[232] | 1 | #include <LSM303.h>
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| 2 | #include <Wire.h>
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| 3 | #include <math.h>
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| 4 |
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| 5 | // Defines ////////////////////////////////////////////////////////////////
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| 6 |
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| 7 | // The Arduino two-wire interface uses a 7-bit number for the address,
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| 8 | // and sets the last bit correctly based on reads and writes
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| 9 | #define D_SA0_HIGH_ADDRESS 0b0011101
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| 10 | #define D_SA0_LOW_ADDRESS 0b0011110
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| 11 | #define DLHC_DLM_DLH_MAG_ADDRESS 0b0011110
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| 12 | #define DLHC_DLM_DLH_ACC_SA0_HIGH_ADDRESS 0b0011001
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| 13 | #define DLM_DLH_ACC_SA0_LOW_ADDRESS 0b0011000
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| 14 |
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| 15 | #define TEST_REG_ERROR -1
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| 16 |
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| 17 | #define D_WHO_ID 0x49
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| 18 | #define DLM_WHO_ID 0x3C
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| 19 |
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| 20 | // Constructors ////////////////////////////////////////////////////////////////
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| 21 |
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| 22 | LSM303::LSM303(void)
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| 23 | {
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| 24 | /*
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| 25 | These values lead to an assumed magnetometer bias of 0.
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| 26 | Use the Calibrate example program to determine appropriate values
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| 27 | for your particular unit. The Heading example demonstrates how to
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| 28 | adjust these values in your own sketch.
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| 29 | */
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| 30 | m_min = (LSM303::vector<int16_t>){-32767, -32767, -32767};
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| 31 | m_max = (LSM303::vector<int16_t>){+32767, +32767, +32767};
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| 32 |
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| 33 | _device = device_auto;
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| 34 |
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| 35 | io_timeout = 0; // 0 = no timeout
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| 36 | did_timeout = false;
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| 37 | }
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| 38 |
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| 39 | // Public Methods //////////////////////////////////////////////////////////////
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| 40 |
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| 41 | // Did a timeout occur in readAcc(), readMag(), or read() since the last call to timeoutOccurred()?
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| 42 | bool LSM303::timeoutOccurred()
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| 43 | {
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| 44 | bool tmp = did_timeout;
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| 45 | did_timeout = false;
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| 46 | return tmp;
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| 47 | }
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| 48 |
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| 49 | void LSM303::setTimeout(unsigned int timeout)
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| 50 | {
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| 51 | io_timeout = timeout;
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| 52 | }
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| 53 |
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| 54 | unsigned int LSM303::getTimeout()
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| 55 | {
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| 56 | return io_timeout;
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| 57 | }
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| 58 |
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| 59 | bool LSM303::init(deviceType device, sa0State sa0)
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| 60 | {
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| 61 | // perform auto-detection unless device type and SA0 state were both specified
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| 62 | if (device == device_auto || sa0 == sa0_auto)
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| 63 | {
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| 64 | // check for LSM303D if device is unidentified or was specified to be this type
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| 65 | if (device == device_auto || device == device_D)
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| 66 | {
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| 67 | // check SA0 high address unless SA0 was specified to be low
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| 68 | if (sa0 != sa0_low && testReg(D_SA0_HIGH_ADDRESS, WHO_AM_I) == D_WHO_ID)
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| 69 | {
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| 70 | // device responds to address 0011101 with D ID; it's a D with SA0 high
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| 71 | device = device_D;
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| 72 | sa0 = sa0_high;
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| 73 | }
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| 74 | // check SA0 low address unless SA0 was specified to be high
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| 75 | else if (sa0 != sa0_high && testReg(D_SA0_LOW_ADDRESS, WHO_AM_I) == D_WHO_ID)
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| 76 | {
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| 77 | // device responds to address 0011110 with D ID; it's a D with SA0 low
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| 78 | device = device_D;
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| 79 | sa0 = sa0_low;
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| 80 | }
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| 81 | }
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| 82 |
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| 83 | // check for LSM303DLHC, DLM, DLH if device is still unidentified or was specified to be one of these types
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| 84 | if (device == device_auto || device == device_DLHC || device == device_DLM || device == device_DLH)
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| 85 | {
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| 86 | // check SA0 high address unless SA0 was specified to be low
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| 87 | if (sa0 != sa0_low && testReg(DLHC_DLM_DLH_ACC_SA0_HIGH_ADDRESS, CTRL_REG1_A) != TEST_REG_ERROR)
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| 88 | {
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| 89 | // device responds to address 0011001; it's a DLHC, DLM with SA0 high, or DLH with SA0 high
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| 90 | sa0 = sa0_high;
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| 91 | if (device == device_auto)
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| 92 | {
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| 93 | // use magnetometer WHO_AM_I register to determine device type
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| 94 | //
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| 95 | // DLHC seems to respond to WHO_AM_I request the same way as DLM, even though this
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| 96 | // register isn't documented in its datasheet. Since the DLHC accelerometer address is the
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| 97 | // same as the DLM with SA0 high, but Pololu DLM boards pull SA0 low by default, we'll
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| 98 | // guess that a device whose accelerometer responds to the SA0 high address and whose
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| 99 | // magnetometer gives the DLM ID is actually a DLHC.
