Help with transmitter using resonator and PIC

[Lupe]

transmitter saw resonator

Hello all, I have some general questions if someone can help me out. I have a supply of receivers and transmitters that I would like to use in my project using an Atmel AVR micro. The receiver uses a KESRX01 IC and a PIC micro. I would like to disconnect the Data out line from the receiver and connect it to my AVR micro. I can currently read the data from the transmitter by connecting the receiver to my computers RS232 port. I cannot make sense of the data but am not to concerned right now as my main problem is the transmitter. The transmitter uses a PIC micro also with a SAW resonator operating at 295.05 MHZ. My problem is how can I use this transmitter without redesigning the whole thing and/or would it be easier to find a trasmitter that works with my frequency and use it instead. I am sure I cannot just take the PIC micro out of the transmitter circuit and expect to feed it with my own data from my micro. This is my 3rd post in various forums, I have not gotten to much response so I plead to you guys with more experience for direction, any help, links, complaints, anything would help . I would even give you a receiver already designed in a circuit board with a PIC micro in it. If you have better electronics knowledge than me and program PIC's you could probably program your own PIC with your own code. Thanks Lupe

 

[Mr.MEB]

saw resonator by transmitter design

What is it the model of the PIC? If it's an rfPIC it would be hard to modify the rf circuits, but if it's a simple micro that makes encoding(i.e. manchester) and communicate via RS-232, it would be no problem to modify this circuit and isolate the PIC, in order to use with an other micro (AVR).
But what's the point in modifying the circuit? The PIC is there to facilitate rf interfacing, so try connecting your AVR with serial comm.

 

[Lupe]

using avr as transmitter

Hello and thanks for your reply, the receiver uses a PIC16C58B and the transmitter uses a PIC16C54C. I am having trouble understanding how to use the transmitter, because it uses a an RFM R02100 saw resonator at 295.05MHZ. I can connect my receiver through and RR232 driver and connect to my PC. But how can I use this transmitter and connect it to my micro with my program. I am not familiar with PIC's and faintly learning how to use AVR's , I have an STK500 and several AVR's that I would like to use programmed in either assembly or Bascom.

 

[Mr.MEB]

rs232 transmitter pic

First, to make a RS-232 connection you will need a little bit hardware to convert -12V +12V digital 1-0 level to microcontr. compatible CMOS-TTL : 0V 5V.
For this you need either a chip like max232 -233 or 2 transistors.
For the comm, you have probably an hardware UART peripheral in your microcontroller which will be of great help. Then you should look at the specs of the modules to find the communication protocol (if any).
Look at his link, there are plenty creative projects made with STK500 and that incorporate RS 232 communication:
https://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/

 

[Lupe]

resonator+pic

Hello, and thanks for your response. Here is my problem. I don't know how I can use this transmitter in my project. The transmiiter use an RFM-R02100 saw resonator with a PIC microcontroller. I don't want to use the PIC micro. I prefer to use an Atmel AVR. Can anyone help me to understand how I can do this. I have looked at the data sheet for the resonator, and there is a basic schematic of a transmitter. Can someone explain the modulation input signal and how can this be achieved with a AVR micro connected to it. Is it as simple as connecting my micro input signal to this point (the modulation input signal). My transmitter appears to be like the example schematic in that it also uses an MPSH10 transistor. Would it help if I remove the PIC from the transmitter and try and layout a schematic of the transmitter. Forgive me for being so set on using these 295.05 MHZ transmitters and receivers, its just that as a hobbyist I don't have the knowledge and time to design my own and I would hate to not use plenty of receivers and transmitters that are already designed and working. I would just like to use them in my projects with AVR micros. Any help is appreciated. Thanks, lupe.