BMP180
Fork of BMP180 by
BMP180.cpp@1:817fb4e66714, 2016-07-05 (annotated)
- Committer:
- brdarji
- Date:
- Tue Jul 05 07:09:02 2016 +0000
- Revision:
- 1:817fb4e66714
- Parent:
- 0:b2219e6e444b
BMP180 ;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
kgills |
0:b2219e6e444b | 1 | #include "BMP180.h" |
kgills |
0:b2219e6e444b | 2 | |
kgills |
0:b2219e6e444b | 3 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 4 | BMP180::BMP180(PinName sda, PinName scl) |
kgills |
0:b2219e6e444b | 5 | { |
kgills |
0:b2219e6e444b | 6 | i2c_ = new I2C(sda, scl); |
kgills |
0:b2219e6e444b | 7 | i2c_owner = true; |
kgills |
0:b2219e6e444b | 8 | |
kgills |
0:b2219e6e444b | 9 | i2c_->frequency(400000); |
kgills |
0:b2219e6e444b | 10 | } |
kgills |
0:b2219e6e444b | 11 | |
kgills |
0:b2219e6e444b | 12 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 13 | BMP180::BMP180(I2C *i2c) : |
kgills |
0:b2219e6e444b | 14 | i2c_(i2c) |
kgills |
0:b2219e6e444b | 15 | { |
kgills |
0:b2219e6e444b | 16 | i2c_owner = false; |
kgills |
0:b2219e6e444b | 17 | } |
kgills |
0:b2219e6e444b | 18 | |
kgills |
0:b2219e6e444b | 19 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 20 | BMP180::~BMP180() |
kgills |
0:b2219e6e444b | 21 | { |
kgills |
0:b2219e6e444b | 22 | if(i2c_owner) { |
kgills |
0:b2219e6e444b | 23 | delete i2c_; |
kgills |
0:b2219e6e444b | 24 | } |
kgills |
0:b2219e6e444b | 25 | } |
kgills |
0:b2219e6e444b | 26 | |
kgills |
0:b2219e6e444b | 27 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 28 | int BMP180::init(void) |
kgills |
0:b2219e6e444b | 29 | { |
kgills |
0:b2219e6e444b | 30 | char addr; |
kgills |
0:b2219e6e444b | 31 | char data[22]; |
kgills |
0:b2219e6e444b | 32 | int i; |
kgills |
0:b2219e6e444b | 33 | |
kgills |
0:b2219e6e444b | 34 | if (checkId() != 0) { |
brdarji | 1:817fb4e66714 | 35 | |
kgills |
0:b2219e6e444b | 36 | return -1; |
kgills |
0:b2219e6e444b | 37 | } |
kgills |
0:b2219e6e444b | 38 | |
kgills |
0:b2219e6e444b | 39 | addr = REG_ADDR_AC1; |
kgills |
0:b2219e6e444b | 40 | if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { |
kgills |
0:b2219e6e444b | 41 | return -1; |
kgills |
0:b2219e6e444b | 42 | } |
kgills |
0:b2219e6e444b | 43 | |
kgills |
0:b2219e6e444b | 44 | if (i2c_->read(I2C_ADDR, data, 22) != 0) { |
kgills |
0:b2219e6e444b | 45 | return -1; |
kgills |
0:b2219e6e444b | 46 | } |
kgills |
0:b2219e6e444b | 47 | |
kgills |
0:b2219e6e444b | 48 | for (i = 0; i < 11; i++) { |
kgills |
0:b2219e6e444b | 49 | calib.value[i] = (data[2*i] << 8) | data[(2*i)+1]; |
kgills |
0:b2219e6e444b | 50 | } |
kgills |
0:b2219e6e444b | 51 | |
kgills |
0:b2219e6e444b | 52 | return 0; |
kgills |
0:b2219e6e444b | 53 | } |
kgills |
0:b2219e6e444b | 54 | |
kgills |
0:b2219e6e444b | 55 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 56 | int BMP180::reset(void) |
