How can i define daud rate in avr microcontrollers ?
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while learning the USART communication in avr setting baud rate part seems little confusing to me .
There are two registers for setting baud rate UBRROH AND UBBRROL
How Can i use these registers...? -
Hi @Richu-Bini, The Uart Baud Rate Register (UBRR) is used to set the clock for the UART shift registers and For standard crystal and resonator frequencies, the most commonly used baud rates for asynchronous operation can be generated by using the UBRR settings provided by the AVR Datasheet: AVR306: Using the AVR USART on tinyAVR and megaAVR devices
And you can find the equation from the datasheet to calculate the UBRR values depends on the clock source it has.
more details at the AVR306: Using the AVR USART on tinyAVR and
megaAVR devices
src: http://www.avrbeginners.net/architecture/uart/uart.html#baud_generatorresource:
Recent Posts
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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,
Data getting in console after integration of both lora and gps.
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. -
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
#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); } }
this is the code