| 217 | |
| 218 | |
| 219 | bool SGP30::readRaw() |
| 220 | { |
| 221 | if (_lastRequest == 0) return false; |
| 222 | if (millis() - _lastRequest < 26) return false; // Page 11 |
| 223 | _lastRequest = 0; |
| 224 | |
| 225 | if (_wire->requestFrom(_address, (uint8_t)6) != 6) |
| 226 | { |
| 227 | _error = SGP30_ERROR_I2C; |
| 228 | return false; |
| 229 | } |
| 230 | _h2 = _wire->read() << 8; |
| 231 | _h2 += _wire->read(); |
| 232 | uint8_t crc = _wire->read(); |
| 233 | if (_CRC8(_h2) != crc) |
| 234 | { |
| 235 | _error = SGP30_ERROR_CRC; |
| 236 | return false; |
| 237 | } |
| 238 | _ethanol = _wire->read() << 8; |
| 239 | _ethanol += _wire->read(); |
| 240 | crc = _wire->read(); |
| 241 | if (_CRC8(_ethanol) != crc) |
| 242 | { |
| 243 | _error = SGP30_ERROR_CRC; |
| 244 | return false; |
| 245 | } |
| 246 | _error = SGP30_OK; |
| 247 | return true; |
| 248 | } |
| 249 | |
| 250 | |
| 251 | // experimental - datasheet Page 2 |