kgills |
0:b2219e6e444b | 57 | { |
kgills |
0:b2219e6e444b | 58 | char data; |
kgills |
0:b2219e6e444b | 59 | |
kgills |
0:b2219e6e444b | 60 | data = REG_ADDR_RESET; |
kgills |
0:b2219e6e444b | 61 | if (i2c_->write(I2C_ADDR, &data, 1) != 0) { |
kgills |
0:b2219e6e444b | 62 | return -1; |
kgills |
0:b2219e6e444b | 63 | } |
kgills |
0:b2219e6e444b | 64 | |
kgills |
0:b2219e6e444b | 65 | data = 0xB6; |
kgills |
0:b2219e6e444b | 66 | if (i2c_->write(I2C_ADDR, &data, 1) != 0) { |
kgills |
0:b2219e6e444b | 67 | return -1; |
kgills |
0:b2219e6e444b | 68 | } |
kgills |
0:b2219e6e444b | 69 | |
kgills |
0:b2219e6e444b | 70 | return 0; |
kgills |
0:b2219e6e444b | 71 | } |
kgills |
0:b2219e6e444b | 72 | |
kgills |
0:b2219e6e444b | 73 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 74 | int BMP180::checkId(void) |
kgills |
0:b2219e6e444b | 75 | { |
kgills |
0:b2219e6e444b | 76 | char addr; |
kgills |
0:b2219e6e444b | 77 | char data; |
kgills |
0:b2219e6e444b | 78 | |
kgills |
0:b2219e6e444b | 79 | addr = REG_ADDR_ID; |
kgills |
0:b2219e6e444b | 80 | if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { |
kgills |
0:b2219e6e444b | 81 | return -1; |
kgills |
0:b2219e6e444b | 82 | } |
kgills |
0:b2219e6e444b | 83 | |
kgills |
0:b2219e6e444b | 84 | if (i2c_->read(I2C_ADDR, &data, 1) != 0) { |
kgills |
0:b2219e6e444b | 85 | return -1; |
kgills |
0:b2219e6e444b | 86 | } |
kgills |
0:b2219e6e444b | 87 | |
kgills |
0:b2219e6e444b | 88 | if (data != 0x55) { |
kgills |
0:b2219e6e444b | 89 | return -1; |
kgills |
0:b2219e6e444b | 90 | } |
kgills |
0:b2219e6e444b | 91 | |
kgills |
0:b2219e6e444b | 92 | return 0; |
kgills |
0:b2219e6e444b | 93 | } |
kgills |
0:b2219e6e444b | 94 | |
kgills |
0:b2219e6e444b | 95 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 96 | int BMP180::startPressure(BMP180::oversampling_t oss) |
kgills |
0:b2219e6e444b | 97 | { |
kgills |
0:b2219e6e444b | 98 | char data[2]; |
kgills |
0:b2219e6e444b | 99 | |
kgills |
0:b2219e6e444b | 100 | data[0] = REG_ADDR_CTRL; |
kgills |
0:b2219e6e444b | 101 | data[1] = CTRL_REG_PRESS_0 | ((oss & 0x3) << 6); |
kgills |
0:b2219e6e444b | 102 | oss_ = oss; |
kgills |
0:b2219e6e444b | 103 | |
kgills |
0:b2219e6e444b | 104 | if (i2c_->write(I2C_ADDR, data, 2) != 0) { |
kgills |
0:b2219e6e444b | 105 | return -1; |
kgills |
0:b2219e6e444b | 106 | } |
kgills |
0:b2219e6e444b | 107 | |
kgills |
0:b2219e6e444b | 108 | return 0; |
kgills |
0:b2219e6e444b | 109 | } |
kgills |
0:b2219e6e444b | 110 | |
kgills |
0:b2219e6e444b | 111 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 112 | int BMP180::getPressure(int *pressure) |
kgills |
0:b2219e6e444b | 113 | { |
kgills |
0:b2219e6e444b | 114 | char addr, byte[3]; |
kgills |