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| 100 | device = (testReg(DLHC_DLM_DLH_MAG_ADDRESS, WHO_AM_I_M) == DLM_WHO_ID) ? device_DLHC : device_DLH;
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| 101 | }
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| 102 | }
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| 103 | // check SA0 low address unless SA0 was specified to be high
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| 104 | else if (sa0 != sa0_high && testReg(DLM_DLH_ACC_SA0_LOW_ADDRESS, CTRL_REG1_A) != TEST_REG_ERROR)
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| 105 | {
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| 106 | // device responds to address 0011000; it's a DLM with SA0 low or DLH with SA0 low
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| 107 | sa0 = sa0_low;
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| 108 | if (device == device_auto)
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| 109 | {
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| 110 | // use magnetometer WHO_AM_I register to determine device type
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| 111 | device = (testReg(DLHC_DLM_DLH_MAG_ADDRESS, WHO_AM_I_M) == DLM_WHO_ID) ? device_DLM : device_DLH;
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| 112 | }
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| 113 | }
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| 114 | }
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| 115 |
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| 116 | // make sure device and SA0 were successfully detected; otherwise, indicate failure
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| 117 | if (device == device_auto || sa0 == sa0_auto)
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| 118 | {
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| 119 | return false;
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| 120 | }
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| 121 | }
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| 122 |
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| 123 | _device = device;
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| 124 |
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| 125 | // set device addresses and translated register addresses
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| 126 | switch (device)
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| 127 | {
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| 128 | case device_D:
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| 129 | acc_address = mag_address = (sa0 == sa0_high) ? D_SA0_HIGH_ADDRESS : D_SA0_LOW_ADDRESS;
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| 130 | translated_regs[-OUT_X_L_M] = D_OUT_X_L_M;
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| 131 | translated_regs[-OUT_X_H_M] = D_OUT_X_H_M;
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| 132 | translated_regs[-OUT_Y_L_M] = D_OUT_Y_L_M;
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| 133 | translated_regs[-OUT_Y_H_M] = D_OUT_Y_H_M;
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| 134 | translated_regs[-OUT_Z_L_M] = D_OUT_Z_L_M;
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| 135 | translated_regs[-OUT_Z_H_M] = D_OUT_Z_H_M;
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| 136 | break;
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| 137 |
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| 138 | case device_DLHC:
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| 139 | acc_address = DLHC_DLM_DLH_ACC_SA0_HIGH_ADDRESS; // DLHC doesn't have configurable SA0 but uses same acc address as DLM/DLH with SA0 high
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| 140 | mag_address = DLHC_DLM_DLH_MAG_ADDRESS;
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| 141 | translated_regs[-OUT_X_H_M] = DLHC_OUT_X_H_M;
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| 142 | translated_regs[-OUT_X_L_M] = DLHC_OUT_X_L_M;
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| 143 | translated_regs[-OUT_Y_H_M] = DLHC_OUT_Y_H_M;
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| 144 | translated_regs[-OUT_Y_L_M] = DLHC_OUT_Y_L_M;
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| 145 | translated_regs[-OUT_Z_H_M] = DLHC_OUT_Z_H_M;
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| 146 | translated_regs[-OUT_Z_L_M] = DLHC_OUT_Z_L_M;
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| 147 | break;
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| 148 |
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| 149 | case device_DLM:
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| 150 | acc_address = (sa0 == sa0_high) ? DLHC_DLM_DLH_ACC_SA0_HIGH_ADDRESS : DLM_DLH_ACC_SA0_LOW_ADDRESS;
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| 151 | mag_address = DLHC_DLM_DLH_MAG_ADDRESS;
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| 152 | translated_regs[-OUT_X_H_M] = DLM_OUT_X_H_M;
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| 153 | translated_regs[-OUT_X_L_M] = DLM_OUT_X_L_M;
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| 154 | translated_regs[-OUT_Y_H_M] = DLM_OUT_Y_H_M;
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| 155 | translated_regs[-OUT_Y_L_M] = DLM_OUT_Y_L_M;
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| 156 | translated_regs[-OUT_Z_H_M] = DLM_OUT_Z_H_M;
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| 157 | translated_regs[-OUT_Z_L_M] = DLM_OUT_Z_L_M;
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| 158 | break;
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| 159 |
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| 160 | case device_DLH:
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| 161 | acc_address = (sa0 == sa0_high) ? DLHC_DLM_DLH_ACC_SA0_HIGH_ADDRESS : DLM_DLH_ACC_SA0_LOW_ADDRESS;
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| 162 | mag_address = DLHC_DLM_DLH_MAG_ADDRESS;
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| 163 | translated_regs[-OUT_X_H_M] = DLH_OUT_X_H_M;
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| 164 | translated_regs[-OUT_X_L_M] = DLH_OUT_X_L_M;
