validate it

0

Reset bus before transaction

1-Wire Error Codes

Code

Description

0x00

Success

0x01

Unknown 1-Wire Command

0x02

No devices on the bus

0x03

Fatal search error

Remembered

No

9

Keypad

9.1

Introduction

The VK204-25-USB supports up to a 25 key, matrix style, keypad and may be configured to allow key

presses to be automatically transmitted via USB. The VK204-25-USB also allows for auto-repeating key
presses, and remapping of all keypad character codes.

The connector is not keyed so the keypad will probably plug in either of two ways. The display will

not be damaged by reversing the connector. However, the keypad will generate a different ASCII character
mapping for each position. If the connector has fewer than 10 pins it should be centered on the display

Matrix Orbital

VK204-25-USB

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