Radio transmitters and receivers
Radio circuits used to frighten me but now with the introduction of low cost modules the radio novice like myself can transmit data easily.
This section details the use of the 418 MHz Radio Transmitter and Receiver Modules (RT1-418 and RR3-418). They do not need a license to operate and there are many varieties available. The transmitters only have 3 connections, 2 power supply and one data input, the transmitting aerial is incorporated on the unit. The receiver has 4 connections, 2 power supply, 1 aerial input and 1 data output. The receiving aerial only needs to be a piece of wire about 25cm long.
The basic circuit diagram of the radio system is shown in Figure 12.1.
Figure 12.1 Radio data transmission system ...