main_ezlink.c.svn-base

Si4432-T-B1版本资料.rar

/*
** ============================================================================
**
** FILE
**  main.c
**
** DESCRIPTION
**  This is the main file of the project.	    
**  HW platform EZLink module with C8051F93x Silabs MCU 
**
** CREATED
**  Silicon Laboratories Hungary Ltd
**
** COPYRIGHT
**  Copyright 2009 Silicon Laboratories, Inc.  
**	http://www.silabs.com
**
** ============================================================================
*/


								/* ======================================================== *
								 *									INCLUDE					*
							 	 * ======================================================== */


#include "C8051F930_defs.h"
#include "compiler_defs.h"
#include <string.h>

							/* ================================================================ *
							 * C8051F930 Pin definitions for EZLink	platform			        *
							 * 					(using compiler_def.h macros) 					*
							 *	=============================================================== */	

SBIT (NSS, SFR_P1, 3);
SBIT (NIRQ, SFR_P0, 6);
SBIT (SDN, SFR_P0, 1);
SBIT (RX_LED, SFR_P2, 0);      
SBIT (TX_LED, SFR_P1, 6);      
SBIT (PB,     SFR_P0, 7);       


								/* ======================================================== *
								 *							Function PROTOTYPES				* 
								 * ======================================================== */
//MCU initialization
void MCU_Init(void);
//SPI functions						
void SpiWriteRegister (U8, U8);
U8 SpiReadRegister (U8);


void main(void)
{
	U8 ItStatus1,ItStatus2;
	U16 delay;
	U8 length,temp8;
	U8 payload[10];

	//Initialize the MCU: 
	//	- set IO ports for the Software Development board
	//	- set MCU clock source
	//	- initialize the SPI port 
	//	- turn off LEDs
	MCU_Init();
							/* ======================================================== *
							 *						Initialize the Si4431 ISM chip		* 
							 * ======================================================== */
	//Turn on the radio by pulling down the PWRDN pin
	SDN = 0;
	//Wait at least 15ms befory any initialization SPI commands are sent to the radio
	// (wait for the power on reset sequence) 
	for (temp8=0;temp8<15;temp8++)
	{
		for(delay=0;delay<10000;delay++);
	}	 
	//read interrupt status registers to clear the interrupt flags and release NIRQ pin
	ItStatus1 = SpiReadRegister(0x03);														//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);														//read the Interrupt Status2 register

	//SW reset   
   	SpiWriteRegister(0x07, 0x80);															//write 0x80 to the Operating & Function Control1 register 
	//wait for chip ready interrupt from the radio (while the nIRQ pin is high)
	while ( NIRQ == 1);  
	//read interrupt status registers to clear the interrupt flags and release NIRQ pin
	ItStatus1 = SpiReadRegister(0x03);														//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);														//read the Interrupt Status2 register
						
							/*set the physical parameters*/
	//set the center frequency to 915 MHz
	SpiWriteRegister(0x75, 0x75);															//write 0x75 to the Frequency Band Select register             
	SpiWriteRegister(0x76, 0xBB);															//write 0xBB to the Nominal Carrier Frequency1 register
	SpiWriteRegister(0x77, 0x80);  															//write 0x80 to the Nominal Carrier Frequency0 register
	
	//set the desired TX data rate (9.6kbps)
	SpiWriteRegister(0x6E, 0x4E);															//write 0x4E to the TXDataRate 1 register
	SpiWriteRegister(0x6F, 0xA5);															//write 0xA5 to the TXDataRate 0 register
	SpiWriteRegister(0x70, 0x2C);															//write 0x2C to the Modulation Mode Control 1 register

	//set the Tx deviation register (+-45kHz)
	SpiWriteRegister(0x72, 0x48);															//write 0x48 to the Frequency Deviation register 


