3. Exercise: Transmission in Synchronous Serial Mode

So far, the CC1200 has only been used in receive mode, either to measure the RSSI of a bit stream in synchronous serial mode or the receive a packet in FIFO mode. Now, let us experience the transmission mode. In this exercise we will transmit a bit stream from a sender to a receiver.

CC1200 will be set into synchronous serial mode. In this mode, CC1200 provides clock on one of the GPIO input lines. On the falling edge, data on the serial input line - normally on GPIO0 line - will be transferred on the media.

This task requires

• a ready BeagleBone Black equipped with the CC1200
• one TI Development Kit for the CC1200
• Smart RF Studio.

• connect the TI Development Kit to your computer and execute Smart RF Studio
• open the CC1200 panel and select “Symbolrate 38.4kbps, 2-GFSK, RX BW 100kHz, ETSI Standard (868MHz)” in the typical settings part
• press the button “Continuous TX” in the lower window.
• export all registers to a file.
• connect the BeagleBone Black to your computer and login as superuser.
• copy the export file from SmartRF Studio to the BeagleBone Black
• import the export file into your program and initialize the registers according the values of the export file.
• Read chapter 8.9 about the Synchronous Serial Mode of the CC1200 Users Guide and implement it.
• if the program is correctly compiled and linked start it.
• If this is the case bring SmartRF Studio in “Continuous RX” mode and start the transmitter. At SmartRF Studio the RSSI should increase. If switching off the transmitter, the RSSI should drop down.