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  
3735 kakl 25 int1 fire_setup; // flag for sending setup to GPS
26  
3470 kakl 27 #define BUF_LEN 4
28 int8 buffer[BUF_LEN]; // I2C buffer
3463 kaklik 29 int8 address=0;
3462 kaklik 30  
31 unsigned int16 of=0; // count of overflow
3735 kakl 32  
33 // 1x 100 us per 10 s UTC synchronised; 40 configuration bytes
34 char cmd[50]={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};
35  
3734 kakl 36 // configure GPS
37 void setup_GPS()
38 {
39 int n;
3735 kakl 40 int len;
41 len=cmd[0];
42 for (n=1;n<=len;n++) putc(cmd[n]);
3734 kakl 43 }
3462 kaklik 44  
3458 kaklik 45 #INT_SSP
46 void ssp_interupt ()
47 {
3470 kakl 48 int8 incoming, state;
3458 kaklik 49  
50 state = i2c_isr_state();
3470 kakl 51  
52 if(state < 0x80) //Master is sending data
53 {
54 incoming = i2c_read(); // Read byte
55  
56 if(state == 1) //Second received byte is address of register
3458 kaklik 57 {
3470 kakl 58 address = incoming;
3458 kaklik 59 }
3735 kakl 60  
61 if(state == 2) //Thid received byte are configuration data
62 {
63 if ((address==0)&&(incoming==0))
64 {
65 fire_setup = 1; // Write configuration to the GPS if configuration data length is 0
66 }
67 else
68 {
69 cmd[address] = incoming; // Store byte to configuration sentence
70 }
71 }
3458 kaklik 72 }
73 if(state == 0x80) //Master is requesting data
74 {
3470 kakl 75 //i2c_read(); // Dummy read of I2C device address
76  
77 if(address == 0) // Change buffer atomically at reading of the first byte
78 {
79 buffer[0]=make8(count,0);
80 buffer[1]=make8(count,1);
81 buffer[2]=make8(count,2);
82 buffer[3]=make8(count,3);
83 }
3735 kakl 84 if(address <= BUF_LEN)
3470 kakl 85 {
3735 kakl 86 i2c_write(buffer[address]); // Prepare one byte to SSP buffer
87 }
88 else
89 {
3470 kakl 90 i2c_write(0x00); // There is nothing to prepare, so zero
91 }
3458 kaklik 92 }
3470 kakl 93  
94 if(state == 0x81) //Master is requesting data
95 {
96 i2c_write(buffer[1]); // Prepare next byte to SSP buffer
97 }
98 if(state == 0x82) //Master is requesting data
99 {
100 i2c_write(buffer[2]); // Prepare next byte to SSP buffer
101 }
102 if(state == 0x83) //Master is requesting data
103 {
3735 kakl 104 i2c_write(buffer[3]); // Prepare next byte to SSP buffer
3470 kakl 105 }
106  
107 if(state > 0x83) //Master is requesting data
108 {
109 i2c_write(0x00); // There is nothing to prepare, so zero
110 }
3458 kaklik 111 }
112  
113  
3463 kaklik 114  
3470 kakl 115 #int_EXT // Interrupt from 1PPS (RB0)
3462 kaklik 116 void EXT_isr(void)
117 {
118 unsigned int16 countH;
119 unsigned int8 countL;
3470 kakl 120 int16 of2;
3462 kaklik 121  
3470 kakl 122 of2=of; // read overflow counter
123 countH=get_timer1(); // read internal counter
3462 kaklik 124 countL=0;
125 output_low(SEL0);
126 output_low(SEL1);
127 countL=input(CLKI); // read bit 0 of external counter
128 output_high(SEL0);
3470 kakl 129 // output_low(SEL1);
3462 kaklik 130 countL|=input(CLKI)<<1; // read bit 1 of external counter
131 output_low(SEL0);
132 output_high(SEL1);
133 countL|=input(CLKI)<<2; // read bit 2 of external counter
134 output_high(SEL0);
3470 kakl 135 // output_high(SEL1);
3462 kaklik 136 countL|=input(CLKI)<<3; // read bit 3 of external counter
137  
138 output_low(MR); // External counter Master Reset
139 output_high(MR);
140 set_timer1(0); // Internal counter reset
3470 kakl 141 of=0; // Overflow counter reset
3462 kaklik 142  
3470 kakl 143 count=((unsigned int32)of2<<20)+((unsigned int32)countH<<4)+(unsigned int32)countL; // concatenate
3462 kaklik 144  
3501 kakl 145 // printf("%010Lu\r\n", count);
3462 kaklik 146 }
147  
148 #int_TIMER1 // Interrupf from overflow
149 void TIMER1_isr(void)
150 {
151 of++;
152 }
153  
3458 kaklik 154 void main()
155 {
3470 kakl 156 setup_adc_ports(NO_ANALOGS|VSS_VDD);
3458 kaklik 157 setup_adc(ADC_OFF);
3470 kakl 158 // setup_spi(SPI_SS_DISABLED); //must not be set if I2C are in use!
3458 kaklik 159 setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
3470 kakl 160 setup_wdt(WDT_2304MS);
3458 kaklik 161 setup_timer_1(T1_EXTERNAL|T1_DIV_BY_1);
3470 kakl 162 setup_timer_2(T2_DISABLED,0,1);
3458 kaklik 163 setup_comparator(NC_NC_NC_NC);
164 setup_vref(FALSE);
3463 kaklik 165  
3470 kakl 166 restart_wdt();
167 delay_ms(1000);
168 restart_wdt();
169  
170 // setup GPS
3734 kakl 171 setup_GPS();
3463 kaklik 172  
3470 kakl 173 ext_int_edge( L_TO_H ); // set 1PPS active edge
174 enable_interrupts(INT_TIMER1);
175 enable_interrupts(INT_EXT);
3463 kaklik 176 enable_interrupts(INT_SSP);
177 enable_interrupts(GLOBAL);
3458 kaklik 178  
3470 kakl 179 buffer[0]=0x0; // Clear I2C output buffer
180 buffer[1]=0x0;
181 buffer[2]=0x0;
182 buffer[3]=0x0;
3458 kaklik 183  
3735 kakl 184 //printf("\r\ncvak...\r\n");
185  
186 fire_setup = 0;
3463 kaklik 187  
3458 kaklik 188 while(true)
3462 kaklik 189 {
3470 kakl 190 restart_wdt();
3735 kakl 191 delay_ms(1000);
192 if (fire_setup)
193 {
194 setup_GPS(); // Write configuration to the GPS
195 fire_setup = 0;
196 }
197 //printf("%X %X %X %X\r\n", buffer[0],buffer[1],buffer[2],buffer[3]);
198 //printf("%010Lu\r\n", count);
3458 kaklik 199 }
200 }