/** * @file LoRaPHYUS915Hybrid.cpp * * @brief Implements LoRaPHY for US 915 MHz Hybrid band * * \code * ______ _ * / _____) _ | | * ( (____ _____ ____ _| |_ _____ ____| |__ * \____ \| ___ | (_ _) ___ |/ ___) _ \ * _____) ) ____| | | || |_| ____( (___| | | | * (______/|_____)_|_|_| \__)_____)\____)_| |_| * (C)2013 Semtech * ___ _____ _ ___ _ _____ ___ ___ ___ ___ * / __|_ _/_\ / __| |/ / __/ _ \| _ \/ __| __| * \__ \ | |/ _ \ (__| ' <| _| (_) | / (__| _| * |___/ |_/_/ \_\___|_|\_\_| \___/|_|_\\___|___| * embedded.connectivity.solutions=============== * * \endcode * * * License: Revised BSD License, see LICENSE.TXT file include in the project * * Maintainer: Miguel Luis ( Semtech ), Gregory Cristian ( Semtech ) and Daniel Jaeckle ( STACKFORCE ) * * Copyright (c) 2017, Arm Limited and affiliates. * SPDX-License-Identifier: BSD-3-Clause * */ #include "LoRaPHYUS915Hybrid.h" #include "lora_phy_ds.h" /*! * Minimal datarate that can be used by the node */ #define US915_HYBRID_TX_MIN_DATARATE DR_0 /*! * Maximal datarate that can be used by the node */ #define US915_HYBRID_TX_MAX_DATARATE DR_4 /*! * Minimal datarate that can be used by the node */ #define US915_HYBRID_RX_MIN_DATARATE DR_8 /*! * Maximal datarate that can be used by the node */ #define US915_HYBRID_RX_MAX_DATARATE DR_13 /*! * Default datarate used by the node */ #define US915_HYBRID_DEFAULT_DATARATE DR_0 /*! * Minimal Rx1 receive datarate offset */ #define US915_HYBRID_MIN_RX1_DR_OFFSET 0 /*! * Maximal Rx1 receive datarate offset */ #define US915_HYBRID_MAX_RX1_DR_OFFSET 3 /*! * Default Rx1 receive datarate offset */ #define US915_HYBRID_DEFAULT_RX1_DR_OFFSET 0 /*! * Minimal Tx output power that can be used by the node */ #define US915_HYBRID_MIN_TX_POWER TX_POWER_10 /*! * Maximal Tx output power that can be used by the node */ #define US915_HYBRID_MAX_TX_POWER TX_POWER_0 /*! * Default Tx output power used by the node */ #define US915_HYBRID_DEFAULT_TX_POWER TX_POWER_0 /*! * Default Max ERP */ #define US915_HYBRID_DEFAULT_MAX_ERP 30.0f /*! * ADR Ack limit */ #define US915_HYBRID_ADR_ACK_LIMIT 64 /*! * ADR Ack delay */ #define US915_HYBRID_ADR_ACK_DELAY 32 /*! * Enabled or disabled the duty cycle */ #define US915_HYBRID_DUTY_CYCLE_ENABLED 0 /*! * Maximum RX window duration */ #define US915_HYBRID_MAX_RX_WINDOW 3000 /*! * Receive delay 1 */ #define US915_HYBRID_RECEIVE_DELAY1 1000 /*! * Receive delay 2 */ #define US915_HYBRID_RECEIVE_DELAY2 2000 /*! * Join accept delay 1 */ #define US915_HYBRID_JOIN_ACCEPT_DELAY1 5000 /*! * Join accept delay 2 */ #define US915_HYBRID_JOIN_ACCEPT_DELAY2 6000 /*! * Maximum frame counter gap */ #define US915_HYBRID_MAX_FCNT_GAP 16384 /*! * Ack timeout */ #define US915_HYBRID_ACKTIMEOUT 2000 /*! * Random ack timeout limits */ #define US915_HYBRID_ACK_TIMEOUT_RND 1000 /*! * Second reception window channel frequency definition. */ #define US915_HYBRID_RX_WND_2_FREQ 923300000 /*! * Second reception window channel datarate definition. */ #define US915_HYBRID_RX_WND_2_DR