Assignment 11: Wired and Wireless Communications
For this assignment, I added a 2-way FM radio tranceiver module (Radiometrix BiM2-433-64) to the SAK/hoarder baseboard in order to able to wirelessly transfer data in realtime from the system to a laptop.The baseboard was originally fabbed with a space for the tranceiver, which takes the same TX/RX signals from the PIC16F877 used for the serial port.
On the receiver end, I connected another BiM2 module to a serial connector to be used as an interface to my laptop. This tranceiver module was powered by hacking the USB port of the laptop via a standard USB slave connector. Inverters were used to drive the TX/RX lines between the tranceiver and the laptop. Here's a picture of the completed receiver unit (with serial and usb power connectors) for the laptop.
The completed system works very well even without attaching an antenna to the tranceiver, as long as the system is in close proximity to the receiver. Theoretically the tranceivers can still work up to 200 meters apart with unobstructed direct line of view using a whip antenna.