I just bought the RF Link - 4800bps - 315MHz (SKU#: WRL-07816) and I am trying to send an analog signal wirelessly. If I understand what I am reading in the specs, I need to convert the analog signal to digital then transmit it. Is that right?
Also once the signal has been transmitted what sort of data output can I expect?
I have a very basic understanding of electronics from college. Any help would be greatly appreciated! Are there any tutorials or examples I can look at?
Thanks!
Tell us a little more about what you want to do.
What type of analog signal and how often will you need to send the data? Reading a DC level periodically and sending the voltage level is easy. Sending audio or data that requires a high sample rate to track changes is much more difficult.
No it’s not audio. It’s just an analog signal from the MaxBotics Ultrasonic sensor. I just want to read it periodically and then send it.
I believe that the Maxbotics reports the distance in tenths of an inch in a byte value (0…255). I think the unit can report continuously (which you don’t want) and when you query it (which you do want).
Take a look at this thread which shows one way to transmit and receive the data…
I would suggest getting a PICAXE 08M that Sparkfun is selling. http://www.sparkfun.com/commerce/produc … ts_id=8308
I have never used a PICAXE myself but it looks like the PICAXE 08M supports 10-bit ADC and also supports a 4800 baud UART (using the SERTXD command). It is also very tiny! Only 8 pins!
Just use the ADC to read the AN pin of the MaxBotics ultrasonic sensor, use the Vcc/512 per inch formula to convert to distance in inches. The max distance of the ultrasonic sensor is 254 inches so your distance in inches can be represented in 1 byte. Use UART at a 4800 baud (or lower) to transmit the distance via your wireless transmitter. I would suggest sending a starting byte and a checksum byte with your distance byte for data assurance.
Good luck!
Nullz