I have made a RF sensor board with the following modules RFM12B 433MHz S2"" Trancievers.
The Transmitter is working because in Idle mode it draws about 5mA and when its working (transmitting) it draws 40mA so that should be OK.
By the way both modules are initialized correctly.
When I try to receive a byte "123" with the following macro's:
Send_Byte
Recieve_Byte
Its always returns 255 which indicates a timeout, That was strange I dit some further testing a I made a little program that checks the buffer of the recieving end, and the data form this buffer can tell me several things:
So this happend,char Check_Buffer ( char Timeout )
Puts the RF module in data mode and checks for an incoming data packet.
This function also accepts the reception of the values 0-null and 255 which is not available in the send_byte, send_string functions.
The timeout parameter specifies how many milliseconds to try and wait for a valid data buffer to be received.
A return value of 255 indicates a timeout.
A return value of 254 indicates that the length byte was received but no data.
A return value of 253 indicates that some data was received but the packet was incomplete.
A return value of 252 indicates a CRC checksum error meaning one or more of the received bytes is incorrect.
A return value between 1 and 8 indicates a valid reception and also indicates the number of data bytes received in the packet.
When the transmitter has been powered down (No transmission) the check_Buffer macro returns a 255 code which indicates a timeout which is understandable when I apply power to the transmitter the code 255 changes into 252 which indicates a CRC Checksum error. Why is that,
Has anybody an Idea on how to fix this.
Let me know,
Jordy Kleian



