Diff: spi.c

Revision:

0:4a8f916ef7b5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spi.c	Mon Jul 13 09:21:53 2015 +0000
@@ -0,0 +1,56 @@
+#include "spi.h"
+
+SPI device(SPI_MOSI, SPI_MISO, SPI_SCK);
+ 
+//SPI Init Code,visit SD Card/W25Q64/NRF24L01						  
+//SPI PIN Init
+void SPI_Init(void)
+{	 
+
+	//SPI2 clock frequence less than 36Mhz
+	SPI.frequency(36000000/256);
+	SPI_ReadWriteByte(0xff);//start transfer
+}   
+
+
+//SPI Speed Setting 
+//SpeedSet:0~7
+//SPI Speed = fAPB1/2^(SpeedSet+1)
+//APB1 clock usually is 36Mhz
+void SPI_SetSpeed(uint8_t SpeedSet)
+{
+	SpeedSet&=0X07;			//limit
+	SPI->CR1&=0XFFC7; 
+	SPI->CR1|=SpeedSet<<3;	//setting SPI speed
+	SPI->CR1|=1<<6; 		//SPI device enabled 
+} 
+
+
+//SPI readWrite a Byte
+//TxData:the data to write
+//return:the data read back
+u8 SPI_ReadWriteByte(uint8_t TxData)
+{		
+	u16 retry=0;				 
+	while((SPI->SR&1<<1)==0)		//waiting sending array is empty
+	{
+		retry++;
+		if(retry>=0XFFFE)return 0; 	//out of time quit
+	}			  
+	SPI->DR=TxData;	 	  		//send one byte
+	retry=0;
+	while((SPI->SR&1<<0)==0) 		//waiting received a byte
+	{
+		retry++;
+		if(retry>=0XFFFE)return 0;	//out of time quit
+	}	  						    
+	return SPI->DR;          		//return the data read	    
+}
+
+
+
+
+
+
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+