Central Heating controller using the real time clock, PHY module for internet, 1-wire interface for temperature sensors, a system log and a configuration file
Dependencies: net 1-wire lpc1768 crypto clock web fram log
/media/uploads/andrewboyson/heating.sch
/media/uploads/andrewboyson/heating.brd
/media/uploads/andrewboyson/eagle.epf
Diff: fram/spi.c
- Revision:
- 13:2ca12dd42e91
- Parent:
- 5:82197a6997fd
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/fram/spi.c Tue Dec 04 14:40:20 2018 +0000 @@ -0,0 +1,55 @@ +#include "gpio.h" +#include "log.h" + +#define CS_DIR FIO0DIR(6) +#define CS_SET FIO0SET(6) +#define CS_CLR FIO0CLR(6) + +//SSP1 +#define CR0 (*((volatile unsigned *) 0x40030000)) +#define CR1 (*((volatile unsigned *) 0x40030004)) +#define DR (*((volatile unsigned *) 0x40030008)) +#define SR (*((volatile unsigned *) 0x4003000C)) +#define CPSR (*((volatile unsigned *) 0x40030010)) + +void SpiInit(void) +{ + //Configure + CR0 |= 7 << 0; //3:0 8 bit transfer + CR0 |= 0 << 4; //5:4 SPI + CR0 |= 0 << 6; //7:6 Mode 0 + CR0 |= 0 << 8; //divide by 1 + + //Set prescaler bps = PCLK / PS ==> PS = PCLK / bps ==> PS = 96/16 = 6 + CPSR = 6; //Bit 0 must be 0. 6 ==> 16 bps which is within the 20MHz allowed by the FRAM + + //Select the function of the ssel pin: P0.6 + CS_SET; //Deselect the output == CS = 1 + CS_DIR = 1; //Set the direction to 1 == output + + //Enable operation + CR1 |= 2; //Enable the SSP controller +} +void SpiChipSelect(int value) +{ + if (value) CS_SET; + else CS_CLR; +} +void SpiWrite(char byte) +{ + DR = byte; //This loads the next frame in the TX FIFO +} +int SpiBusy(void) +{ + return SR & 0x10; //bit 4 is BSY. This bit is 0 if the SSPn controller is idle, or 1 if it is currently sending/receiving a frame and/or the Tx FIFO is not empty. +} +char SpiRead(void) +{ + return DR & 0xFF; //This reads the oldest frame in the RX FIFO +} +char SpiTransfer(char byte) +{ + SpiWrite(byte); + while(SpiBusy()) /*spin until not busy, at 16 bits per us or 2 bytes per us should be only 48 operations*/; + return SpiRead(); +}