Use RF in your next embedded application design! The receiver and transmitter boards (RLP & TLP 315) are cheap RF modules manufactured by Laipac Technologies. A pair costs $11.95 at SparkFun Electronics. The frequency on which the receiver and transmitter pair works is 315 MHz, UHF (Ultra High Frequency) frequency range.
Schematic for the RF Project, I made only one schematic instead of two to
save space (of course the TLP and RLP RF modules are connected to supply voltage
as well even if it is now shown on the schematic)
In the datasheet I read the speed can go up to 2400 baud, however I could get
it only working up to 1200 baud. In telecommunications and electronics, baud is
a measure of the “signaling rate” which is the number of changes to the
transmission media per second in a modulated signal. It is named after Émile
Baudot, the inventor of the Baudot code for telegraphy. For example: 250 baud
means that 250 signals are transmitted in one second. If each signal carries 4
bits of information then in each second 1000 bits are transmitted. This is
abbreviated as 1000 bit/s (this baud part was taken from Wikipedia).
Analyzing the received and transmitted signal on my HAMEG Oscilloscope
I used two ATMega32 microcontrollers, you can use any other with hardware
USART (Universal Synchronous Asynchronous Receiver Transmitter) capabilities
however I have few of them laying on my table. I had some problems with GNU C
and CodeVision C to receive data over the USART so I found an example code in
assembler how to transmit and receive data over the USART
Authored by
Sebastian Schmieg at
e-dsp, Added: 2 Apr 2006
http://www.e-dsp.com/how-to-build-your-own-wireless-receiver-and-transmitter-device-create-rf-in-your-embedded-application/