DR_8 /*! * Band 0 definition * { DutyCycle, TxMaxPower, LastJoinTxDoneTime, LastTxDoneTime, TimeOff } */ static const band_t US915_HYBRID_BAND0 = { 1, US915_HYBRID_MAX_TX_POWER, 0, 0, 0 }; // 100.0 % /*! * Defines the first channel for RX window 1 for US band */ #define US915_HYBRID_FIRST_RX1_CHANNEL ( (uint32_t) 923300000 ) /*! * Defines the last channel for RX window 1 for US band */ #define US915_HYBRID_LAST_RX1_CHANNEL ( (uint32_t) 927500000 ) /*! * Defines the step width of the channels for RX window 1 */ #define US915_HYBRID_STEPWIDTH_RX1_CHANNEL ( (uint32_t) 600000 ) /*! * Data rates table definition */ static const uint8_t datarates_US915_HYBRID[] = { 10, 9, 8, 7, 8, 0, 0, 0, 12, 11, 10, 9, 8, 7, 0, 0 }; /*! * Bandwidths table definition in Hz */ static const uint32_t bandwidths_US915_HYBRID[] = { 125000, 125000, 125000, 125000, 500000, 0, 0, 0, 500000, 500000, 500000, 500000, 500000, 500000, 0, 0 }; /*! * Up/Down link data rates offset definition */ static const int8_t datarate_offsets_US915_HYBRID[5][4] = { { DR_10, DR_9 , DR_8 , DR_8 }, // DR_0 { DR_11, DR_10, DR_9 , DR_8 }, // DR_1 { DR_12, DR_11, DR_10, DR_9 }, // DR_2 { DR_13, DR_12, DR_11, DR_10 }, // DR_3 { DR_13, DR_13, DR_12, DR_11 }, // DR_4 }; /*! * Maximum payload with respect to the datarate index. Cannot operate with repeater. */ static const uint8_t max_payloads_US915_HYBRID[] = { 11, 53, 125, 242, 242, 0, 0, 0, 53, 129, 242, 242, 242, 242, 0, 0 }; /*! * Maximum payload with respect to the datarate index. Can operate with repeater. */ static const uint8_t max_payloads_with_repeater_US915_HYBRID[] = { 11, 53, 125, 242, 242, 0, 0, 0, 33, 109, 222, 222, 222, 222, 0, 0 }; LoRaPHYUS915Hybrid::LoRaPHYUS915Hybrid(LoRaWANTimeHandler &lora_time) : LoRaPHY(lora_time) { bands[0] = US915_HYBRID_BAND0; // Channels // 125 kHz channels for (uint8_t i = 0; i < US915_HYBRID_MAX_NB_CHANNELS - 8; i++) { channels[i].frequency = 902300000 + i * 200000; channels[i].dr_range.value = ( DR_3 << 4 ) | DR_0; channels[i].band = 0; } // 500 kHz channels for (uint8_t i = US915_HYBRID_MAX_NB_CHANNELS - 8; i < US915_HYBRID_MAX_NB_CHANNELS; i++) { channels[i].frequency = 903000000 + (i - (US915_HYBRID_MAX_NB_CHANNELS - 8)) * 1600000; channels[i].dr_range.value = ( DR_4 << 4 ) | DR_4; channels[i].band = 0; } // ChannelsMask default_channel_mask[0] = 0x00FF; default_channel_mask[1] = 0x0000; default_channel_mask[2] = 0x0000; default_channel_mask[3] = 0x0000; default_channel_mask[4] = 0x0001; memset(channel_mask, 0, sizeof(channel_mask)); memset(current_channel_mask, 0, sizeof(current_channel_mask)); // Copy channels default mask copy_channel_mask(channel_mask, default_channel_mask, US915_HYBRID_CHANNEL_MASK_SIZE); // Copy into channels mask remaining copy_channel_mask(current_channel_mask, channel_mask, US915_HYBRID_CHANNEL_MASK_SIZE); // set default channels phy_params.channels.channel_list = channels; phy_params.channels.channel_list_size = US915_HYBRID_MAX_NB_CHANNELS; phy_params.channels.mask = channel_mask; phy_params.channels.default_mask = default_channel_mask; phy_params.channels.mask_size = US915_HYBRID_CHANNEL_MASK_SIZE; // set bands for US915_HYBRID spectrum phy_params.bands.table = (void *) bands; phy_params.bands.size = US915_HYBRID_MAX_NB_BANDS; // set bandwidths available in US915_HYBRID spectrum phy_params.bandwidths.table = (void *) bandwidths_US915_HYBRID; phy_params.bandwidths.size = 16; // set data rates available in US915_HYBRID spectrum phy_params.datarates.table = (void *) datarates_US915_HYBRID; phy_params.datarates.size = 16; // set payload sizes with respect to data rates phy_params.payloads.table = (void *) max_payloads_US915_HYBRID; phy_params.payloads.size = 16; phy_params.payloads_with_repeater.table = (void *) max_payloads_with_repeater_US915_HYBRID; phy_params.payloads_with_repeater.size = 16; // dwell time setting phy_params.ul_dwell_time_setting = 0; phy_params.dl_dwell_time_setting = 0; // set initial and default parameters phy_params.duty_cycle_enabled = US915_HYBRID_DUTY_CYCLE_ENABLED; phy_params.accept_tx_param_setup_req = false; phy_params.fsk_supported = false; phy_params.cflist_supported = false; phy_params.dl_channel_req_supported = false; phy_params.custom_channelplans_supported = false; phy_params.default_channel_cnt = US915_HYBRID_MAX_NB_CHANNELS; phy_params.max_channel_cnt = US915_HYBRID_MAX_NB_CHANNELS; phy_params.cflist_channel_cnt = 0; phy_params.min_tx_datarate = US915_HYBRID_TX_MIN_DATARATE; phy_params.max_tx_datarate = US915_HYBRID_TX_MAX_DATARATE; phy_params.min_rx_datarate = US915_HYBRID_RX_MIN_DATARATE; phy_params.max_rx_datarate = US915_HYBRID_RX_MAX_DATARATE; phy_params.default_datarate = US915_HYBRID_DEFAULT_DATARATE; phy_params.default_max_datarate = US915_HYBRID_TX_MAX_DATARATE; phy_params.min_rx1_dr_offset = US915_HYBRID_MIN_RX1_DR_OFFSET; phy_params.max_rx1_dr_offset = US915_HYBRID_MAX_RX1_DR_OFFSET; phy_params.default_rx1_dr_offset = US915_HYBRID_DEFAULT_RX1_DR_OFFSET; phy_params.min_tx_power = US915_HYBRID_MIN_TX_POWER; phy_params.max_tx_power = US915_HYBRID_MAX_TX_POWER; phy_params.default_tx_power = US915_HYBRID_DEFAULT_TX_POWER; phy_params.default_max_eirp = 0; phy_params.default_antenna_gain = 0; phy_params.adr_ack_limit = US915_HYBRID_ADR_ACK_LIMIT; phy_params.adr_ack_delay = US915_HYBRID_ADR_ACK_DELAY; phy_params.max_rx_window = US915_HYBRID_MAX_RX_WINDOW; phy_params.recv_delay1 = US915_HYBRID_RECEIVE_DELAY1; phy_params.recv_delay2 = US915_HYBRID_RECEIVE_DELAY2; phy_params.join_accept_delay1 = US915_HYBRID_JOIN_ACCEPT_DELAY1; phy_params.join_accept_delay2 = US915_HYBRID_JOIN_ACCEPT_DELAY2; phy_params.max_fcnt_gap = US915_HYBRID_MAX_FCNT_GAP; phy_params.ack_timeout = US915_HYBRID_ACKTIMEOUT; phy_params.ack_timeout_rnd = US915_HYBRID_ACK_TIMEOUT_RND; phy_params.rx_window2_datarate = US915_HYBRID_RX_WND_2_DR; phy_params.rx_window2_frequency = US915_HYBRID_RX_WND_2_FREQ; } LoRaPHYUS915Hybrid::~LoRaPHYUS915Hybrid() { } void LoRaPHYUS915Hybrid::restore_default_channels() { // Copy