root / arduino-1.0 / libraries / Wire / examples / SFRRanger_reader / SFRRanger_reader.ino @ 58d82c77
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1 | 58d82c77 | Tom Mullins | // 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 | |||
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 | |||
8 | // Created 29 April 2006 |
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9 | |||
10 | // This example code is in the public domain. |
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11 | |||
12 | |||
13 | #include <Wire.h> |
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14 | |||
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 | |||
21 | int reading = 0; |
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22 | |||
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 | |||
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 | |||
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 | |||
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 | |||
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 | |||
55 | delay(250); // wait a bit since people have to read the output :) |
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56 | } |
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57 | |||
58 | |||
59 | /* |
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60 | |||
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 | |||
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 | |||
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 | |||
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 | |||
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 | |||
87 | */ |