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| 165 | translated_regs[-OUT_Y_H_M] = DLH_OUT_Y_H_M;
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| 166 | translated_regs[-OUT_Y_L_M] = DLH_OUT_Y_L_M;
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| 167 | translated_regs[-OUT_Z_H_M] = DLH_OUT_Z_H_M;
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| 168 | translated_regs[-OUT_Z_L_M] = DLH_OUT_Z_L_M;
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| 169 | break;
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| 170 | }
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| 171 |
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| 172 | return true;
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| 173 | }
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| 174 |
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| 175 | /*
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| 176 | Enables the LSM303's accelerometer and magnetometer. Also:
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| 177 | - Sets sensor full scales (gain) to default power-on values, which are
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| 178 | +/- 2 g for accelerometer and +/- 1.3 gauss for magnetometer
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| 179 | (+/- 4 gauss on LSM303D).
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| 180 | - Selects 50 Hz ODR (output data rate) for accelerometer and 7.5 Hz
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| 181 | ODR for magnetometer (6.25 Hz on LSM303D). (These are the ODR
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| 182 | settings for which the electrical characteristics are specified in
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| 183 | the datasheets.)
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| 184 | - Enables high resolution modes (if available).
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| 185 | Note that this function will also reset other settings controlled by
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| 186 | the registers it writes to.
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| 187 | */
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| 188 | void LSM303::enableDefault(void)
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| 189 | {
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| 190 |
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| 191 | if (_device == device_D)
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| 192 | {
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| 193 | // Accelerometer
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| 194 |
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| 195 | // 0x00 = 0b00000000
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| 196 | // AFS = 0 (+/- 2 g full scale)
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| 197 | writeReg(CTRL2, 0x00);
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| 198 |
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| 199 | // 0x57 = 0b01010111
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| 200 | // AODR = 0101 (50 Hz ODR); AZEN = AYEN = AXEN = 1 (all axes enabled)
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| 201 | writeReg(CTRL1, 0x57);
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| 202 |
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| 203 | // Magnetometer
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| 204 |
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| 205 | // 0x64 = 0b01100100
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| 206 | // M_RES = 11 (high resolution mode); M_ODR = 001 (6.25 Hz ODR)
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| 207 | writeReg(CTRL5, 0x64);
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| 208 |
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| 209 | // 0x20 = 0b00100000
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| 210 | // MFS = 01 (+/- 4 gauss full scale)
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| 211 | writeReg(CTRL6, 0x20);
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| 212 |
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| 213 | // 0x00 = 0b00000000
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| 214 | // MLP = 0 (low power mode off); MD = 00 (continuous-conversion mode)
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| 215 | writeReg(CTRL7, 0x00);
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| 216 | }
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| 217 | else
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| 218 | {
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| 219 | // Accelerometer
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| 220 |
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| 221 | if (_device == device_DLHC)
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| 222 | {
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| 223 | // 0x08 = 0b00001000
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| 224 | // FS = 00 (+/- 2 g full scale); HR = 1 (high resolution enable)
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| 225 | writeAccReg(CTRL_REG4_A, 0x08);
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| 226 |
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| 227 | // 0x47 = 0b01000111
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| 228 | // ODR = 0100 (50 Hz ODR); LPen = 0 (normal mode); Zen = Yen = Xen = 1 (all axes enabled)
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| 229 | writeAccReg(CTRL_REG1_A, 0x47);
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| 230 | }
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| 231 | else // DLM, DLH
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| 232 | {
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| 233 | // 0x00 = 0b00000000
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| 234 | // FS = 00 (+/- 2 g full scale)
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| 235 | writeAccReg(CTRL_REG4_A, 0x00);
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| 236 |
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| 237 | // 0x27 = 0b00100111
