meshtastic-device-ui/source/graphics/common/LoRaPresets.cpp

#include "graphics/common/LoRaPresets.h"
#include "util/ILog.h"

/**
 * LoRa Presets
 * Note: keep order the same as in meshtastic_Config_LoRaConfig_RegionCode and as in settings_region_dropdown
 */
LoRaPresets::RegionInfo LoRaPresets::regionInfo[] = {
    {"UNSET", 902.0f, 928.0f},  {"US", 902.0f, 928.0f},        {"EU_433", 433.0f, 434.0f},   {"EU_868", 869.4f, 869.65f},
    {"CN", 470.0f, 510.0f},     {"JP", 920.8f, 927.8f},        {"ANZ", 915.0f, 928.0f},      {"KR", 920.0f, 923.0f},
    {"TW", 920.0f, 925.0f},     {"RU", 868.7f, 869.2f},        {"IN", 865.0f, 867.0f},       {"NZ_865", 864.0f, 868.0f},
    {"TH", 920.0f, 925.0f},     {"LORA_24", 2400.0f, 2483.5f}, {"UA_433", 433.0f, 434.7f},   {"UA_868", 868.0f, 868.6f},
    {"MY_433", 433.0f, 435.0f}, {"MY_919", 919.0f, 924.0f},    {"SG_923", 917.0f, 925.0f},   {"PH_433", 433.0f, 434.7f},
    {"PH_868", 868.0f, 869.4f}, {"PH_915", 915.0f, 918.0f},    {"ANZ_433", 433.05f, 434.79f}};

LoRaPresets::ModemPreset LoRaPresets::modemPreset[] = {
    {"LongFast", "250", .250f},   {"LongSlow", "125", .125f},  {"VLongSlow", "62.5", .0625f}, {"MediumSlow", "250", .250f},
    {"MediumFast", "250", .250f}, {"ShortSlow", "250", .250f}, {"ShortFast", "250", .250f},   {"LongMod", "125", .125f},
    {"ShortTurbo", "500", .500f}, {"LongTurbo", "500", .500f}};

const char *LoRaPresets::loRaRegionToString(meshtastic_Config_LoRaConfig_RegionCode region)
{
    return regionInfo[region].region;
}

float LoRaPresets::getFrequencyStart(meshtastic_Config_LoRaConfig_RegionCode region)
{
    return regionInfo[region].freqStart;
}

float LoRaPresets::getFrequencyEnd(meshtastic_Config_LoRaConfig_RegionCode region)
{
    return regionInfo[region].freqEnd;
}

/**
 * Default slot number is generated using the same firmware hash algorithm
 */
uint16_t LoRaPresets::getDefaultSlot(meshtastic_Config_LoRaConfig_RegionCode region,
                                     meshtastic_Config_LoRaConfig_ModemPreset preset, const char *channelName)
{
    auto hash = [](const char *str) -> uint32_t {
        uint32_t hash = 5381;
        unsigned char c;
        while ((c = *str++) != '\0')
            hash += (hash << 5) + c;
        return hash;
    };

    uint32_t numChannels = getNumChannels(region, preset);
    return numChannels == 0
               ? (region == meshtastic_Config_LoRaConfig_RegionCode_UNSET ? 0 : 1)
               : hash(channelName && channelName[0] != '\0' ? channelName : modemPreset[preset].preset) % numChannels + 1;
}

float LoRaPresets::getBandwidth(meshtastic_Config_LoRaConfig_ModemPreset preset)
{
    // TODO: LORA_24 wide mode (3.25 vs. 31/.03125f, 62/.0625f, 200/.203125f, 400/.40625f, 800/.8125f, 1600/1.6250f
    return modemPreset[preset].bandwidth_MHz;
}

const char *LoRaPresets::getBandwidthString(meshtastic_Config_LoRaConfig_ModemPreset preset)
{
    return modemPreset[preset].bandwidth_kHz;
}

const char *LoRaPresets::modemPresetToString(meshtastic_Config_LoRaConfig_ModemPreset preset)
{
    return modemPreset[preset].preset;
}

uint32_t LoRaPresets::getNumChannels(meshtastic_Config_LoRaConfig_RegionCode region,
                                     meshtastic_Config_LoRaConfig_ModemPreset preset)
{
    return (region == meshtastic_Config_LoRaConfig_RegionCode_UNSET
                ? 0
                : uint32_t((regionInfo[region].freqEnd - regionInfo[region].freqStart) / modemPreset[preset].bandwidth_MHz));
}

float LoRaPresets::getRadioFreq(meshtastic_Config_LoRaConfig_RegionCode region, meshtastic_Config_LoRaConfig_ModemPreset preset,
                                uint32_t channel)
{
    return (regionInfo[region].freqStart + modemPreset[preset].bandwidth_MHz / 2) +
           (channel - 1) * modemPreset[preset].bandwidth_MHz;
}