								/*set the modem parameters according to the exel calculator(parameters: 9.6 kbps, deviation: 45 kHz, channel filter BW: 102.2 kHz*/
	SpiWriteRegister(0x1C, 0x1E);															//write 0x1E to the IF Filter Bandwidth register		
	SpiWriteRegister(0x20, 0xD0);															//write 0xD0 to the Clock Recovery Oversampling Ratio register		
	SpiWriteRegister(0x21, 0x00);															//write 0x00 to the Clock Recovery Offset 2 register		
	SpiWriteRegister(0x22, 0x9D);															//write 0x9D to the Clock Recovery Offset 1 register		
	SpiWriteRegister(0x23, 0x49);															//write 0x49 to the Clock Recovery Offset 0 register		
	SpiWriteRegister(0x24, 0x00);															//write 0x00 to the Clock Recovery Timing Loop Gain 1 register		
	SpiWriteRegister(0x25, 0x24);															//write 0x24 to the Clock Recovery Timing Loop Gain 0 register		
	SpiWriteRegister(0x1D, 0x40);															//write 0x40 to the AFC Loop Gearshift Override register		
	SpiWriteRegister(0x2A, 0x20);															//write 0x20 to the AFC Limiter register		
	
	//set the Modem test register 
	SpiWriteRegister(0x56, 0xC1);															//write 0xC1 to the Modem test register


							/*set the packet structure and the modulation type*/
	//set the preamble length to 5bytes 
	SpiWriteRegister(0x34, 0x0C);															//write 0x0C to the Preamble Length register
	//set preamble detection threshold to 20bits
	SpiWriteRegister(0x35, 0x2A); 															//write 0x2A to the Preamble Detection Control  register

	//Disable header bytes; set variable packet length (the length of the payload is defined by the
	//received packet length field of the packet); set the synch word to two bytes long
	SpiWriteRegister(0x33, 0x02);															//write 0x02 to the Header Control2 register    
	
	//Set the sync word pattern to 0x2DD4
	SpiWriteRegister(0x36, 0x2D);															//write 0x2D to the Sync Word 3 register
	SpiWriteRegister(0x37, 0xD4);															//write 0xD4 to the Sync Word 2 register

	//enable the TX & RX packet handler and CRC-16 (IBM) check
	SpiWriteRegister(0x30, 0x8D);															//write 0x8D to the Data Access Control register
	//Disable the receive header filters
   	SpiWriteRegister(0x32, 0x00 );															//write 0x00 to the Header Control1 register            
	//enable FIFO mode and GFSK modulation
	SpiWriteRegister(0x71, 0x63);															//write 0x63 to the Modulation Mode Control 2 register

											/*set the GPIO's according to the RF switch */
   	SpiWriteRegister(0x0C, 0x12);															//write 0x12 to the GPIO1 Configuration(set the TX state)
	SpiWriteRegister(0x0D, 0x15);															//write 0x15 to the GPIO2 Configuration(set the RX state) 

											/*set the non-default Si4431 registers*/
	//set the VCO and PLL
	SpiWriteRegister(0x57, 0x01);															//write 0x01 to the Chargepump Test register													
	SpiWriteRegister(0x59, 0x00);															//write 0x00 to the Divider Current Trimming register 	
	SpiWriteRegister(0x5A, 0x01); 															//write 0x01 to the VCO Current Trimming register
	//set  cap. bank
	SpiWriteRegister(0x09, 0xD7);															//write 0xD7 to the Crystal Oscillator Load Capacitance register

	/*enable receiver chain*/
	SpiWriteRegister(0x07, 0x05);															//write 0x05 to the Operating Function Control 1 register
	//Enable two interrupts: 
	// a) one wich shows that a valid preamble received:'ipreaval'
	// b) second shows if a sync word received:'iswdet'
	SpiWriteRegister(0x05, 0x00); 															//write 0x00 to the Interrupt Enable 1 register
	SpiWriteRegister(0x06, 0xC0); 															//write 0xC0 to the Interrupt Enable 2 register
	//read interrupt status registers to release all pending interrupts
	ItStatus1 = SpiReadRegister(0x03);														//read the Interrupt Status1 register
	ItStatus2 = SpiReadRegister(0x04);														//read the Interrupt Status2 register


	/*MAIN Loop*/
	while(1)
	{
		//Poll the port pins of the MCU to figure out whether the push button is pressed or not
		if(PB == 0)
		{	
			//Wait for releasing the push button
			while( PB == 0 );
			//disable the receiver chain (but keep the XTAL running to have shorter TX on time!)
			SpiWriteRegister(0x07, 0x01);													//write 0x01 to the Operating Function Control 1 register			

			//turn on the LED to show the packet transmission
			TX_LED = 1; 																			