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| 238 | // PM = 001 (normal mode); DR = 00 (50 Hz ODR); Zen = Yen = Xen = 1 (all axes enabled)
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| 239 | writeAccReg(CTRL_REG1_A, 0x27);
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| 240 | }
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| 241 |
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| 242 | // Magnetometer
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| 243 |
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| 244 | // 0x0C = 0b00001100
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| 245 | // DO = 011 (7.5 Hz ODR)
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| 246 | writeMagReg(CRA_REG_M, 0x0C);
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| 247 |
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| 248 | // 0x20 = 0b00100000
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| 249 | // GN = 001 (+/- 1.3 gauss full scale)
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| 250 | writeMagReg(CRB_REG_M, 0x20);
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| 251 |
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| 252 | // 0x00 = 0b00000000
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| 253 | // MD = 00 (continuous-conversion mode)
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| 254 | writeMagReg(MR_REG_M, 0x00);
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| 255 | }
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| 256 | }
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| 257 |
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| 258 | // Writes an accelerometer register
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| 259 | void LSM303::writeAccReg(byte reg, byte value)
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| 260 | {
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| 261 | Wire.beginTransmission(acc_address);
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| 262 | Wire.write(reg);
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| 263 | Wire.write(value);
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| 264 | last_status = Wire.endTransmission();
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| 265 | }
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| 266 |
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| 267 | // Reads an accelerometer register
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| 268 | byte LSM303::readAccReg(byte reg)
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| 269 | {
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| 270 | byte value;
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| 271 |
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| 272 | Wire.beginTransmission(acc_address);
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| 273 | Wire.write(reg);
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| 274 | last_status = Wire.endTransmission();
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| 275 | Wire.requestFrom(acc_address, (byte)1);
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| 276 | value = Wire.read();
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| 277 | Wire.endTransmission();
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| 278 |
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| 279 | return value;
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| 280 | }
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| 281 |
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| 282 | // Writes a magnetometer register
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| 283 | void LSM303::writeMagReg(byte reg, byte value)
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| 284 | {
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| 285 | Wire.beginTransmission(mag_address);
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| 286 | Wire.write(reg);
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| 287 | Wire.write(value);
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| 288 | last_status = Wire.endTransmission();
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| 289 | }
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| 290 |
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| 291 | // Reads a magnetometer register
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| 292 | byte LSM303::readMagReg(int reg)
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| 293 | {
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| 294 | byte value;
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| 295 |
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| 296 | // if dummy register address (magnetometer Y/Z), look up actual translated address (based on device type)
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| 297 | if (reg < 0)
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| 298 | {
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| 299 | reg = translated_regs[-reg];
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| 300 | }
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| 301 |
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| 302 | Wire.beginTransmission(mag_address);
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| 303 | Wire.write(reg);
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| 304 | last_status = Wire.endTransmission();
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| 305 | Wire.requestFrom(mag_address, (byte)1);
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| 306 | value = Wire.read();
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| 307 | Wire.endTransmission();
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| 308 |
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| 309 | return value;
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| 310 | }
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| 311 |
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| 312 | void LSM303::writeReg(byte reg, byte value)
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| 313 | {
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| 314 | // mag address == acc_address for LSM303D, so it doesn't really matter which one we use.
