Garbled packets on Heltec wifi lora stick v3

[chedim]

Boards: https://heltec.org/project/wireless-stick-v3/ Trying to send "hello" messages between the two of these and instead receiving garbled (seemingly not random as they repeat) characters:

loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: ?@m$
loragate/debug [D][lora_mqtt_bridge.sensor:070]: Packet size: 5
loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: z?H?
loragate/debug [D][lora_mqtt_bridge.sensor:070]: Packet size: 5
loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: z?H?
loragate/debug [D][lora_mqtt_bridge.sensor:070]: Packet size: 5
loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: ???s
loragate/debug [D][lora_mqtt_bridge.sensor:070]: Packet size: 5
loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: ???s
loragate/debug [D][lora_mqtt_bridge.sensor:070]: Packet size: 5
loragate/debug [D][lora_mqtt_bridge.sensor:101]: received packet: ???s

Transmitter initialization code:

        if (!LoRa.begin(cs_pin, reset_pin, busy_pin, dio0_pin, -1, -1)) {
            ESP_LOGE(TAG, "Failed to setup LoRa, mode: %d, error: %d", LoRa.getMode(), LoRa.getError());
            this->mark_failed();
            return;
        }

        uint8_t dio3Voltage = SX126X_DIO3_OUTPUT_1_8;
        uint32_t tcxoDelay = SX126X_TCXO_DELAY_10;
        LoRa.setDio3TcxoCtrl(dio3Voltage, tcxoDelay);
        LoRa.setTxPower(17, SX126X_TX_POWER_SX1262);                        // TX power +17 dBm for SX1262

            LoRa.setSyncWord(_sync);
        LoRa.setFrequency(_frequency);
        ESP_LOGI(TAG, "LoRa Modulation: spread=%d, bandwidth=%d, coding=%d", _spread, _bandwidth, _coding);
        LoRa.setLoRaModulation(_spread, _bandwidth, _coding, false);

        uint8_t headerType = SX126X_HEADER_EXPLICIT;                        // Explicit header mode
        uint16_t preambleLength = 12;                                       // Set preamble length to 12
        uint8_t payloadLength = 255;                                         // Initialize payloadLength to 15
        bool crcType = false;                                                // Set CRC enable
        LoRa.setLoRaPacket(headerType, preambleLength, payloadLength, crcType);

Transmitter code:

            LoRa.beginPacket();
        LoRa.write("hello", 5);

            if (LoRa.endPacket(20)) 
            ESP_LOGI(TAG, "sent a packet");
        else {
            ESP_LOGW(TAG, "failed to send a packet");
            return;
        }

        LoRa.wait(200);

---

Receiver initialization code:

        if (!LoRa.begin(cs_pin, reset_pin, busy_pin, dio0_pin, -1, -1)) {
            ESP_LOGE(TAG, "Failed to setup LoRa, mode: %d, error: %d", LoRa.getMode(), LoRa.getError());
            this->mark_failed();
            return;
        }

          // Configure TCXO or XTAL used in RF module
          uint8_t dio3Voltage = SX126X_DIO3_OUTPUT_1_8;
          uint32_t tcxoDelay = SX126X_TCXO_DELAY_10;
          LoRa.setDio3TcxoCtrl(dio3Voltage, tcxoDelay);
          // Set RX gain to boosted gain
          LoRa.setRxGain(SX126X_RX_GAIN_BOOSTED);

        LoRa.setFrequency(_frequency);
        ESP_LOGI(TAG, "LoRa Modulation: spread=%d, bandwidth=%d, coding=%d", _spread, _bandwidth, _coding);
        LoRa.setLoRaModulation(_spread, _bandwidth, _coding, false);
        LoRa.setSyncWord(_sync);

        uint8_t headerType = SX126X_HEADER_EXPLICIT;                        // Explicit header mode
        uint16_t preambleLength = 12;                                       // Set preamble length to 12
        uint8_t payloadLength = 255;                                         // Initialize payloadLength to 15
        bool crcType = false;                                                // Set CRC enable
        LoRa.setLoRaPacket(headerType, preambleLength, payloadLength, crcType);

        if (!LoRa.request(SX126X_RX_CONTINUOUS)) {
            ESP_LOGE(TAG, "Failed to request continuous listening");
            this->mark_failed();
            return;
        }
        ESP_LOGI(TAG, "Initialized LoRa");

Receiver code:

        size_t _packet_size = LoRa.available();
        if (_packet_size == 0) {
            return;
        }
        ESP_LOGD(TAG, "Packet size: %d", _packet_size);
                char received_string[_packet_size];

                // received data
        for(int i = 0; i < _packet_size; i++) {
            received_string[i] = LoRa.read();
        }

                ESP_LOGI(TAG, "received packet: %s", received_string);

Spent the whole day trying to figure out waidw. Please help, thank you!

[m4mans]

@chedim Did you find the issue?

Getting similar packets with LLCC68.