Work in progress: Receiving NMEA sentences, Measure period of PPS. Debugging.

CMakeLists.txt

@@ -33,6 +33,7 @@ pico_generate_pio_header(pico-hf-oscillator-test ${CMAKE_CURRENT_LIST_DIR}/piodc
 
 target_sources(pico-hf-oscillator-test PUBLIC
 	      ${CMAKE_CURRENT_LIST_DIR}/lib/assert.c
+#        ${CMAKE_CURRENT_LIST_DIR}/lib/utility.c
         ${CMAKE_CURRENT_LIST_DIR}/piodco/piodco.c
         ${CMAKE_CURRENT_LIST_DIR}/gpstime/GPStime.c
         ${CMAKE_CURRENT_LIST_DIR}/test.c
@@ -42,11 +43,12 @@ pico_set_program_name(pico-hf-oscillator-test "pico-hf-oscillator-test")
 pico_set_program_version(pico-hf-oscillator-test "0.9")
 
 pico_enable_stdio_uart(pico-hf-oscillator-test 1)
-pico_enable_stdio_usb(pico-hf-oscillator-test 0)
+pico_enable_stdio_usb(pico-hf-oscillator-test 1)
 
 # Add the standard include files to the build
 target_include_directories(pico-hf-oscillator-test PRIVATE
   ${CMAKE_CURRENT_LIST_DIR}
+  ${CMAKE_CURRENT_LIST_DIR}/gpstime
   ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
 )
 

gpstime/GPStime.c

@@ -64,11 +64,13 @@
 ///////////////////////////////////////////////////////////////////////////////
 #include "GPStime.h"
 
-GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_pio)
+static GPStimeData *spGPStimeData = NULL;
+
+GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_gpio)
 {
     ASSERT_(0 == uart_id || 1 == uart_id);
     ASSERT_(uart_baud <= 115200);
-    ASSERT_(pps_pio < 29);
+    ASSERT_(pps_gpio < 29);
 
     // Set up our UART with the required speed.
     uart_init(uart_id ? uart1 : uart0, uart_baud);
@@ -82,7 +84,13 @@ GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_pio)
     ASSERT_(pgt);
     pgt->_uart_id = uart_id;
     pgt->_uart_baudrate = uart_baud;
-    pgt->_pps_pio = pps_pio;
+    pgt->_pps_pio = pps_gpio;
+
+    spGPStimeData = &pgt->_time_data;
+
+    gpio_init(pps_gpio);
+    gpio_set_dir(pps_gpio, GPIO_IN);
+    gpio_set_irq_enabled_with_callback(pps_gpio, GPIO_IRQ_EDGE_RISE, true, &GPStimePPScallback);
 }
 
 void GPStimeDestroy(GPStimeContext **pp)
@@ -94,3 +102,36 @@ void GPStimeDestroy(GPStimeContext **pp)
     free(*pp);
     *pp = NULL;
 }
+
+void __not_in_flash_func (GPStimePPScallback)(uint gpio, uint32_t events)
+{   
+    if(spGPStimeData)
+    {
+        const uint64_t tm64 = GetUptime64();
+        spGPStimeData->_u64_sysclk_pps_last = tm64;
+        const int32_t ksliding_len = sizeof(spGPStimeData->_pu64_sliding_pps_tm) 
+                                   / sizeof(spGPStimeData->_pu64_sliding_pps_tm[0]);
+        
+        ++spGPStimeData->_ix_last;
+        spGPStimeData->_ix_last %= ksliding_len;
+        const uint8_t ix_oldest = spGPStimeData->_ix_last;
+
+        int64_t dt_1M = 1000000LL * (tm64 - spGPStimeData->_pu64_sliding_pps_tm[ix_oldest]);
+        spGPStimeData->_pu64_sliding_pps_tm[spGPStimeData->_ix_last] = tm64;
+
+        if(spGPStimeData->_u64_pps_period_1M)
+        {
+            spGPStimeData->_u64_pps_period_1M += iSAR(dt_1M - spGPStimeData->_u64_pps_period_1M + 4, 3);
+        }
+        else
+        {
+            spGPStimeData->_u64_pps_period_1M = dt_1M;
+        }
+#if 1
+    dt_1M = (dt_1M + ksliding_len/2) / ksliding_len;
+    const uint64_t tmp = (spGPStimeData->_u64_pps_period_1M + ksliding_len/2) / ksliding_len;
+    printf("%llu %lld %llu\n", spGPStimeData->_u64_sysclk_pps_last, dt_1M, tmp);
+#endif
+
+    }
+}

gpstime/GPStime.h

@@ -70,16 +70,26 @@
 #include <stdlib.h>
 #include "pico/stdlib.h"
 #include "hardware/uart.h"
+#include "../defines.h"
 #include "../lib/assert.h"
+#include "../lib/utility.h"
 