			/*SET THE CONTENT OF THE PACKET*/
			//set the length of the payload to 8bytes	
			SpiWriteRegister(0x3E, 8);														//write 8 to the Transmit Packet Length register		
			//fill the payload into the transmit FIFO
			SpiWriteRegister(0x7F, 0x42);													//write 0x42 ('B') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x55);													//write 0x55 ('U') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x54);													//write 0x54 ('T') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x54);													//write 0x54 ('T') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x4F);													//write 0x4F ('O') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x4E);													//write 0x4E ('N') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x31);													//write 0x31 ('1') to the FIFO Access register	
			SpiWriteRegister(0x7F, 0x0D);													//write 0x0D (CR) to the FIFO Access register	

			//Disable all other interrupts and enable the packet sent interrupt only.
			//This will be used for indicating the successfull packet transmission for the MCU
			SpiWriteRegister(0x05, 0x04);													//write 0x04 to the Interrupt Enable 1 register	
			SpiWriteRegister(0x06, 0x00);													//write 0x00 to the Interrupt Enable 2 register	
			//Read interrupt status regsiters. It clear all pending interrupts and the nIRQ pin goes back to high.
			ItStatus1 = SpiReadRegister(0x03);												//read the Interrupt Status1 register
			ItStatus2 = SpiReadRegister(0x04);												//read the Interrupt Status2 register

			/*enable transmitter*/
			//The radio forms the packet and send it automatically.
			SpiWriteRegister(0x07, 0x09);													//write 0x09 to the Operating Function Control 1 register

			/*wait for the packet sent interrupt*/
			//The MCU just needs to wait for the 'ipksent' interrupt.
			while(NIRQ == 1);
			//read interrupt status registers to release the interrupt flags
			ItStatus1 = SpiReadRegister(0x03);												//read the Interrupt Status1 register
			ItStatus2 = SpiReadRegister(0x04);												//read the Interrupt Status2 register

			//wait a bit for showing the LED a bit longer
			for(delay = 0; delay < 10000;delay++);
			//turn off the LED
			TX_LED = 0; 
			
			//after packet transmission set the interrupt enable bits according receiving mode
			//Enable two interrupts: 
			// a) one wich shows that a valid preamble received:'ipreaval'
			// b) second shows if a sync word received:'iswdet'
			SpiWriteRegister(0x05, 0x00); 													//write 0x00 to the Interrupt Enable 1 register
			SpiWriteRegister(0x06, 0xC0); 													//write 0xC0 to the Interrupt Enable 2 register
			//read interrupt status registers to release all pending interrupts
			ItStatus1 = SpiReadRegister(0x03);												//read the Interrupt Status1 register
			ItStatus2 = SpiReadRegister(0x04);												//read the Interrupt Status2 register

			/*enable receiver chain again*/
			SpiWriteRegister(0x07, 0x05);													//write 0x05 to the Operating Function Control 1 register				
		}
			
		//check whether interrupt occured
		if( NIRQ == 0 )
		{
			//read interrupt status registers to release all pending interrupts
			ItStatus1 = SpiReadRegister(0x03);												//read the Interrupt Status1 register
			ItStatus2 = SpiReadRegister(0x04);												//read the Interrupt Status2 register

			//check whether preamble is detected
			if( (ItStatus2 & 0x40) == 0x40 )
			{//preamble is detected
				//wait for the synch word interrupt with timeout -- THIS is the proposed SW workaround
				//start a timer in the MCU and during timeout check whether synch word interrupt happened or not
				delay = 0;
				do {
					delay++;
				} while((delay < 20000) && (NIRQ == 1));	
				
				
				//check whether the synch word interrupt is detected
				if( NIRQ == 0)
				{//synch word detected correctly
					//read interrupt status registers to release all pending interrupts
					ItStatus1 = SpiReadRegister(0x03);										//read the Interrupt Status1 register
					ItStatus2 = SpiReadRegister(0x04);										//read the Interrupt Status2 register
				
					//Enable two interrupts: 
					// a) one which shows that a valid packet received: 'ipkval'
					// b) second shows if the packet received with incorrect CRC: 'icrcerror' 
					SpiWriteRegister(0x05, 0x03); 											//write 0x03 to the Interrupt Enable 1 register