Dev Joshi
SRF02 Ultrasonic range finder library
SRF02.cpp@0:f0cf55dd23f6, 2011-05-02 (annotated)
- Committer:
- go2dev
- Date:
- Mon May 02 18:44:46 2011 +0000
- Revision:
- 0:f0cf55dd23f6
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| go2dev | 0:f0cf55dd23f6 | 1 | /*Library for SRF02 ultrasonic range finder*/ |
| go2dev | 0:f0cf55dd23f6 | 2 | #include "SRF02.h" |
| go2dev | 0:f0cf55dd23f6 | 3 | |
| go2dev | 0:f0cf55dd23f6 | 4 | SRF02::SRF02(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr){ |
| go2dev | 0:f0cf55dd23f6 | 5 | //no initialisation code required here |
| go2dev | 0:f0cf55dd23f6 | 6 | } |
| go2dev | 0:f0cf55dd23f6 | 7 | |
| go2dev | 0:f0cf55dd23f6 | 8 | SRF02::~SRF02(){ |
| go2dev | 0:f0cf55dd23f6 | 9 | |
| go2dev | 0:f0cf55dd23f6 | 10 | } |
| go2dev | 0:f0cf55dd23f6 | 11 | |
| go2dev | 0:f0cf55dd23f6 | 12 | float SRF02::distancecm(){ |
| go2dev | 0:f0cf55dd23f6 | 13 | //local variables |
| go2dev | 0:f0cf55dd23f6 | 14 | const char m_addr = 0xE0; //srf02 default slave address |
| go2dev | 0:f0cf55dd23f6 | 15 | char commandsequence[2]; |
| go2dev | 0:f0cf55dd23f6 | 16 | |
| go2dev | 0:f0cf55dd23f6 | 17 | // Get range data from SRF02 in cm |
| go2dev | 0:f0cf55dd23f6 | 18 | // Send Tx burst command over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 19 | commandsequence[0] = 0x00; // Command register |
| go2dev | 0:f0cf55dd23f6 | 20 | commandsequence[1] = 0x51; // Ranging results in cm |
| go2dev | 0:f0cf55dd23f6 | 21 | m_i2c.write(m_addr, commandsequence, 2); // Request ranging from sensor |
| go2dev | 0:f0cf55dd23f6 | 22 | wait(0.07); // Average wait time for sonar pulse and processing |
| go2dev | 0:f0cf55dd23f6 | 23 | // Read back range over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 24 | commandsequence[0] = 0x02; // |
| go2dev | 0:f0cf55dd23f6 | 25 | m_i2c.write(m_addr, commandsequence, 1, 1); // |
| go2dev | 0:f0cf55dd23f6 | 26 | m_i2c.read(m_addr, commandsequence, 2); // Read two-byte echo result |
| go2dev | 0:f0cf55dd23f6 | 27 | //combine upper and lower bytes in to a single value |
| go2dev | 0:f0cf55dd23f6 | 28 | float range = ((commandsequence[0] << 8) + commandsequence[1]); |
| go2dev | 0:f0cf55dd23f6 | 29 | return range; |
| go2dev | 0:f0cf55dd23f6 | 30 | |
| go2dev | 0:f0cf55dd23f6 | 31 | } |
| go2dev | 0:f0cf55dd23f6 | 32 | |
| go2dev | 0:f0cf55dd23f6 | 33 | float SRF02::distancein(){ |
| go2dev | 0:f0cf55dd23f6 | 34 | //local variables |
| go2dev | 0:f0cf55dd23f6 | 35 | const char m_addr = 0xE0; //srf02 default slave address |
| go2dev | 0:f0cf55dd23f6 | 36 | char commandsequence[2]; |
| go2dev | 0:f0cf55dd23f6 | 37 | |
| go2dev | 0:f0cf55dd23f6 | 38 | // Get range data from SRF02 in cm |
| go2dev | 0:f0cf55dd23f6 | 39 | // Send Tx burst command over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 40 | commandsequence[0] = 0x00; // Command register |
| go2dev | 0:f0cf55dd23f6 | 41 | commandsequence[1] = 0x50; // Ranging results in cm |
| go2dev | 0:f0cf55dd23f6 | 42 | m_i2c.write(m_addr, commandsequence, 2); // Request ranging from sensor |
| go2dev | 0:f0cf55dd23f6 | 43 | wait(0.07); // Average wait time for sonar pulse and processing |
| go2dev | 0:f0cf55dd23f6 | 44 | // Read back range over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 45 | commandsequence[0] = 0x02; // |
| go2dev | 0:f0cf55dd23f6 | 46 | m_i2c.write(m_addr, commandsequence, 1, 1); // |
| go2dev | 0:f0cf55dd23f6 | 47 | m_i2c.read(m_addr, commandsequence, 2); // Read two-byte echo result |
| go2dev | 0:f0cf55dd23f6 | 48 | //combine upper and lower bytes in to a single value |
| go2dev | 0:f0cf55dd23f6 | 49 | float range = ((commandsequence[0] << 8) + commandsequence[1]); |
| go2dev | 0:f0cf55dd23f6 | 50 | return range; |
| go2dev | 0:f0cf55dd23f6 | 51 | |
| go2dev | 0:f0cf55dd23f6 | 52 | } |
| go2dev | 0:f0cf55dd23f6 | 53 | |
| go2dev | 0:f0cf55dd23f6 | 54 | float SRF02::distanceus(){ |
| go2dev | 0:f0cf55dd23f6 | 55 | //local variables |
| go2dev | 0:f0cf55dd23f6 | 56 | const char m_addr = 0xE0; //srf02 default slave address |
| go2dev | 0:f0cf55dd23f6 | 57 | char commandsequence[2]; |
| go2dev | 0:f0cf55dd23f6 | 58 | |
| go2dev | 0:f0cf55dd23f6 | 59 | // Get range data from SRF02 in cm |
| go2dev | 0:f0cf55dd23f6 | 60 | // Send Tx burst command over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 61 | commandsequence[0] = 0x00; // Command register |
| go2dev | 0:f0cf55dd23f6 | 62 | commandsequence[1] = 0x52; // Ranging results in cm |
| go2dev | 0:f0cf55dd23f6 | 63 | m_i2c.write(m_addr, commandsequence, 2); // Request ranging from sensor |
| go2dev | 0:f0cf55dd23f6 | 64 | wait(0.07); // Average wait time for sonar pulse and processing |
| go2dev | 0:f0cf55dd23f6 | 65 | // Read back range over I2C bus |
| go2dev | 0:f0cf55dd23f6 | 66 | commandsequence[0] = 0x02; // |
| go2dev | 0:f0cf55dd23f6 | 67 | m_i2c.write(m_addr, commandsequence, 1, 1); // |
| go2dev | 0:f0cf55dd23f6 | 68 | m_i2c.read(m_addr, commandsequence, 2); // Read two-byte echo result |
| go2dev | 0:f0cf55dd23f6 | 69 | //combine upper and lower bytes in to a single value |
| go2dev | 0:f0cf55dd23f6 | 70 | float range = ((commandsequence[0] << 8) + commandsequence[1]); |
| go2dev | 0:f0cf55dd23f6 | 71 | return range; |
| go2dev | 0:f0cf55dd23f6 | 72 | |
| go2dev | 0:f0cf55dd23f6 | 73 | } |
| go2dev | 0:f0cf55dd23f6 | 74 | |
| go2dev | 0:f0cf55dd23f6 | 75 | |
| go2dev | 0:f0cf55dd23f6 | 76 |