Student project help needed.
For a student project I am looking forward to have opinion from you. I want to design et of two small electronic devices, we can call them device A the main device and device B.. If device A becomes out of range of device B, device A should start beeping. I would like both devices to be as small as possible and as thin as possible. Range should also be configurable from 10 feet to 50 feet max.
Best Regards
Dani
Well, the easiest way that pops in my mind to do so is: design a simple RF transmitter and a simple receiver, working at a fixed frequency of your choice. On the receiver site, rectify and amplify the signal, then feed it to a comparator: when the signal drops below a certain level, use the comparator output to do something.
I agree with that, and that is the simplest thing to do.
Any reference design or helping material available?
Thanks for answering so quick.
If you can please refer me to some sample working project design of such circuit that would be very helpful.
Designing and tunning the rf circuit seems to be little tough for me. What would you say about using a ready made rf transceiver module with rs232 or other interface to microcontroller.
Best Regards
Dani
as far as i know, the ready made modules usually come with features like automatic gain compensation and stuff ... what you need is to determine the strength of the raw signal ... this would be difficult with ready made modules ...
If you are allowed to use a commercial module and a microcontroller, then you can purchase some XBee modules from Digi.
They come with TTL-level serial port, integrated RSSI measurement and software-configurable RF power. Working frequency is 2.45 GHz. If you configure the modules with 802.15.4 firmware, doing what you need should be really straightforward, you only have to study the manual and write some lines of code
Price should be 15-20? + VAT each.