channels default mask copy_channel_mask(channel_mask, default_channel_mask, US915_HYBRID_CHANNEL_MASK_SIZE); for (uint8_t i = 0; i < US915_HYBRID_CHANNEL_MASK_SIZE; i++) { // Copy-And the channels mask current_channel_mask[i] &= channel_mask[i]; } } bool LoRaPHYUS915Hybrid::get_next_ADR(bool restore_channel_mask, int8_t& dr_out, int8_t& tx_power_out, uint32_t& adr_ack_cnt) { bool adrAckReq = false; uint16_t ack_limit_plus_delay = phy_params.adr_ack_limit + phy_params.adr_ack_delay; if (dr_out == phy_params.min_tx_datarate) { adr_ack_cnt = 0; return adrAckReq; } if (adr_ack_cnt < phy_params.adr_ack_limit) { return adrAckReq; } // ADR ack counter is larger than ADR-ACK-LIMIT adrAckReq = true; tx_power_out = phy_params.max_tx_power; if (adr_ack_cnt >= ack_limit_plus_delay) { if ((adr_ack_cnt % phy_params.adr_ack_delay) == 1) { // Decrease the datarate dr_out = get_next_lower_tx_datarate(dr_out); if (dr_out == phy_params.min_tx_datarate) { // We must set adrAckReq to false as soon as we reach the lowest datarate adrAckReq = false; if (restore_channel_mask) { // Re-enable default channels reenable_500khz_channels(channel_mask[4], channel_mask); } } } } return adrAckReq; } bool LoRaPHYUS915Hybrid::rx_config(rx_config_params_t* config) { int8_t dr = config->datarate; uint8_t max_payload = 0; int8_t phy_dr = 0; uint32_t frequency = config->frequency; _radio->lock(); if (_radio->get_status() != RF_IDLE) { _radio->unlock(); return false; } _radio->unlock(); if (config->rx_slot == RX_SLOT_WIN_1) { // Apply window 1 frequency frequency = US915_HYBRID_FIRST_RX1_CHANNEL + (config->channel % 8) * US915_HYBRID_STEPWIDTH_RX1_CHANNEL; } // Read the physical datarate from the datarates table phy_dr = datarates_US915_HYBRID[dr]; _radio->lock(); _radio->set_channel( frequency ); // Radio configuration _radio->set_rx_config(MODEM_LORA, config->bandwidth, phy_dr, 1, 0, 8, config->window_timeout, false, 0, false, 0, 0, true, config->is_rx_continuous); _radio->unlock(); if (config->is_repeater_supported == true) { max_payload = max_payloads_with_repeater_US915_HYBRID[dr]; } else { max_payload = max_payloads_US915_HYBRID[dr]; } _radio->lock(); _radio->set_max_payload_length(MODEM_LORA, max_payload + LORA_MAC_FRMPAYLOAD_OVERHEAD); _radio->unlock(); return true; } bool LoRaPHYUS915Hybrid::tx_config(tx_config_params_t* config, int8_t* tx_power, lorawan_time_t* tx_toa) { int8_t phy_dr = datarates_US915_HYBRID[config->datarate]; int8_t tx_power_limited = limit_tx_power(config->tx_power, bands[channels[config->channel].band].max_tx_pwr, config->datarate); uint32_t bandwidth = get_bandwidth (config->datarate); int8_t phy_tx_power = 0; // Calculate physical TX power phy_tx_power = compute_tx_power(tx_power_limited, US915_HYBRID_DEFAULT_MAX_ERP, 0); _radio->lock(); _radio->set_channel( channels[config->channel].frequency ); _radio->set_tx_config(MODEM_LORA, phy_tx_power, 0, bandwidth, phy_dr, 1, 8, false, true, 0, 0, false, 3000); // Setup maximum payload lenght