1 | #include <msp430.h>
|
2 | #include "msp430fr_i2c_functions.h"
|
3 |
|
4 | unsigned char TXData = 0; // Pointer to TX data
|
5 | unsigned char TXByteCtr; // Bytecounter for data to be send
|
6 | unsigned char RXData[4]; // Bytearray for received bytes
|
7 | unsigned int RXByteCtr; // Bytecounter for data to be received
|
8 |
|
9 |
|
10 | /*void clear_rx_buffer(void)
|
11 | {
|
12 | int i=4; // size of RXData
|
13 | for (i; i > 0; i--)
|
14 | {
|
15 | RXData[i] = 0;
|
16 | }
|
17 | }*/
|
18 |
|
19 |
|
20 | void init_i2c(void)
|
21 | {
|
22 | P1OUT |= BIT6 + BIT7;
|
23 | P1REN |= BIT6 + BIT7;
|
24 | //UCB0IE |= UCTXIE0 + UCRXIE0 + UCNACKIE; //transmit and NACK interrupt enable*/
|
25 |
|
26 | UCB0CTL1 |= UCSWRST; // Activate the reset status
|
27 | UCB0CTL1 &= ~UCA10;
|
28 | UCB0CTL1 &= ~UCSLA10;
|
29 | UCB0CTLW0 |= UCMODE_3 + UCMST + UCSYNC; // I2C master mode
|
30 | UCB0BRW = 0x0008; // Set baudrate = SMCLK / 8 --> (1MHz/8 = 125kHz)
|
31 | UCB0CTLW1 = UCASTP_2; // Autom. STOP assertion
|
32 | P1SEL1 |= 0xC0; // Configure I2C pins
|
33 | // P1SEL_7 = 1;
|
34 | // P1SEL_6 = 1;
|
35 |
|
36 | UCB0CTL1 ^= UCSWRST; // Deactivate the reset status
|
37 | UCB0IE |= UCTXIE; // Enable transmit interrupt (TX-Interrupt)
|
38 | UCB0IE |= UCNACKIE; // Enable NACK interrupt
|
39 | UCB0IE |= UCRXIE; // Enable receive interrupt (RX-Interrupt)
|
40 | UCB0IE |= UCBCNTIE; // Enable Byte Counter interrupt
|
41 | UCB0IE |= UCSTPIE; //Enable STOP condition interrupt
|
42 |
|
43 | _BIS_SR(GIE); // Enable Interrupts
|
44 | }
|
45 |
|
46 | void i2c_send_adr (unsigned int address) // only Start, Adress, Stop -> for HYT271 Sensor
|
47 | {
|
48 | UCB0I2CSA = address; // Set slaveaddress
|
49 | UCB0CTLW0 |= UCTR; // Set MSP430 in transmit state
|
50 | UCB0CTLW0 |= UCTXSTT; // Startcondition followed by a stopcondition sends only start|slave-adr|stop
|
51 | UCB0CTLW0 |= UCTXSTP; // Stopcondition
|
52 | }
|
53 |
|
54 | unsigned char i2c_read_byte(unsigned char adr, unsigned char bytes_expected) // received bytes are stroed in RXData
|
55 | {
|
56 | RXData[0] = 0x0;
|
57 | RXData[1] = 0x0;
|
58 | RXData[2] = 0x0;
|
59 | RXData[3] = 0x0;
|
60 | //clear_rx_buffer(); // warum hat diese Zeile laut compiler keine Auswirkungen auf den code?? Ich habe sie testweise auskommentiert und das Array manuell gelöscht
|
61 | UCB0TBCNT = bytes_expected; //number of bytes to be received
|
62 | UCB0I2CSA = adr; // Set slaveaddress
|
63 | UCB0CTLW0 &= ~UCTR; // Set MSP430 in receive state
|
64 | UCB0CTLW0 |= UCTXSTT; // Set Start Bit
|
65 | RXByteCtr = bytes_expected-1;
|
66 | //UCB0CTLW1 |= UCASTP_2; //automatic stop generated
|
67 | //after UCB0TBCNT is reached
|
68 | return 0;
|
69 | }
|
70 |
|
71 |
|
72 | #pragma vector = USCI_B0_VECTOR
|
73 | __interrupt void USCIB0_ISR(void)
|
74 | {
|
75 | switch(__even_in_range(UCB0IV,0x1E))
|
76 | {
|
77 | case 0x00: break; // Vector 0: No interrupts break;
|
78 | case 0x02: break;
|
79 | case 0x04:
|
80 | UCB0CTLW0 |= UCTXSTT; // resend start if NACK
|
81 | break; // Vector 4: NACKIFG break;
|
82 | case 0x08: // clear Flag when Stopcondition was detected
|
83 | UCB0IFG &=~ UCSTPIFG;
|
84 | break;
|
85 | case 0x16:
|
86 | __delay_cycles(30);
|
87 | RXData[RXByteCtr] = UCB0RXBUF; // Get RX data
|
88 | UCB0RXBUF= 0x00; // auch nur zu Testzwecken. Das Reg. wir normalerweise beim Empfang neuer Daten überschrieben
|
89 | if (RXByteCtr > 0)
|
90 | {
|
91 | RXByteCtr--;
|
92 | break;
|
93 | }
|
94 | else
|
95 | {
|
96 | break;
|
97 | }
|
98 | case 0x18:
|
99 | /*if (TXByteCtr) // Check TX byte counter
|
100 | {
|
101 | UCB0TXBUF = sendBytes[TXByteCtr-1]; // Load TX buffer
|
102 | TXByteCtr--; // Decrement TX byte counter
|
103 | if (TXByteCtr == 0)
|
104 | {
|
105 | __delay_cycles(30);
|
106 | UCB0CTLW0 |= UCTXSTP; // I2C stop condition
|
107 | }
|
108 | }
|
109 | else
|
110 | {
|
111 | UCB0IFG &= ~UCTXIFG; // Clear USCI_B0 TX int flag
|
112 | }*/
|
113 | break; // Vector 26: TXIFG0 break;
|
114 | case 0x1A:
|
115 | UCB0IFG &= ~UCBCNTIFG;
|
116 | break;
|
117 | default: break;
|
118 | }
|
119 | }
|
Thread beobachten
Seitenaufteilung abschalten