P11209: WOOCS: Long-Range RF Module

11209 Long Range RF Quick Start Guide

This document is intended to get future senior design teams started with using the 11209 RF modules for serial communication between two endpoints.

Setting Up the Devices

The entire code project for the device's firmware can be found in this zip file:


Extract the files and open the "\ide\rfusb_cc1111\iar" folder and double-click "rf_modem.eww" (must have IAR embedded workbench for 8051 installed). This will open the whole project up (basically a slightly modified version of the rf modem example available from TI)

The final boards that we produced have the debug interface pins wired incorrectly, making it impossible to connect them to a CC-Debugger for programming. For this reason, we have created a customized cable for use with the CC-Debugger. It looks like a birds nest but it gets the job done. The embedded firmware requires one device to be named "DEVICE_1" and the other "DEVICE_2" which must be hard coded into the firmware. This can be found in the main "rf_modem.c" file under the "appSelectRole" function. Once the project is recompiled (press F7), a file called rf_modem.hex is created in the same directory as the project. Use SmartRF Flash Programmer and the CC-Debugger to program a device with this firmware image. Be sure to power up the device first, either by using the WOCCS battery unit or a DC power supply set to 3.3V and limited current to 500mA. The devices cannot get power over USB.

There is a large block of code that is commented out in the appReceiverTask() function - this is something we attempted to do to get our boards to interface with a test-bench created by another design team, but it was never very successful. Channel selection is also something that we had a hard time actually setting from the PC side of things, so the devices are hard-coded at channel 0 (902 MHz). This can be changed at the top of the program by modifying the compiler defined constant "MRFI_CHANNEL".

Once two devices are programmed as device 1 and 2, they can be used to send serial data between two USB ports. The driver for the usb modem devices can be found in the "Driver" folder in the above zip file, or in the USB Firmware Library and Examples (link above) from TI. You then have to configure the port settings in the Device Manager to use 38400 data rate, no parity, hardware flow control, 8 data bits, 1 stopbit.

We had the most success using TeraTerm as our terminal emulation program for simply testing that a link exists. It is also possible to send entire text files via a Windows command line (cmd.exe) by typing "copy file.txt com2", or whichever com port is configured. Note that this cannot be done while TeraTerm is connected to the com port (you will get an Access Denied error).

From that point, custom software can be written to perform just about any task necessary using the device. For any questions contact mattcrev@gmail.com