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    how did sudo command solved can't open device "/dev/ttyUSB0": Permission denied?

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    arduino linux nodemcu
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    • Abhay
      Abhay @arunksoman last edited by

      @arunksoman thanks for the steps
      but the thing is I don't have issues with port now, I was curious how it got resolved without going through the usual steps but by using sudo command.

      A 1 Reply Last reply Reply Quote 0
      • A
        arunksoman @Abhay last edited by arunksoman

        @Abhay What did you mean by usual steps?

        Abhay 1 Reply Last reply Reply Quote 0
        • Abhay
          Abhay @arunksoman last edited by

          @arunksoman by usual steps I meant adding our user to the group.
          ie the step
          sudo usermod -a -G dialout <username>

          A 1 Reply Last reply Reply Quote 0
          • A
            arunksoman @Abhay last edited by

            @Abhay I think most probably you might have done this earlier while installing Arduino.

            Abhay 1 Reply Last reply Reply Quote 0
            • Abhay
              Abhay @arunksoman last edited by

              @arunksoman thanks,
              I will look more into it. Thanks again

              1 Reply Last reply Reply Quote 0
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              • R

                I am trying to set up a janus webrtc to stream an RTSP to an HTML page.
                I have followed the getting-started steps by Janus-gateway official github repo.

                Since I am new to web development. I do not understand how to host the Webrtc server. can anyone guide me to set up an HTML page that can display a video stream from an RTSP server using janus webrtc?

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              • @zainmuhammed Can try capturing the GPS when the device is starting the loop instead after joining the LoRaWAN and see?

                You can put the GPS value on top of the loop or setup function.

                Also, what kind of gateway are you using? Is it configured okay, OTA is done?

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              • @salmanfaris Today I tried after connecting a 18650 cell,
                WhatsApp Image 2024-04-12 at 10.40.06_c7d1947e.jpg WhatsApp Image 2024-04-12 at 10.40.05_897b8bb6.jpg
                Data getting in console after integration of both lora and gps.
                3f45cfe7-0061-4328-8c55-ef0a73385203-image.png
                here you can see that GPS value is 0,0. also in my previous post you can see that GPS value is not reading.
                Also the status LED is active after it is connected to the satellite.

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              • Hi @zainmuhammed ,

                Can you share the GPS and LoRa output when it’s working?

                Also can try capturing the GPS when the device is starting the loop instead after joining the LoRaWAN and see?

                Also make sure the device provides have enough to modules. The GPS need more power when you cold start.

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              • @zainmuhammed
                this is the code

