AN2777 Freescale Semiconductor / Motorola, AN2777 Datasheet - Page 10

• Manufacturer Part Number: AN2777
• Description: Tango3 Monitor for the MC9S08RG60 MCU
• Manufacturer: Freescale Semiconductor / Motorola

RF Message Formats
DATARATE
Description: DATARATE allows the user to set the data rate for RF transmissions. This can be set to any
value with the range 500 bps to 10600 bps.
DATARATE value <return> — Set data rate to 'value'
SEND
Description: SEND allows the user to transmit an RF data packet from Tango3.
Data packets can be constructed from the following fields.
P — Preamble. The Preamble is a fixed format field that allows Romeo to detect the start of a message.
See the Romeo2 data sheet for details.
1 — sends a logic 1 Manchester encoded.
0 — sends a logic 0 Manchester encoded.
H — sends a logic 1 for one bit time (no Manchester encoding).
L — sends a logic 0 for one bit time (no Manchester encoding).
E — sends an End Of Message. This is a fixed format field that indicates the end of a message.
These fields follow the format defined in the Romeo2 data sheet. These fields can be sent in any
combination up to a maximum of 128 fields.
The P, 1, 0, and E fields follow the format defined in the Romeo2 data sheet.
SEND Command Examples
P1111111101010101E — Sends single message.
P1111111101010101EP1111111101010101E — Sends two back-to-back messages.
The H and L fields allow the user to send messages without Manchester encoding, or can be mixed with
Manchester encoded messages.
RF Message Formats
The Tango3 monitor allows the user to transmit messages using the data formats defined in the Romeo2
data sheet. There are two basic formats: messages with a header field and messages without a header
field.
10
Figure 7
shows some basic messages following these formats.
After a SEND command, the DATA pin is configured as an output pin set to
logic 0. This is intended to prevent spurious signals from occuring on the
data pin at the end of a message.
Tango3 Monitor for the MC9S08RG60 MCU, Rev. 0
NOTE
Freescale Semiconductor