 #define ASSERT_(x) assert_(x)
 
 typedef struct
 {
-    uint32_t _tm_unix_last;
-    float _flt_lat_deg, _flt_lon_deg;
+    uint8_t _u8_is_sol_active;              // A navigation solution is valid.
+    uint32_t _u32_utime_nmea_last;          // The last unix time received from GPS.
+    uint64_t _u64_sysclk_nmea_last;         // The sysclk of the last unix time received.
+    int64_t _i64_lat_100k, _i64_lon_100k;   // The lat, lon, degrees, multiplied by 1e5.
 
-    float _flt_GDOP, _flt_TDOP;
+    uint64_t _u64_sysclk_pps_last;          // The sysclk of the last rising edge of PPS.
+    uint64_t _u64_pps_period_1M;            // The PPS avg. period *1e6, filtered.
+
+    uint64_t _pu64_sliding_pps_tm[32];      // A sliding window to store PPS periods.
+    uint8_t _ix_last;                       // An index of last write to sliding window.
+
+    int32_t _i32_LO_freq_corr_milhz;        // SYSCLK frequency correction, milliHertz.
 
 } GPStimeData;
 
@@ -92,13 +102,17 @@ typedef struct
     GPStimeData _time_data;
 
     uint8_t _pbytebuff[256];
+    uint8_t _u8_ixw;
     uint8_t _is_sentence_ready;
 
 } GPStimeContext;
 
-GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_pio);
+GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_gpio);
 void GPStimeDestroy(GPStimeContext **pp);
 
-void GPStimeTick(GPStimeContext *pg);
+void GPStimeISRTick(GPStimeContext *pg);
+int GPStimeProcNMEAsentence(GPStimeContext *pg);
+
+void __not_in_flash_func (GPStimePPScallback)(uint gpio, uint32_t events);
 
 #endif

lib/utility.h

@@ -0,0 +1,20 @@
+#ifndef UTILITY_H_
+#define UTILITY_H_
+
+#include <stdint.h>
+#include "pico/stdlib.h"
+
+inline uint64_t GetUptime64(void)
+{
+    const uint32_t lo = timer_hw->timelr;
+    const uint32_t hi = timer_hw->timehr;
+
+    return ((uint64_t)hi << 32U) | lo;
+}
+
+inline uint32_t GetTime32(void)
+{
+    return timer_hw->timelr;
+}
+
+#endif

test.c

@@ -68,6 +68,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 #include <string.h>
 #include <stdlib.h>
+#include <stdio.h>
 
 #include "defines.h"
 
@@ -75,10 +76,13 @@
 #include "build/dco.pio.h"
 #include "hardware/vreg.h"
 #include "pico/multicore.h"
+#include "pico/stdio/driver.h"
 
 #include "./lib/assert.h"
 #include "hwdefs.h"
 
+#include <GPStime.h>
+
 #define GEN_FRQ_HZ 9400000L
 
 PioDco DCO;
@@ -211,6 +215,26 @@ int main()
     const uint32_t clkhz = PLL_SYS_MHZ * 1000000L;
     set_sys_clock_khz(clkhz / 1000L, true);
 
+    stdio_init_all();
+
+    //uart_init(uart0, 9600);
+    //gpio_set_function(0, GPIO_FUNC_UART);
+    //gpio_set_function(1, GPIO_FUNC_UART);
+
+    GPStimeContext *pGPS = GPStimeInit(0, 9600, 2);
+    for(;;) {}
+
+    for(;;) 
+    {
+        char ch = uart_getc(uart0);
+        if(ch)
+        {
+            stdio_set_driver_enabled(&stdio_uart, false);
+            printf("%c", ch);
+            stdio_set_driver_enabled(&stdio_uart, true);
+        }
+    }
+
     gpio_init(PICO_DEFAULT_LED_PIN);
     gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);