/** * Copyright (c) 2020 Raspberry Pi (Trading) Ltd. * * SPDX-License-Identifier: BSD-3-Clause */ #include <stdio.h> #include <string.h> #include "pico/stdlib.h" #include "pico/binary_info.h" #include "hardware/i2c.h" #include "string.h" /* Example code to talk to a PA1010D Mini GPS module. This example reads the Recommended Minimum Specific GNSS Sentence, which includes basic location and time data, each second, formats and displays it. Connections on Raspberry Pi Pico board, other boards may vary. GPIO PICO_DEFAULT_I2C_SDA_PIN (On Pico this is 4 (physical pin 6)) -> SDA on PA1010D board GPIO PICO_DEFAULT_I2C_SCK_PIN (On Pico this is 5 (physical pin 7)) -> SCL on PA1010D board 3.3v (physical pin 36) -> VCC on PA1010D board GND (physical pin 38) -> GND on PA1010D board */ const int addr = 0x10; #define MAX_READ 250 #ifdef i2c_default void pa1010d_write_command(const char command[], int com_length) { // Convert character array to bytes for writing uint8_t int_command[com_length]; for (int i = 0; i < com_length; ++i) { int_command[i] = command[i]; i2c_write_blocking(i2c_default, addr, &int_command[i], 1, true); } } void pa1010d_parse_string(char output[], char protocol[]) { // Finds location of protocol message in output char *com_index = strstr(output, protocol); int p = com_index - output; // Splits components of output sentence into array #define NO_OF_FIELDS 14 #define MAX_LEN 15 int n = 0; int m = 0; char gps_data[NO_OF_FIELDS][MAX_LEN]; memset(gps_data, 0, sizeof(gps_data)); bool complete = false; while (output[p] != '$' && n < MAX_LEN && complete == false) { if (output[p] == ',' || output[p] == '*') { n += 1; m = 0; } else { gps_data[n][m] = output[p]; // Checks if sentence is complete if (m < NO_OF_FIELDS) { m++; } else { complete = true; } } p++; } // Displays GNRMC data // Similarly, additional if statements can be used to add more protocols if (strcmp(protocol, "GNRMC") == 0) { printf("Protocol:%s\n", gps_data[0]); printf("UTC Time: %s\n", gps_data[1]); printf("Status: %s\n", gps_data[2][0] == 'V' ? "Data invalid. GPS fix not found." : "Data Valid"); printf("Latitude: %s\n", gps_data[3]); printf("N/S indicator: %s\n", gps_data[4]); printf("Longitude: %s\n", gps_data[5]); printf("E/W indicator: %s\n", gps_data[6]); printf("Speed over ground: %s\n", gps_data[7]); printf("Course over ground: %s\n", gps_data[8]); printf("Date: %c%c/%c%c/%c%c\n", gps_data[9][0], gps_data[9][1], gps_data[9][2], gps_data[9][3], gps_data[9][4], gps_data[9][5]); printf("Magnetic Variation: %s\n", gps_data[10]); printf("E/W degree indicator: %s\n", gps_data[11]); printf("Mode: %s\n", gps_data[12]); printf("Checksum: %c%c\n", gps_data[13][0], gps_data[13][1]); } } void pa1010d_read_raw(char numcommand[]) { uint8_t buffer[MAX_READ]; int i = 0; bool complete = false; i2c_read_blocking(i2c_default, addr, buffer, MAX_READ, false); // Convert bytes to characters while (i < MAX_READ && complete == false) { numcommand[i] = buffer[i]; // Stop converting at end of message if (buffer[i] == 10 && buffer[i + 1] == 10) { complete = true; } i++; } } #endif int main() { stdio_init_all(); #if !defined(i2c_default) || !defined(PICO_DEFAULT_I2C_SDA_PIN) || !defined(PICO_DEFAULT_I2C_SCL_PIN) #warning i2c/mpu6050_i2c example requires a board with I2C pins puts("Default I2C pins were not defined"); #else char numcommand[MAX_READ]; // Decide which protocols you would like to retrieve data from char init_command[] = "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n"; // This example will use I2C0 on the default SDA and SCL pins (4, 5 on a Pico) i2c_init(i2c_default, 400 * 1000); gpio_set_function(PICO_DEFAULT_I2C_SDA_PIN, GPIO_FUNC_I2C); gpio_set_function(PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C); gpio_pull_up(PICO_DEFAULT_I2C_SDA_PIN); gpio_pull_up(PICO_DEFAULT_I2C_SCL_PIN); // Make the I2C pins available to picotool bi_decl(bi_2pins_with_func(PICO_DEFAULT_I2C_SDA_PIN, PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C)); printf("Hello, PA1010D! Reading raw data from module...\n"); pa1010d_write_command(init_command, sizeof(init_command)); while (1) { // Clear array memset(numcommand, 0, MAX_READ); // Read and re-format pa1010d_read_raw(numcommand); pa1010d_parse_string(numcommand, "GNRMC"); // Wait for data to refresh sleep_ms(1000); // Clear terminal printf("\033[1;1H\033[2J"); } #endif }

This firmware image was imported from the pico-examples repository. 


Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
   disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
   disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.