User's Manual

Viewsonic Tweety RF Remote Rev 2.9A November 05, 2001
Universal Electronics Inc. Confidential
Page 20 of 63
3.4.1 Definitions
Stuck Key Time-out
After any key is pressed continuously for 60 seconds, the remote will stop sending data packets and turn off RF transmission to conserve battery life.
Transmission can begin again, after all keys are released and key is pressed.
Stuck-Key Data Packet
Byte10 Byte09 Byte08 Byte07 Byte06 Byte05 Byte04 Byte03 Byte02 Byte01 Byte0
(MSB)
0x0F 0x0F 0x0F 0x0F 0x55 0x55
0-0x63
(0-99
decimal)
0x00 0xFC
(LSB)
0xYY
Sync Bytes Preamble
Device
Number
Dev Addr /
Status
X Coord
Y Coord /
ScanCode
CheckSum
32 bits 16 bits 8 bits 8 bits 8 bits 8 bits 8 bits
How and When the Stuck-Key code is sent:
The Stuck-Key Code Data Packet will be sent:
 After two data packets of the Make Code of the detected key press, <K1> say, have been sent out. If this (same) key, <K1>, is still being held down for more
than 60 seconds, then two data packets of Stuck-Key code will be sent with 10 ms delay time interval between data packets. A Make Code data packet of the
same key sent every 70 ms time interval during this 60 seconds stuck key condition.

For the pointing device, after sending out the X-Coord and Y-Coord continuously up to 2 minutes which is the time to be considered as stuck key timeout for
pointing device. Two data packets of Stuck Code will be sent.

Two data packets of Sleep Code will be sent following the Stuck Code data packet. The RF Transmitter will then be turned OFF.
Sleep Mode
This is the idle state of the micro-controller when it draws the least amount of current. Upon entering the idle mode, the remote will transmit a unique byte
(FD) to notify the receiver that it is entering into the sleep mode.