www.pudn.com > CC2420_TRX.rar > hal_rf_set_channel.c

/******************************************************************************************************* 
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 *      ***        ***                                                                                 * 
 *      ***   +++   ***                                                                                * 
 *      ***   + +   ***                                                                                * 
 *      ***   +                        CHIPCON HARDWARE ABSTRACTION LIBRARY FOR THE CC2420             * 
 *      ***   + +   ***                             CC2420 channel selection                           * 
 *      ***   +++   ***                                                                                * 
 *      ***        ***                                                                                 * 
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 * The Chipcon Hardware Abstraction Library is a collection of functions, macros and constants, which  * 
 * can be used to ease access to the hardware on the CC2420 and the target microcontroller.            * 
 *                                                                                                     * 
 * This file contains a function that allows you to switch radio channels on the CC2420.               * 
 *                                                                                                     * 
 * EXAMPLE OF USAGE:                                                                                   * 
 *     // Turn off RX...                                                                               * 
 *     DISABLE_GLOBAL_INT();                                                                           * 
 *     FASTSPI_STROBE(CC2420_SRFOFF);                                                                  * 
 *     ENABLE_GLOBAL_INT();                                                                            * 
 *                                                                                                     * 
 *     // ... switch to the next channel in the loop ...                                               * 
 *     halRfSetChannel(channel++);                                                                     * 
 *     if (channel == 27) channel = 11;                                                                * 
 *                                                                                                     * 
 *     // ... and go back into RX                                                                      * 
 *     DISABLE_GLOBAL_INT();                                                                           * 
 *     FASTSPI_STROBE(CC2420_SRXON);                                                                   * 
 *     ENABLE_GLOBAL_INT();                                                                            * 
 ******************************************************************************************************* 
 * Compiler: AVR-GCC                                                                                   * 
 * Target platform: CC2420DB, CC2420 + any MCU with very few modifications required                    * 
 ******************************************************************************************************* 
 * Revision history:                                                                                   * 
 * $Log: hal_rf_set_channel.c,v $ 
 * Revision 1.3  2004/03/30 14:59:35  mbr 
 * Release for web 
 *  
 * 
 * 
 * 
 *******************************************************************************************************/ 
#include  
 
 
 
 
//------------------------------------------------------------------------------------------------------- 
//	void halRfSetChannel(UINT8 Channel) 
// 
//	DESCRIPTION: 
//		Programs CC2420 for a given IEEE 802.15.4 channel.  
//		Note that SRXON, STXON or STXONCCA must be run for the new channel selection to take full effect. 
// 
//	PARAMETERS: 
//		UINT8 channel 
//			The channel number (11-26) 
//------------------------------------------------------------------------------------------------------- 
void halRfSetChannel(UINT8 channel) { 
	UINT16 f; 
	 
	// Derive frequency programming from the given channel number 
	f = (UINT16) (channel - 11); // Subtract the base channel  
	f = f + (f << 2);    		 // Multiply with 5, which is the channel spacing 
	f = f + 357 + 0x4000;		 // 357 is 2405-2048, 0x4000 is LOCK_THR = 1 
	 
    // Write it to the CC2420 
	DISABLE_GLOBAL_INT(); 
	FASTSPI_SETREG(CC2420_FSCTRL, f); 
	ENABLE_GLOBAL_INT(); 
 
} // rfSetChannel