of the radio driver _radio->set_max_payload_length(MODEM_LORA, config->pkt_len); // Get the time-on-air of the next tx frame *tx_toa = _radio->time_on_air(MODEM_LORA, config->pkt_len); _radio->unlock(); *tx_power = tx_power_limited; return true; } uint8_t LoRaPHYUS915Hybrid::link_ADR_request(adr_req_params_t* params, int8_t* dr_out, int8_t* tx_power_out, uint8_t* nb_rep_out, uint8_t* nb_bytes_parsed) { uint8_t status = 0x07; link_adr_params_t adr_settings; uint8_t next_idx = 0; uint8_t bytes_processed = 0; uint16_t temp_channel_mask[US915_HYBRID_CHANNEL_MASK_SIZE] = {0, 0, 0, 0, 0}; verify_adr_params_t verify_params; // Initialize local copy of channels mask copy_channel_mask(temp_channel_mask, channel_mask, US915_HYBRID_CHANNEL_MASK_SIZE); while (bytes_processed < params->payload_size) { next_idx = parse_link_ADR_req(&(params->payload[bytes_processed]), &adr_settings); if (next_idx == 0) { break; // break loop, since no more request has been found } // Update bytes processed bytes_processed += next_idx; // Revert status, as we only check the last ADR request for the channel mask KO status = 0x07; if (adr_settings.ch_mask_ctrl == 6) { // Enable all 125 kHz channels temp_channel_mask[0] = 0xFFFF; temp_channel_mask[1] = 0xFFFF; temp_channel_mask[2] = 0xFFFF; temp_channel_mask[3] = 0xFFFF; // Apply chMask to channels 64 to 71 temp_channel_mask[4] = adr_settings.channel_mask; } else if( adr_settings.ch_mask_ctrl == 7 ) { // Disable all 125 kHz channels temp_channel_mask[0] = 0x0000; temp_channel_mask[1] = 0x0000; temp_channel_mask[2] = 0x0000; temp_channel_mask[3] = 0x0000; // Apply chMask to channels 64 to 71 temp_channel_mask[4] = adr_settings.channel_mask; } else if( adr_settings.ch_mask_ctrl == 5 ) { // RFU status &= 0xFE; // Channel mask KO } else { temp_channel_mask[adr_settings.ch_mask_ctrl] = adr_settings.channel_mask; } } // FCC 15.247 paragraph F mandates to hop on at least 2 125 kHz channels if ((adr_settings.datarate < DR_4) && (num_active_channels( temp_channel_mask, 0, 4 ) < 2)) { status &= 0xFE; // Channel mask KO } if( validate_channel_mask(temp_channel_mask ) == false) { status &= 0xFE; // Channel mask KO } verify_params.status = status; verify_params.adr_enabled = params->adr_enabled; verify_params.datarate = adr_settings.datarate; verify_params.tx_power = adr_settings.tx_power; verify_params.nb_rep = adr_settings.nb_rep; verify_params.current_datarate = params->current_datarate; verify_params.current_tx_power = params->current_tx_power; verify_params.current_nb_rep = params->current_nb_rep; verify_params.channel_mask = temp_channel_mask; // Verify the parameters and update, if necessary status = verify_link_ADR_req(&verify_params, &adr_settings.datarate, &adr_settings.tx_power, &adr_settings.nb_rep); // Update channelsMask if everything is correct if (status == 0x07) { // Copy Mask