Rev Author Line No. Line
3470 kakl 1 // Atomic counter with I2C and RS232 output
2  
3 // Usage conditions:
4 // 1. The first I2C or RS232 readout can be performed minimally 20 s after power up.
5 // 2. The I2C internal address 0 has to be read first.
6 // 3. An I2C readout can be performed at 15-th, 35-th and 55-th second of UTC.
7 //
8 // Counter gives 32 bit value:
9 // I2C register address 0 = LSB
10 // I2C register address 3 = MSB
11  
3463 kaklik 12 #define ID "$Id: main.c 2916 2013-04-14 17:42:03Z kaklik $"
3458 kaklik 13 #include "main.h"
3463 kaklik 14 #use i2c(SLAVE, Fast, sda=PIN_C4, scl=PIN_C3, force_hw, address=0xA2)
3458 kaklik 15  
3470 kakl 16 #include <string.h>
3458 kaklik 17  
3462 kaklik 18 #define SEL0 PIN_E0 // external counter division ratio
19 #define SEL1 PIN_E1 // external counter division ratio
20 #define MR PIN_E2 // external counter master reset
21 #define CLKI PIN_C0 // internal counter input
3458 kaklik 22  
3470 kakl 23 unsigned int32 count; // count per second
3458 kaklik 24  
3470 kakl 25 #define BUF_LEN 4
26 int8 buffer[BUF_LEN]; // I2C buffer
3463 kaklik 27 int8 address=0;
3462 kaklik 28  
29 unsigned int16 of=0; // count of overflow
30  
3470 kakl 31 // 1x 100 us per 10 s UTC synchronised
32 const char cmd[40]={0xB5, 0x62, 0x06, 0x31, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00, 0x80, 0x96, 0x98, 0x00, 0xE0, 0xC8, 0x10, 0x00, 0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x73, 0x00, 0x00, 0x00, 0xC6, 0x51};
33  
3458 kaklik 34 #INT_SSP
35 void ssp_interupt ()
36 {
3470 kakl 37 int8 incoming, state;
3458 kaklik 38  
39 state = i2c_isr_state();
3470 kakl 40  
41 if(state < 0x80) //Master is sending data
42 {
43 incoming = i2c_read(); // Read byte
44  
45 if(state == 1) //Second received byte is address of register
3458 kaklik 46 {
3470 kakl 47 address = incoming;
3458 kaklik 48 }
49 }
50 if(state == 0x80) //Master is requesting data
51 {
3470 kakl 52 //i2c_read(); // Dummy read of I2C device address
53  
54 if(address == 0) // Change buffer atomically at reading of the first byte
55 {
56 buffer[0]=make8(count,0);
57 buffer[1]=make8(count,1);
58 buffer[2]=make8(count,2);
59 buffer[3]=make8(count,3);
60 }
61 if(address <= BUF_LEN) i2c_write(buffer[address]); // Prepare one byte to SSP buffer
62 else
63 {
64 i2c_write(0x00); // There is nothing to prepare, so zero
65 }
3458 kaklik 66 }
3470 kakl 67  
68 if(state == 0x81) //Master is requesting data
69 {
70 i2c_write(buffer[1]); // Prepare next byte to SSP buffer
71 }
72 if(state == 0x82) //Master is requesting data
73 {
74 i2c_write(buffer[2]); // Prepare next byte to SSP buffer
75 }
76 if(state == 0x83) //Master is requesting data
77 {
78 i2c_write(buffer[3]); // Prepare next byte to SSP buffer
79 }
80  
81 if(state > 0x83) //Master is requesting data
82 {
83 i2c_write(0x00); // There is nothing to prepare, so zero
84 }
3458 kaklik 85 }
86  
87  
3463 kaklik 88  
3470 kakl 89 #int_EXT // Interrupt from 1PPS (RB0)
3462 kaklik 90 void EXT_isr(void)
91 {
92 unsigned int16 countH;
93 unsigned int8 countL;
3470 kakl 94 int16 of2;
3462 kaklik 95  
3470 kakl 96 of2=of; // read overflow counter
97 countH=get_timer1(); // read internal counter
3462 kaklik 98 countL=0;
99 output_low(SEL0);
100 output_low(SEL1);
101 countL=input(CLKI); // read bit 0 of external counter
102 output_high(SEL0);
3470 kakl 103 // output_low(SEL1);
3462 kaklik 104 countL|=input(CLKI)<<1; // read bit 1 of external counter
105 output_low(SEL0);
106 output_high(SEL1);
107 countL|=input(CLKI)<<2; // read bit 2 of external counter
108 output_high(SEL0);
3470 kakl 109 // output_high(SEL1);
3462 kaklik 110 countL|=input(CLKI)<<3; // read bit 3 of external counter
111  
112 output_low(MR); // External counter Master Reset
113 output_high(MR);
114 set_timer1(0); // Internal counter reset
3470 kakl 115 of=0; // Overflow counter reset
3462 kaklik 116  
3470 kakl 117 count=((unsigned int32)of2<<20)+((unsigned int32)countH<<4)+(unsigned int32)countL; // concatenate
3462 kaklik 118  
3470 kakl 119 printf("%010Lu\r\n", count);
3462 kaklik 120 }
121  
122 #int_TIMER1 // Interrupf from overflow
123 void TIMER1_isr(void)
124 {
125 of++;
126 }
127  
128  
3458 kaklik 129 void main()
130 {
3470 kakl 131 setup_adc_ports(NO_ANALOGS|VSS_VDD);
3458 kaklik 132 setup_adc(ADC_OFF);
3470 kakl 133 // setup_spi(SPI_SS_DISABLED); //must not be set if I2C are in use!
3458 kaklik 134 setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
3470 kakl 135 setup_wdt(WDT_2304MS);
3458 kaklik 136 setup_timer_1(T1_EXTERNAL|T1_DIV_BY_1);
3470 kakl 137 setup_timer_2(T2_DISABLED,0,1);
3458 kaklik 138 setup_comparator(NC_NC_NC_NC);
139 setup_vref(FALSE);
3463 kaklik 140  
3470 kakl 141 restart_wdt();
142 delay_ms(1000);
143 restart_wdt();
144  
145 // setup GPS
146 {
147 int n;
148 for (n=0;n<40;n++) putc(cmd[n]);
149 }
3463 kaklik 150  
3470 kakl 151 ext_int_edge( L_TO_H ); // set 1PPS active edge
152 enable_interrupts(INT_TIMER1);
153 enable_interrupts(INT_EXT);
3463 kaklik 154 enable_interrupts(INT_SSP);
155 enable_interrupts(GLOBAL);
3458 kaklik 156  
3470 kakl 157 buffer[0]=0x0; // Clear I2C output buffer
158 buffer[1]=0x0;
159 buffer[2]=0x0;
160 buffer[3]=0x0;
3458 kaklik 161  
3470 kakl 162 printf("\r\ncvak...\r\n");
3463 kaklik 163  
3458 kaklik 164 while(true)
3462 kaklik 165 {
3470 kakl 166 restart_wdt();
167 delay_ms(1000);
168 // printf("%X %X %X %X\r\n", buffer[0],buffer[1],buffer[2],buffer[3]);
3458 kaklik 169 }
170 }