+GPStime sketch and proto-structs.

CMakeLists.txt

@@ -34,6 +34,7 @@ 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}/piodco/piodco.c
+        ${CMAKE_CURRENT_LIST_DIR}/gpstime/GPStime.c
         ${CMAKE_CURRENT_LIST_DIR}/test.c
         )
 

gpstime/GPStime.c

@@ -0,0 +1,96 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+//  Roman Piksaykin [piksaykin@gmail.com], R2BDY, PhD
+//  https://www.qrz.com/db/r2bdy
+//
+///////////////////////////////////////////////////////////////////////////////
+//
+//
+//  gpstime.h - GPS time reference utilities for digital controlled radio freq
+//              oscillator based on Raspberry Pi Pico.
+//
+//  DESCRIPTION
+//
+//      GPS time utilities for PioDco oscillator provides a precise reference
+//  frequency in order to obtain an absolute accuracy of PioDco. The value of
+//  this  accuracy  depends  on quality of navigation solution of GPS receiver.
+//  This quality can be estimated by GDOP (geometric dilution of precision) and
+//  TDOP (time dilution of precision) received in NMEA-0183 message packet from
+//  GPS receiver.
+//      The Pico's frequency error due to drift of its CLK oscillator is
+//  calculated by that utilities and is used to shift PioDco frequency to
+//  compensate the drift. So, the absolute frequency value which we possess
+//  on the GPIO pin is supposed to be much more accurate when using GPS time
+//  utilities.
+//      Owing to the meager PioDco frequency step in millihertz range, we obtain
+//  a quasi-analog precision frequency source.
+//      This is an experimental project of amateur radio class and it is devised
+//  by me on the free will base in order to experiment with QRP narrowband
+//  digital modes including extremely ones such as QRSS.
+//      I gracefully appreciate any thoughts or comments on that matter.
+//
+//  PLATFORM
+//      Raspberry Pi pico.
+//
+//  REVISION HISTORY
+// 
+//      Rev 0.1   25 Nov 2023   Initial release
+//
+//  PROJECT PAGE
+//      https://github.com/RPiks/pico-hf-oscillator
+//
+//  LICENCE
+//      MIT License (http://www.opensource.org/licenses/mit-license.php)
+//
+//  Copyright (c) 2023 by Roman Piksaykin
+//  
+//  Permission is hereby granted, free of charge,to any person obtaining a copy
+//  of this software and associated documentation files (the Software), to deal
+//  in the Software without restriction,including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY,WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+///////////////////////////////////////////////////////////////////////////////
+#include "GPStime.h"
+
+GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_pio)
+{
+    ASSERT_(0 == uart_id || 1 == uart_id);
+    ASSERT_(uart_baud <= 115200);
+    ASSERT_(pps_pio < 29);
+
+    // Set up our UART with the required speed.
+    uart_init(uart_id ? uart1 : uart0, uart_baud);
+
+    // Set the TX and RX pins by using the function select on the GPIO
+    // Set datasheet for more information on function select
+    gpio_set_function(uart_id ? 8 : 12, GPIO_FUNC_UART);
+    gpio_set_function(uart_id ? 9 : 13, GPIO_FUNC_UART);
+
+    GPStimeContext *pgt = calloc(1, sizeof(GPStimeContext));
+    ASSERT_(pgt);
+    pgt->_uart_id = uart_id;
+    pgt->_uart_baudrate = uart_baud;
+    pgt->_pps_pio = pps_pio;
+}
+
+void GPStimeDestroy(GPStimeContext **pp)
+{
+    ASSERT_(pp);
+    ASSERT_(*pp);
+
+    uart_deinit((*pp)->_uart_id ? uart1 : uart0);
+    free(*pp);
+    *pp = NULL;
+}

gpstime/GPStime.h

@@ -0,0 +1,104 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+//  Roman Piksaykin [piksaykin@gmail.com], R2BDY, PhD
+//  https://www.qrz.com/db/r2bdy
+//
+///////////////////////////////////////////////////////////////////////////////
+//
+//
+//  gpstime.h - GPS time reference utilities for digital controlled radio freq
+//              oscillator based on Raspberry Pi Pico.
+//
+//  DESCRIPTION
+//
+//      GPS time utilities for PioDco oscillator provides a precise reference
+//  frequency in order to obtain an absolute accuracy of PioDco. The value of
+//  this  accuracy  depends  on quality of navigation solution of GPS receiver.
+//  This quality can be estimated by GDOP (geometric dilution of precision) and
+//  TDOP (time dilution of precision) received in NMEA-0183 message packet from
+//  GPS receiver.
+//      The Pico's frequency error due to drift of its CLK oscillator is
+//  calculated by that utilities and is used to shift PioDco frequency to
+//  compensate the drift. So, the absolute frequency value which we possess
+//  on the GPIO pin is supposed to be much more accurate when using GPS time
+//  utilities.
+//      Owing to the meager PioDco frequency step in millihertz range, we obtain
+//  a quasi-analog precision frequency source.
+//      This is an experimental project of amateur radio class and it is devised
+//  by me on the free will base in order to experiment with QRP narrowband
+//  digital modes including extremely ones such as QRSS.
+//      I gracefully appreciate any thoughts or comments on that matter.
+//
+//  PLATFORM
+//      Raspberry Pi pico.
+//
+//  REVISION HISTORY
+// 
+//      Rev 0.1   25 Nov 2023   Initial release
+//
+//  PROJECT PAGE
+//      https://github.com/RPiks/pico-hf-oscillator
+//
+//  LICENCE
+//      MIT License (http://www.opensource.org/licenses/mit-license.php)
+//
+//  Copyright (c) 2023 by Roman Piksaykin
+//  
+//  Permission is hereby granted, free of charge,to any person obtaining a copy
+//  of this software and associated documentation files (the Software), to deal
+//  in the Software without restriction,including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY,WHETHER IN AN ACTION OF CONTRACT,TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+///////////////////////////////////////////////////////////////////////////////
+#ifndef GPSTIME_H_
+#define GPSTIME_H_
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "pico/stdlib.h"
+#include "hardware/uart.h"
+#include "../lib/assert.h"
+
+#define ASSERT_(x) assert_(x)
+
+typedef struct
+{
+    uint32_t _tm_unix_last;
+    float _flt_lat_deg, _flt_lon_deg;
+
+    float _flt_GDOP, _flt_TDOP;
+
+} GPStimeData;
+
+typedef struct
+{
+    int _uart_id;
+    int _uart_baudrate;
+    int _pps_pio;
+
+    GPStimeData _time_data;
+
+    uint8_t _pbytebuff[256];
+    uint8_t _is_sentence_ready;
+
+} GPStimeContext;
+
+GPStimeContext *GPStimeInit(int uart_id, int uart_baud, int pps_pio);
+void GPStimeDestroy(GPStimeContext **pp);
+
+void GPStimeTick(GPStimeContext *pg);
+
+#endif