0:b2219e6e444b | 115 | uint32_t up; |
kgills |
0:b2219e6e444b | 116 | int32_t b6, x1, x2, x3, b3, p; |
kgills |
0:b2219e6e444b | 117 | uint32_t b4, b7; |
kgills |
0:b2219e6e444b | 118 | |
kgills |
0:b2219e6e444b | 119 | addr = REG_ADDR_DATA; |
kgills |
0:b2219e6e444b | 120 | if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { |
kgills |
0:b2219e6e444b | 121 | return -1; |
kgills |
0:b2219e6e444b | 122 | } |
kgills |
0:b2219e6e444b | 123 | |
kgills |
0:b2219e6e444b | 124 | if (i2c_->read(I2C_ADDR, byte, 3) != 0) { |
kgills |
0:b2219e6e444b | 125 | return -1; |
kgills |
0:b2219e6e444b | 126 | } |
kgills |
0:b2219e6e444b | 127 | |
kgills |
0:b2219e6e444b | 128 | up = ((byte[0] << 16) | (byte[1] << 8) | byte[2]) >> (8 - oss_); |
kgills |
0:b2219e6e444b | 129 | |
kgills |
0:b2219e6e444b | 130 | b6 = b5 - 4000; |
kgills |
0:b2219e6e444b | 131 | x1 = (b6 * b6) >> 12; |
kgills |
0:b2219e6e444b | 132 | x1 *= calib.b2; |
kgills |
0:b2219e6e444b | 133 | x1 >>= 11; |
kgills |
0:b2219e6e444b | 134 | x2 = calib.ac2 * b6; |
kgills |
0:b2219e6e444b | 135 | x2 >>= 11; |
kgills |
0:b2219e6e444b | 136 | x3 = x1 + x2; |
kgills |
0:b2219e6e444b | 137 | b3 = (((((int32_t)calib.ac1) * 4 + x3) << oss_) + 2); |
kgills |
0:b2219e6e444b | 138 | b3 >>= 2; |
kgills |
0:b2219e6e444b | 139 | |
kgills |
0:b2219e6e444b | 140 | x1 = (calib.ac3 * b6) >> 13; |
kgills |
0:b2219e6e444b | 141 | x2 = (calib.b1 * ((b6 * b6) >> 12)) >> 16; |
kgills |
0:b2219e6e444b | 142 | x3 = (x1 + x2 + 2) >> 2; |
kgills |
0:b2219e6e444b | 143 | b4 = (calib.ac4 * (uint32_t)(x3 + 32768)) >> 15; |
kgills |
0:b2219e6e444b | 144 | b7 = ((uint32_t)up - b3) * (50000 >> oss_); |
kgills |
0:b2219e6e444b | 145 | p = ((b7 < 0x80000000) ? ((b7 << 1) / b4) : ((b7 / b4) * 2)); |
kgills |
0:b2219e6e444b | 146 | x1 = p >> 8; |
kgills |
0:b2219e6e444b | 147 | x1 *= x1; |
kgills |
0:b2219e6e444b | 148 | x1 = (x1 * 3038) >> 16; |
kgills |
0:b2219e6e444b | 149 | x2 = (-7357 * p) >> 16; |
kgills |
0:b2219e6e444b | 150 | p += (x1 + x2 + 3791) >> 4; |
kgills |
0:b2219e6e444b | 151 | |
kgills |
0:b2219e6e444b | 152 | *pressure = p; |
kgills |
0:b2219e6e444b | 153 | |
kgills |
0:b2219e6e444b | 154 | return 0; |
kgills |
0:b2219e6e444b | 155 | } |
kgills |
0:b2219e6e444b | 156 | |
kgills |
0:b2219e6e444b | 157 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 158 | int BMP180::startTemperature(void) |
kgills |
0:b2219e6e444b | 159 | { |
kgills |
0:b2219e6e444b | 160 | char data[2] = { REG_ADDR_CTRL, CTRL_REG_TEMP }; |
kgills |
0:b2219e6e444b | 161 | |
kgills |
0:b2219e6e444b | 162 | if (i2c_->write(I2C_ADDR, data, 2) != 0) { |
kgills |
0:b2219e6e444b | 163 | return -1; |
kgills |
0:b2219e6e444b | 164 | } |
kgills |
0:b2219e6e444b | 165 | |
kgills |
0:b2219e6e444b | 166 | return 0; |
kgills |
0:b2219e6e444b | 167 | } |