copy_channel_mask(channel_mask, temp_channel_mask, US915_HYBRID_CHANNEL_MASK_SIZE); current_channel_mask[0] &= channel_mask[0]; current_channel_mask[1] &= channel_mask[1]; current_channel_mask[2] &= channel_mask[2]; current_channel_mask[3] &= channel_mask[3]; current_channel_mask[4] = channel_mask[4]; } // Update status variables *dr_out = adr_settings.datarate; *tx_power_out = adr_settings.tx_power; *nb_rep_out = adr_settings.nb_rep; *nb_bytes_parsed = bytes_processed; return status; } uint8_t LoRaPHYUS915Hybrid::accept_rx_param_setup_req(rx_param_setup_req_t* params) { uint8_t status = 0x07; uint32_t freq = params->frequency; // Verify radio frequency if ((_radio->check_rf_frequency(freq) == false) || (freq < US915_HYBRID_FIRST_RX1_CHANNEL) || (freq > US915_HYBRID_LAST_RX1_CHANNEL) || (((freq - ( uint32_t ) US915_HYBRID_FIRST_RX1_CHANNEL) % (uint32_t) US915_HYBRID_STEPWIDTH_RX1_CHANNEL) != 0)) { status &= 0xFE; // Channel frequency KO } // Verify datarate if (val_in_range(params->datarate, US915_HYBRID_RX_MIN_DATARATE, US915_HYBRID_RX_MAX_DATARATE) == 0) { status &= 0xFD; // Datarate KO } if ((val_in_range(params->datarate, DR_5, DR_7) == 1) || (params->datarate > DR_13)) { status &= 0xFD; // Datarate KO } // Verify datarate offset if (val_in_range(params->dr_offset, US915_HYBRID_MIN_RX1_DR_OFFSET, US915_HYBRID_MAX_RX1_DR_OFFSET) == 0) { status &= 0xFB; // Rx1DrOffset range KO } return status; } int8_t LoRaPHYUS915Hybrid::get_alternate_DR(uint8_t nb_trials) { int8_t datarate = 0; // Re-enable 500 kHz default channels reenable_500khz_channels(channel_mask[4], channel_mask); if ((nb_trials & 0x01) == 0x01) { datarate = DR_4; } else { datarate = DR_0; } return datarate; } lorawan_status_t LoRaPHYUS915Hybrid::set_next_channel(channel_selection_params_t* params, uint8_t* channel, lorawan_time_t* time, lorawan_time_t* aggregate_timeOff) { uint8_t nb_enabled_channels = 0; uint8_t delay_tx = 0; uint8_t enabled_channels[US915_HYBRID_MAX_NB_CHANNELS] = {0}; lorawan_time_t next_tx_delay = 0; // Count 125kHz channels if (num_active_channels(current_channel_mask, 0, 4) == 0) { // Reactivate default channels copy_channel_mask(current_channel_mask, channel_mask, 4); } // Check other channels if (params->current_datarate >= DR_4) { if ((current_channel_mask[4] & 0x00FF ) == 0) { current_channel_mask[4] = channel_mask[4]; } } if (params->aggregate_timeoff <= _lora_time.get_elapsed_time( params->last_aggregate_tx_time)) { // Reset Aggregated time off *aggregate_timeOff = 0; // Update bands Time OFF next_tx_delay = update_band_timeoff(params->joined, params->dc_enabled, bands, US915_HYBRID_MAX_NB_BANDS); // Search how many channels are enabled nb_enabled_channels = enabled_channel_count(params->joined, params->current_datarate, current_channel_mask, enabled_channels, &delay_tx); } else { delay_tx++; next_tx_delay = params->aggregate_timeoff - _lora_time.get_elapsed_time(params->last_aggregate_tx_time); } if (nb_enabled_channels > 0) { // We found a valid channel *channel = enabled_channels[get_random(0, nb_enabled_channels - 1)]; // Disable the channel in the mask