| 1 | #include <SoftwareSerial.h>
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| 2 | #include <Wire.h>
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| 3 | #include <LiquidCrystal_I2C.h>
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| 4 | 
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| 5 | #define rxPin 2
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| 6 | #define txPin 3
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| 7 | #define DataEnablePin A0
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| 8 | 
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| 9 | #define slaveID 0xA
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| 10 | #define regRequested 33050
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| 11 | #define numRegReq 0x1
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| 12 | #define FRAMESIZE  9                                   //size of out/in array
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| 13 | 
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| 14 | float dataReceived = 0.00;
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| 15 | 
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| 16 | SoftwareSerial mySerial (rxPin, txPin);
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| 17 | uint16_t calculateCRC(uint8_t *array, uint8_t num);
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| 18 | 
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| 19 | LiquidCrystal_I2C lcd(0x3F, 20, 4);
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| 20 | 
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| 21 | void setup() {
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| 22 |   pinMode(DataEnablePin, OUTPUT);
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| 23 |   digitalWrite(DataEnablePin, LOW);
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| 24 |   mySerial.begin(9600);
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| 25 |   Serial.begin(115200);
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| 26 |   lcd.begin();
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| 27 |   lcd.backlight();
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| 28 | 
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| 29 |   Serial.println("---- STARTING ----");
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| 30 | 
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| 31 | }
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| 32 | 
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| 33 | void loop() {
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| 34 |   uint8_t modArr[9];
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| 35 | 
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| 36 |   modArr[0] = slaveID; // Slave ID
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| 37 |   modArr[1] = 0x04;    // Object type
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| 38 | 
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| 39 |   modArr[2] = highByte(regRequested);
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| 40 |   modArr[3] = lowByte(regRequested);
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| 41 | 
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| 42 |   modArr[4] = highByte(numRegReq);
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| 43 |   modArr[5] = lowByte(numRegReq);
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| 44 | 
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| 45 |   uint16_t temp = calculateCRC(modArr, FRAMESIZE - 3);
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| 46 |   modArr[6] = lowByte(temp);
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| 47 |   modArr[7] = highByte(temp);
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| 48 | 
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| 49 |   digitalWrite(DataEnablePin, HIGH);
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| 50 |   delayMicroseconds(20);
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| 51 |   mySerial.write(modArr, FRAMESIZE - 1);
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| 52 |   mySerial.flush();
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| 53 |   delayMicroseconds(10);
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| 54 |   digitalWrite(DataEnablePin, LOW);
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| 55 | 
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| 56 | 
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| 57 |   if (mySerial.available() >= FRAMESIZE) {
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| 58 | 
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| 59 |     for (uint16_t n = 0; n < FRAMESIZE - 2; n++) {
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| 60 |       modArr[n] = mySerial.read();
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| 61 |     }
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| 62 |   }
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| 63 | 
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| 64 |   if (modArr[0] == slaveID) {
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| 65 |     dataReceived = word(modArr[3], modArr[4]) / 100.00f;
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| 66 |   }
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| 67 | 
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| 68 |   lcd.print("F:");
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| 69 |   lcd.setCursor(3,0);
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| 70 |   lcd.print(dataReceived);
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| 71 |   lcd.setCursor(10,0);
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| 72 |   lcd.print("Hz");
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| 73 |   lcd.home();
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| 74 | 
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| 75 |   delay(2500);
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| 76 | 
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| 77 | }
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| 78 | 
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| 79 | uint16_t calculateCRC(uint8_t *array, uint8_t num) {
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| 80 |   uint16_t _crc, _flag;
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| 81 |   _crc = 0xFFFF;
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| 82 |   for (uint8_t i = 0; i < num; i++) {
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| 83 |     _crc = _crc ^ array[i];
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| 84 |     for (uint8_t j = 8; j; j--) {
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| 85 |       _flag = _crc & 0x0001;
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| 86 |       _crc >>= 1;
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| 87 |       if (_flag)
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| 88 |         _crc ^= 0xA001;
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| 89 |     }
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| 90 |   }
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| 91 |   return _crc;
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| 92 | }
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