1 | // I2C SRF10 or SRF08 Devantech Ultrasonic Ranger Finder
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2 | // by Nicholas Zambetti <http://www.zambetti.com>
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3 | // and James Tichenor <http://www.jamestichenor.net>
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4 |
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5 | // Demonstrates use of the Wire library reading data from the
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6 | // Devantech Utrasonic Rangers SFR08 and SFR10
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7 |
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8 | // Created 29 April 2006
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9 |
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10 | // This example code is in the public domain.
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11 |
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12 |
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13 | #include <Wire.h>
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14 |
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15 | void setup()
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16 | {
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17 | Wire.begin(); // join i2c bus (address optional for master)
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18 | Serial.begin(9600); // start serial communication at 9600bps
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19 | }
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20 |
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21 | int reading = 0;
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22 |
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23 | void loop()
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24 | {
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25 | // step 1: instruct sensor to read echoes
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26 | Wire.beginTransmission(112); // transmit to device #112 (0x70)
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27 | // the address specified in the datasheet is 224 (0xE0)
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28 | // but i2c adressing uses the high 7 bits so it's 112
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29 | Wire.write(byte(0x00)); // sets register pointer to the command register (0x00)
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30 | Wire.write(byte(0x50)); // command sensor to measure in "inches" (0x50)
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31 | // use 0x51 for centimeters
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32 | // use 0x52 for ping microseconds
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33 | Wire.endTransmission(); // stop transmitting
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34 |
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35 | // step 2: wait for readings to happen
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36 | delay(70); // datasheet suggests at least 65 milliseconds
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37 |
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38 | // step 3: instruct sensor to return a particular echo reading
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39 | Wire.beginTransmission(112); // transmit to device #112
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40 | Wire.write(byte(0x02)); // sets register pointer to echo #1 register (0x02)
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41 | Wire.endTransmission(); // stop transmitting
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42 |
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43 | // step 4: request reading from sensor
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44 | Wire.requestFrom(112, 2); // request 2 bytes from slave device #112
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45 |
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46 | // step 5: receive reading from sensor
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47 | if(2 <= Wire.available()) // if two bytes were received
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48 | {
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49 | reading = Wire.read(); // receive high byte (overwrites previous reading)
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50 | reading = reading << 8; // shift high byte to be high 8 bits
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51 | reading |= Wire.read(); // receive low byte as lower 8 bits
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52 | Serial.println(reading); // print the reading
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53 | }
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54 |
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55 | delay(250); // wait a bit since people have to read the output :)
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56 | }
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57 |
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58 |
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59 | /*
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60 |
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61 | // The following code changes the address of a Devantech Ultrasonic Range Finder (SRF10 or SRF08)
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62 | // usage: changeAddress(0x70, 0xE6);
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63 |
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64 | void changeAddress(byte oldAddress, byte newAddress)
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65 | {
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66 | Wire.beginTransmission(oldAddress);
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67 | Wire.write(byte(0x00));
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68 | Wire.write(byte(0xA0));
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69 | Wire.endTransmission();
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70 |
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71 | Wire.beginTransmission(oldAddress);
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72 | Wire.write(byte(0x00));
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73 | Wire.write(byte(0xAA));
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74 | Wire.endTransmission();
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75 |
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76 | Wire.beginTransmission(oldAddress);
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77 | Wire.write(byte(0x00));
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78 | Wire.write(byte(0xA5));
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79 | Wire.endTransmission();
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80 |
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81 | Wire.beginTransmission(oldAddress);
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82 | Wire.write(byte(0x00));
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83 | Wire.write(newAddress);
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84 | Wire.endTransmission();
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85 | }
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86 |
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87 | */
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