disable_channel(current_channel_mask, *channel, US915_HYBRID_MAX_NB_CHANNELS - 8); *time = 0; return LORAWAN_STATUS_OK; } else { if (delay_tx > 0) { // Delay transmission due to AggregatedTimeOff or to a band time off *time = next_tx_delay; return LORAWAN_STATUS_DUTYCYCLE_RESTRICTED; } // Datarate not supported by any channel *time = 0; return LORAWAN_STATUS_NO_CHANNEL_FOUND; } } void LoRaPHYUS915Hybrid::set_tx_cont_mode(cw_mode_params_t* params, uint32_t given_frequency) { (void)given_frequency; int8_t tx_power_limited = limit_tx_power(params->tx_power, bands[channels[params->channel].band].max_tx_pwr, params->datarate); int8_t phy_tx_power = 0; uint32_t frequency = channels[params->channel].frequency; // Calculate physical TX power phy_tx_power = compute_tx_power(tx_power_limited, US915_HYBRID_DEFAULT_MAX_ERP, 0); _radio->lock(); _radio->set_tx_continuous_wave(frequency, phy_tx_power, params->timeout); _radio->unlock(); } uint8_t LoRaPHYUS915Hybrid::apply_DR_offset(int8_t dr, int8_t drOffset) { int8_t datarate = datarate_offsets_US915_HYBRID[dr][drOffset]; if (datarate < 0) { datarate = DR_0; } return datarate; } void LoRaPHYUS915Hybrid::reenable_500khz_channels(uint16_t mask, uint16_t* channelsMask) { uint16_t blockMask = mask; for (uint8_t i = 0, j = 0; i < 4; i++, j += 2) { channelsMask[i] = 0; if ((blockMask & (1 << j)) != 0) { channelsMask[i] |= 0x00FF; } if ((blockMask & (1 << (j + 1))) != 0) { channelsMask[i] |= 0xFF00; } } channelsMask[4] = blockMask; } int8_t LoRaPHYUS915Hybrid::limit_tx_power(int8_t txPower, int8_t maxBandTxPower, int8_t datarate) { int8_t txPowerResult = txPower; // Limit tx power to the band max txPowerResult = MAX(txPower, maxBandTxPower); if (datarate == DR_4) { // Limit tx power to max 26dBm txPowerResult = MAX(txPower, TX_POWER_2); } else { if (num_active_channels(channel_mask, 0, 4) < 50) { // Limit tx power to max 21dBm txPowerResult = MAX(txPower, TX_POWER_5); } } return txPowerResult; } bool LoRaPHYUS915Hybrid::validate_channel_mask(uint16_t* channel_masks) { bool mask_state = false; uint16_t block1 = 0; uint16_t block2 = 0; uint8_t index = 0; uint16_t temp_channel_masks[US915_HYBRID_CHANNEL_MASK_SIZE]; // Copy channels mask to not change the input for (uint8_t i = 0; i < 4; i++) { temp_channel_masks[i] = channel_masks[i]; } for(uint8_t i = 0; i < 4; i++) { block1 = temp_channel_masks[i] & 0x00FF; block2 = temp_channel_masks[i] & 0xFF00; if (count_bits(block1, 16) > 1) { temp_channel_masks[i] &= block1; temp_channel_masks[4] = 1 << ( i * 2 ); mask_state = true; index = i; break; } else if( count_bits( block2, 16 ) > 1 ) { temp_channel_masks[i] &= block2; temp_channel_masks[4] = 1 << ( i * 2 + 1 ); mask_state = true; index = i; break; } } // Do change the channel mask, if we have found a valid block. if (mask_state == true) { // Copy channels mask back again for (uint8_t i = 0; i < 4; i++) { channel_masks[i] = temp_channel_masks[i]; if (i != index) { channel_masks[i] = 0; } } channel_masks[4] = temp_channel_masks[4]; } return mask_state; }