113 lines
2.8 KiB
C
113 lines
2.8 KiB
C
#include <msp430.h>
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#include <stdint.h>
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#define READBUFFER_LEN 10
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#define WRITEBUFFER_LEN 10
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// this buffers store the the receved and send data
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unsigned char ReadBuffer[READBUFFER_LEN];
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unsigned char WriteBuffer[WRITEBUFFER_LEN];
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// the pointers are used to remenber the location it was on the buffer
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unsigned char *ReadBuffer_p = &ReadBuffer[0];
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unsigned char *WriteBuffer_p = &WriteBuffer[0];
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// if it finisched receving/sending a packet this wil become true
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bool NewPacket = false;
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enum {SLEEP, WRITE, READ} State;
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typedef enum {} PacketID_t; //TODO: add packet ids
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void Setup(void);
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int main(void)
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{
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WDTCTL = WDTPW + WDTHOLD; // Stop WDT
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P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
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P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
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Setup();
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State = SLEEP;
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while(1){
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while(!NewPacket){
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//TODO: add sleep mode
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}
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__disable_interrupt(); // don't want the interupt to destoy you beautiful packet
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NewPacket = false; // recet new packet flag
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uint8_t bytesReceved = ReadBuffer_p - &ReadBuffer[0];
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uint8_t data[READBUFFER_LEN];
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// copy data from the buffer used for the communication so it can receve the next packet
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memcpy(&data[0], &ReadBuffer[0], bytesReceved);
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__enable_interrupt(); // data is save
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switch (data[0]){
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case /* packet id */:
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/* read packet */
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break;
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}
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}
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}
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/*
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* Deze interrupt is beide voor RXIFG en TXIFG.
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* Dus vlaggetjes bekijken om te zien wat er gebeurd
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*/
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#pragma vector = USCIAB0TX_VECTOR
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__interrupt void USCIAB0TX_ISR(void)
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{
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if(IFG2 & UCB0TXIFG && State == WRITE){
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// Read data from I2C
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UCB0TXBUF = *WriteBuffer_p;
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WriteBuffer_p++;
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if(WriteBuffer_p > &WriteBuffer[WRITEBUFFER_LEN]){
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State = SLEEP;
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NewPacket = true;
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}
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}else if(IFG2 & UCB0RXIFG && State == READ){
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// Write data to I2C
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*ReadBuffer_p = UCB0RXBUF;
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ReadBuffer_p++;
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if(ReadBuffer_p > &ReadBuffer[READBUFFER_LEN]){
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State = WRITE;
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}
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}
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}
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/*
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* Hier krijgen we de start/stop condities
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*/
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#pragma vector = USCIAB0RX_VECTOR
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__interrupt void USCIAB0RX_ISR(void)
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{
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if(UCB0STAT & UCSTTIFG){
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// start signaal ontvangen
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State = READ;
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// reset pointers
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WriteBuffer_p = &WriteBuffer[0];
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ReadBuffer_p = &ReadBuffer[0];
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}else if(UCB0STAT & UCSTPIFG){
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// stop signaal, klaar met transactie
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State = SLEEP;
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NewPacket = true;
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}
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// Clear interrupt flags
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UCB0STAT &= ~(UCSTPIFG + UCSTTIFG);
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}
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void Setup(void){
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__disable_interrupt();
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UCB0CTL1 |= UCSWRST; // reset
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UCB0CTL0 = UCMODE_3 + UCSYNC; // I2C Slave, synchronous mode
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UCB0I2COA = 0x48; // eigen slave adres is 048h
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UCB0CTL1 &= ~UCSWRST; // reset uit
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UCB0I2CIE |= UCSTPIE + UCSTTIE; // detectie voor start en stop
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IE2 |= UCB0RXIE | UCB0TXIE; // interrupts aan
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__enable_interrupt();
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}
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