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| 315 | if (_device == device_D || reg < CTRL_REG1_A)
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| 316 | {
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| 317 | writeMagReg(reg, value);
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| 318 | }
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| 319 | else
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| 320 | {
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| 321 | writeAccReg(reg, value);
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| 322 | }
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| 323 | }
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| 324 |
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| 325 | // Note that this function will not work for reading TEMP_OUT_H_M and TEMP_OUT_L_M on the DLHC.
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| 326 | // To read those two registers, use readMagReg() instead.
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| 327 | byte LSM303::readReg(int reg)
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| 328 | {
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| 329 | // mag address == acc_address for LSM303D, so it doesn't really matter which one we use.
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| 330 | // Use readMagReg so it can translate OUT_[XYZ]_[HL]_M
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| 331 | if (_device == device_D || reg < CTRL_REG1_A)
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| 332 | {
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| 333 | return readMagReg(reg);
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| 334 | }
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| 335 | else
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| 336 | {
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| 337 | return readAccReg(reg);
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| 338 | }
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| 339 | }
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| 340 |
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| 341 | // Reads the 3 accelerometer channels and stores them in vector a
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| 342 | void LSM303::readAcc(void)
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| 343 | {
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| 344 | Wire.beginTransmission(acc_address);
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| 345 | // assert the MSB of the address to get the accelerometer
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| 346 | // to do slave-transmit subaddress updating.
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| 347 | Wire.write(OUT_X_L_A | (1 << 7));
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| 348 | last_status = Wire.endTransmission();
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| 349 | Wire.requestFrom(acc_address, (byte)6);
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| 350 |
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| 351 | unsigned int millis_start = millis();
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| 352 | while (Wire.available() < 6) {
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| 353 | if (io_timeout > 0 && ((unsigned int)millis() - millis_start) > io_timeout)
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| 354 | {
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| 355 | did_timeout = true;
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| 356 | return;
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| 357 | }
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| 358 | }
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| 359 |
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| 360 | byte xla = Wire.read();
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| 361 | byte xha = Wire.read();
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| 362 | byte yla = Wire.read();
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| 363 | byte yha = Wire.read();
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| 364 | byte zla = Wire.read();
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| 365 | byte zha = Wire.read();
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| 366 |
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| 367 | // combine high and low bytes
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| 368 | // This no longer drops the lowest 4 bits of the readings from the DLH/DLM/DLHC, which are always 0
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| 369 | // (12-bit resolution, left-aligned). The D has 16-bit resolution
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| 370 | a.x = (int16_t)(xha << 8 | xla);
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| 371 | a.y = (int16_t)(yha << 8 | yla);
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| 372 | a.z = (int16_t)(zha << 8 | zla);
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| 373 | }
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| 374 |
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| 375 | // Reads the 3 magnetometer channels and stores them in vector m
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| 376 | void LSM303::readMag(void)
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| 377 | {
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| 378 | Wire.beginTransmission(mag_address);
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| 379 | // If LSM303D, assert MSB to enable subaddress updating
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| 380 | // OUT_X_L_M comes first on D, OUT_X_H_M on others
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| 381 | Wire.write((_device == device_D) ? translated_regs[-OUT_X_L_M] | (1 << 7) : translated_regs[-OUT_X_H_M]);
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| 382 | last_status = Wire.endTransmission();
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| 383 | Wire.requestFrom(mag_address, (byte)6);
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| 384 |
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| 385 | unsigned int millis_start = millis();
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| 386 | while (Wire.available() < 6) {
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| 387 | if (io_timeout > 0 && ((unsigned int)millis() - millis_start) > io_timeout)
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| 388 | {
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| 389 | did_timeout = true;
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| 390 | return;
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| 391 | }
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| 392 | }
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| 393 |
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| 394 | byte xlm, xhm, ylm, yhm, zlm, zhm;
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| 395 |
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| 396 | if (_device == device_D)
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| 397 | {
|
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| 398 | // D: X_L, X_H, Y_L, Y_H, Z_L, Z_H
|
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| 399 | xlm = Wire.read();
|
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| 400 | xhm = Wire.read();
|
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| 401 | ylm = Wire.read();
|
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| 402 | yhm = Wire.read();
|
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| 403 | zlm = Wire.read();
|
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| 404 | zhm = Wire.read();
|
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| 405 | }
|
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| 406 | else
|
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| 407 | {
|
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| 408 | // DLHC, DLM, DLH: X_H, X_L...