                #include <Arduino.h> #include <U8x8lib.h> #include <TinyGPS++.h> #include <SoftwareSerial.h> static const int RXPin = 1, TXPin = 2; static const uint32_t GPSBaud = 9600; // The TinyGPS++ object TinyGPSPlus gps; // The serial connection to the GPS device SoftwareSerial ss(RXPin, TXPin); U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(/*reset=*/U8X8_PIN_NONE); // U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/*clock=*/ SCL, /*data=*/ SDA, /*reset=*/ U8X8_PIN_NONE); // OLEDs without Reset of the Display static char recv_buf[512]; static bool is_exist = false; static bool is_join = false; static int led = 0; static int at_send_check_response(char *p_ack, int timeout_ms, char *p_cmd, ...) { int ch; int num = 0; int index = 0; int startMillis = 0; va_list args; char cmd_buffer[256]; // Adjust the buffer size as needed memset(recv_buf, 0, sizeof(recv_buf)); va_start(args, p_cmd); vsprintf(cmd_buffer, p_cmd, args); // Format the command string Serial1.print(cmd_buffer); Serial.print(cmd_buffer); va_end(args); delay(200); startMillis = millis(); if (p_ack == NULL) { return 0; } do { while (Serial1.available() > 0) { ch = Serial1.read(); recv_buf[index++] = ch; Serial.print((char)ch); delay(2); } if (strstr(recv_buf, p_ack) != NULL) { return 1; } } while (millis() - startMillis < timeout_ms); return 0; } static void recv_prase(char *p_msg) { if (p_msg == NULL) { return; } char *p_start = NULL; int data = 0; int rssi = 0; int snr = 0; p_start = strstr(p_msg, "RX"); if (p_start && (1 == sscanf(p_start, "RX: \"%d\"\r\n", &data))) { Serial.println(data); u8x8.setCursor(2, 4); u8x8.print("led :"); led = !!data; u8x8.print(led); if (led) { digitalWrite(LED_BUILTIN, LOW); } else { digitalWrite(LED_BUILTIN, HIGH); } } p_start = strstr(p_msg, "RSSI"); if (p_start && (1 == sscanf(p_start, "RSSI %d,", &rssi))) { u8x8.setCursor(0, 6); u8x8.print(" "); u8x8.setCursor(2, 6); u8x8.print("rssi:"); u8x8.print(rssi); } p_start = strstr(p_msg, "SNR"); if (p_start && (1 == sscanf(p_start, "SNR %d", &snr))) { u8x8.setCursor(0, 7); u8x8.print(" "); u8x8.setCursor(2, 7); u8x8.print("snr :"); u8x8.print(snr); } } void setup(void) { u8x8.begin(); u8x8.setFlipMode(1); u8x8.setFont(u8x8_font_chroma48medium8_r); ss.begin(GPSBaud); Serial.begin(GPSBaud); pinMode(LED_BUILTIN, OUTPUT); digitalWrite(LED_BUILTIN, HIGH); Serial1.begin(9600); Serial.print("E5 LORAWAN TEST\r\n"); u8x8.setCursor(0, 0); if (at_send_check_response("+AT: OK", 100, "AT\r\n")) { is_exist = true; at_send_check_response("+ID: DevEui", 1000, "AT+ID=DevEui,\"xxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your DevEui at_send_check_response("+ID: AppEui", 1000, "AT+ID=AppEui,\"xxxxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your AppEui at_send_check_response("+KEY: APPKEY", 1000, "AT+KEY=APPKEY,\"xxxxxxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your AppKey at_send_check_response("+ID: DevAddr", 1000, "AT+ID=DevAddr\r\n"); at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n"); at_send_check_response("+MODE: LWOTAA", 1000, "AT+MODE=LWOTAA\r\n"); at_send_check_response("+DR: IN865", 1000, "AT+DR=IN865\r\n"); // Change FREQ as per your location at_send_check_response("+CH: NUM", 1000, "AT+CH=NUM,0-2\r\n"); at_send_check_response("+CLASS: C", 1000, "AT+CLASS=A\r\n"); at_send_check_response("+PORT: 8", 1000, "AT+PORT=8\r\n"); delay(200); u8x8.setCursor(5, 0); u8x8.print("LoRaWAN"); is_join = true; } else { is_exist = false; Serial.print("No E5 module found.\r\n"); u8x8.setCursor(0, 1); u8x8.print("unfound E5 !"); } u8x8.setCursor(2, 4); u8x8.print("led :"); u8x8.print(led); } void loop(void) { if (is_exist) { int ret = 0; if (is_join) { ret = at_send_check_response("+JOIN: Network joined", 12000, "AT+JOIN\r\n"); if (ret) { is_join = false; } else { at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n"); Serial.print("JOIN failed!\r\n\r\n"); delay(5000); } } else { gps.encode(ss.read()); float a=gps.location.lat(); float b=gps.location.lng(); Serial.println(a); Serial.println(b); char cmd[128]; sprintf(cmd, "AT+CMSGHEX=\"%04X%04X\"\r\n", (float)a,(float)b); ret = at_send_check_response("Done", 5000, cmd); if (ret) { recv_prase(recv_buf); } else { Serial.print("Send failed!\r\n\r\n"); } delay(5000); } } else { delay(1000); } }

                9135d5d3-6277-4c60-81df-a2acac65c93d-image.png

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