lf-atgm336h

Reusable ATGM336H GPS+BDS Dual-Mode GNSS receiver driver library for the Raspberry Pi Pico / Pico 2 C SDK, packaged as a Conan package.

This is part of the Lost + Found suite of projects.

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🛠️ Usage with CMake

Copy the driver directory into your project as a subdirectory:

add_subdirectory(lib/lf-atgm336h)

target_link_libraries(your_project PRIVATE
    lf-atgm336h
)

And in your C/C++ code:

#include "lf_atgm336h.h"

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🔌 Hardware Setup

Connect the ATGM336H GPS+BDS module to your Raspberry Pi Pico/Pico 2:

• Pico GP0 (TX) <-> Breakout RXD
• Pico GP1 (RX) <-> Breakout TXD
• Pico GP2 <-> Breakout PPS (Pulse Per Second timing pin)
• Pico GND <-> Breakout GND
• Pico 3V3 OUT <-> Breakout VCC

(Note: Pins and UART hardware instance can be configured during context initialization).

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💡 Example

#include <stdio.h>
#include "pico/stdlib.h"
#include "lf_atgm336h.h"

int main() {
    stdio_init_all();
    sleep_ms(2000);

    lf_atgm336h_t gps;
    
    // Initialize the module on UART0, GP0 (TX), GP1 (RX), and GP2 (PPS)
    if (!lf_atgm336h_init(&gps, uart0, 9600, 0, 1, 2)) {
        printf("Failed to initialize ATGM336H driver!\n");
        return -1;
    }

    printf("ATGM336H Driver Initialized successfully.\n");

    // Configure the module update frequency to 5Hz and disable GSV sentences using CASIC command
    // (Note: lf_atgm336h_send_command automatically calculates and appends NMEA XOR checksums)
    lf_atgm336h_send_command(&gps, "PCAS02,200"); // 200ms interval = 5Hz
    lf_atgm336h_send_command(&gps, "PCAS03,0,0,0,0,0,0,0,0,0"); // Disable verbose GSV/GSA sentences

    while (true) {
        // Asynchronously check for PPS pulses
        uint64_t last_pulse;
        uint32_t count;
        if (lf_atgm336h_get_pps(&gps, &last_pulse, &count)) {
            printf("[PPS] Pulse #%u triggered at %llu us\n", count, last_pulse);
        }

        // Call update frequently to process serial buffers
        if (lf_atgm336h_update(&gps)) {
            if (lf_atgm336h_has_fix(&gps)) {
                float lat, lon;
                int h, m, day, month, year;
                float s;

                lf_atgm336h_get_position(&gps, &lat, &lon);
                lf_atgm336h_get_time(&gps, &h, &m, &s);
                lf_atgm336h_get_date(&gps, &day, &month, &year);

                printf("[FIX] UTC: %02d:%02d:%05.2f | Date: %02d/%02d/%04d | Lat: %.6f, Lon: %.6f\n",
                       h, m, s, day, month, year, lat, lon);
            } else {
                printf("[NO FIX] Satellites scanning...\n");
            }
        }
        tight_loop_contents();
    }
}