|
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| 409 | xhm = Wire.read();
|
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| 410 | xlm = Wire.read();
|
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| 411 |
|
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| 412 | if (_device == device_DLH)
|
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| 413 | {
|
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| 414 | // DLH: ...Y_H, Y_L, Z_H, Z_L
|
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| 415 | yhm = Wire.read();
|
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| 416 | ylm = Wire.read();
|
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| 417 | zhm = Wire.read();
|
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| 418 | zlm = Wire.read();
|
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| 419 | }
|
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| 420 | else
|
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| 421 | {
|
---|
| 422 | // DLM, DLHC: ...Z_H, Z_L, Y_H, Y_L
|
---|
| 423 | zhm = Wire.read();
|
---|
| 424 | zlm = Wire.read();
|
---|
| 425 | yhm = Wire.read();
|
---|
| 426 | ylm = Wire.read();
|
---|
| 427 | }
|
---|
| 428 | }
|
---|
| 429 |
|
---|
| 430 | // combine high and low bytes
|
---|
| 431 | m.x = (int16_t)(xhm << 8 | xlm);
|
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| 432 | m.y = (int16_t)(yhm << 8 | ylm);
|
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| 433 | m.z = (int16_t)(zhm << 8 | zlm);
|
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| 434 | }
|
---|
| 435 |
|
---|
| 436 | // Reads all 6 channels of the LSM303 and stores them in the object variables
|
---|
| 437 | void LSM303::read(void)
|
---|
| 438 | {
|
---|
| 439 | readAcc();
|
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| 440 | readMag();
|
---|
| 441 | }
|
---|
| 442 |
|
---|
| 443 | /*
|
---|
| 444 | Returns the angular difference in the horizontal plane between a
|
---|
| 445 | default vector and north, in degrees.
|
---|
| 446 |
|
---|
| 447 | The default vector here is chosen to point along the surface of the
|
---|
| 448 | PCB, in the direction of the top of the text on the silkscreen.
|
---|
| 449 | This is the +X axis on the Pololu LSM303D carrier and the -Y axis on
|
---|
| 450 | the Pololu LSM303DLHC, LSM303DLM, and LSM303DLH carriers.
|
---|
| 451 | */
|
---|
| 452 | float LSM303::heading(void)
|
---|
| 453 | {
|
---|
| 454 | if (_device == device_D)
|
---|
| 455 | {
|
---|
| 456 | return heading((vector<int>){1, 0, 0});
|
---|
| 457 | }
|
---|
| 458 | else
|
---|
| 459 | {
|
---|
| 460 | return heading((vector<int>){0, -1, 0});
|
---|
| 461 | }
|
---|
| 462 | }
|
---|
| 463 |
|
---|
| 464 | void LSM303::vector_normalize(vector<float> *a)
|
---|
| 465 | {
|
---|
| 466 | float mag = sqrt(vector_dot(a, a));
|
---|
| 467 | a->x /= mag;
|
---|
| 468 | a->y /= mag;
|
---|
| 469 | a->z /= mag;
|
---|
| 470 | }
|
---|
| 471 |
|
---|
| 472 | // Private Methods //////////////////////////////////////////////////////////////
|
---|
| 473 |
|
---|
| 474 | int LSM303::testReg(byte address, regAddr reg)
|
---|
| 475 | {
|
---|
| 476 | Wire.beginTransmission(address);
|
---|
| 477 | Wire.write((byte)reg);
|
---|
| 478 | if (Wire.endTransmission() != 0)
|
---|
| 479 | {
|
---|
| 480 | return TEST_REG_ERROR;
|
---|
| 481 | }
|
---|
| 482 |
|
---|
| 483 | Wire.requestFrom(address, (byte)1);
|
---|
| 484 | if (Wire.available())
|
---|
| 485 | {
|
---|
| 486 | return Wire.read();
|
---|
| 487 | }
|
---|
| 488 | else
|
---|
| 489 | {
|
---|
| 490 | return TEST_REG_ERROR;
|
---|
| 491 | }
|
---|
| 492 | }
|
---|