kgills |
0:b2219e6e444b | 168 | |
kgills |
0:b2219e6e444b | 169 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 170 | int BMP180::getTemperature(float *tempC) |
kgills |
0:b2219e6e444b | 171 | { |
kgills |
0:b2219e6e444b | 172 | char addr, byte[2]; |
kgills |
0:b2219e6e444b | 173 | uint16_t ut; |
kgills |
0:b2219e6e444b | 174 | int32_t x1, x2; |
kgills |
0:b2219e6e444b | 175 | |
kgills |
0:b2219e6e444b | 176 | addr = REG_ADDR_DATA; |
kgills |
0:b2219e6e444b | 177 | if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { |
kgills |
0:b2219e6e444b | 178 | return -1; |
kgills |
0:b2219e6e444b | 179 | } |
kgills |
0:b2219e6e444b | 180 | |
kgills |
0:b2219e6e444b | 181 | if (i2c_->read(I2C_ADDR, byte, 2) != 0) { |
kgills |
0:b2219e6e444b | 182 | return -1; |
kgills |
0:b2219e6e444b | 183 | } |
kgills |
0:b2219e6e444b | 184 | |
kgills |
0:b2219e6e444b | 185 | ut = (byte[0] << 8) | byte[1]; |
kgills |
0:b2219e6e444b | 186 | |
kgills |
0:b2219e6e444b | 187 | x1 = ((ut - calib.ac6) * calib.ac5) >> 15; |
kgills |
0:b2219e6e444b | 188 | x2 = (calib.mc << 11) / (x1 + calib.md); |
kgills |
0:b2219e6e444b | 189 | b5 = x1 + x2; |
kgills |
0:b2219e6e444b | 190 | |
kgills |
0:b2219e6e444b | 191 | *tempC = (float)(b5 + 8) / 160; |
kgills |
0:b2219e6e444b | 192 | |
kgills |
0:b2219e6e444b | 193 | return 0; |
kgills |
0:b2219e6e444b | 194 | } |
kgills |
0:b2219e6e444b | 195 | |
kgills |
0:b2219e6e444b | 196 | //****************************************************************************** |
kgills |
0:b2219e6e444b | 197 | int BMP180::getTemperature(int16_t *tempCx10) |
kgills |
0:b2219e6e444b | 198 | { |
kgills |
0:b2219e6e444b | 199 | char addr, byte[2]; |
kgills |
0:b2219e6e444b | 200 | uint16_t ut; |
kgills |
0:b2219e6e444b | 201 | int32_t x1, x2; |
kgills |
0:b2219e6e444b | 202 | |
kgills |
0:b2219e6e444b | 203 | addr = REG_ADDR_DATA; |
kgills |
0:b2219e6e444b | 204 | if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { |
kgills |
0:b2219e6e444b | 205 | return -1; |
kgills |
0:b2219e6e444b | 206 | } |
kgills |
0:b2219e6e444b | 207 | |
kgills |
0:b2219e6e444b | 208 | if (i2c_->read(I2C_ADDR, byte, 2) != 0) { |
kgills |
0:b2219e6e444b | 209 | return -1; |
kgills |
0:b2219e6e444b | 210 | } |
kgills |
0:b2219e6e444b | 211 | |
kgills |
0:b2219e6e444b | 212 | ut = (byte[0] << 8) | byte[1]; |
kgills |
0:b2219e6e444b | 213 | |
kgills |
0:b2219e6e444b | 214 | x1 = ((ut - calib.ac6) * calib.ac5) >> 15; |
kgills |
0:b2219e6e444b | 215 | x2 = (calib.mc << 11) / (x1 + calib.md); |
kgills |
0:b2219e6e444b | 216 | b5 = x1 + x2; |
kgills |
0:b2219e6e444b | 217 | |
kgills |
0:b2219e6e444b | 218 | *tempCx10 = (b5 + 8) >> 4; |
kgills |
0:b2219e6e444b | 219 | |
kgills |
0:b2219e6e444b | 220 | return 0; |
kgills |
0:b2219e6e444b | 221 | } |