User's Manual

Author: Radio Group
Date: February 11
th
, 2014
Revision: March 4
th
, 2015
Subject: Integration Guide – Mizar Radio Module 915 MHz
Page 8 of 10
decodes it and sends decoded data to the Host by means of the UART interface. Only valid demodulated
data packets are sent to the Host.
Transmission State
This state is enabled from the host when it needs to transmit data. The transmission state is enabled
sending a data packet to the radio module over the UART interface. The microcontroller in the radio
module checks for the integrity of the data packet and enables the transceiver to modulate and transmit to
the RF interface, preceded by a short preamble burst. Radio module exits automatically from this state
when the complete packet has been transmitted, and returns to the receive state.
Radio module operates in CSMA-CA (carrier sense multiple access – collision avoidance) : transmission is
enabled when the RF channel is not busy by the use of a “carrier detect” function. Radio module accesses
the channel in a fair way using a backoff algorithm.
Interface description (pinout reference)
UART 2-pin interface, used to exchange data from the Host:
DATA_OUT (output pin) : transmits data to Host.
DATA_IN (input pin) : receives data from Host.
CD# – (output pin) Carrier Detect :
When radio is in receive mode, this pin signals the presence of RF carrier.
IDLE - (input pin) :
A high level on this pin forces the radio module in Idle State.
RESET (input pin) :
A low level on this pin resets the radio module.
VCC and GND :
Radio module power supply.
RF Port :
Radio Frequency Connector for the antenna.