library for AMS ENS210 temperature and humidity sensor
Dependents: rIoTwear-temp-humid
AMS_ENS210.cpp
- Committer:
- UHSLMarcus
- Date:
- 2017-01-18
- Revision:
- 2:f5a7883ae9c2
- Parent:
- 1:94a79c88c105
- Child:
- 3:3b427231e5a7
File content as of revision 2:f5a7883ae9c2:
#include "AMS_ENS201.h" AMS_ENS210::AMS_ENS210(I2C * i2c) : _temp_mode(CONFIG_TEMP_OP_MODE), _humid_mode(CONFIG_HUMID_OP_MODE), _power_mode(CONFIG_POWER_MODE) { _i2c = i2c; } AMS_ENS210::AMS_ENS210(I2C * i2c, bool temp_single_shot, bool humid_single_shot) : _temp_mode(temp_single_shot), _humid_mode(humid_single_shot), _power_mode(CONFIG_POWER_MODE) { _i2c = i2c; } AMS_ENS210::AMS_ENS210(I2C * i2c, bool temp_single_shot, bool humid_single_shot, bool low_power) : _temp_mode(temp_single_shot), _humid_mode(humid_single_shot), _power_mode(low_power) { _i2c = i2c; } AMS_ENS210::AMS_ENS210() {} bool AMS_ENS210::init() { return write_config(); } bool AMS_ENS210::reset() { _reset = true; bool success = write_config(true, false); _reset = false; return success; } bool AMS_ENS210::power_mode(bool low_power) { _power_mode = low_power; write_config(true, false); } bool AMS_ENS210::power_mode() { return read_config(true, false)[0] & 1; // just mask bit 0 } bool AMS_ENS210::temp_mode(bool single_shot) { _temp_mode = single_shot; write_config(false, true); } bool AMS_ENS210::temp_mode() { return read_config(false, true)[0] & 1; // just mask bit 0 } bool AMS_ENS210::humid_mode(bool single_shot) { _humid_mode = single_shot; write_config(false, true); } bool AMS_ENS210::humid_mode() { return read_config(false, true)[0] & 0b10; // just mask bit 1 } void AMS_ENS210::i2c_interface(I2C * i2c) { _i2c = i2c; } bool AMS_ENS210::start(bool temp, bool humid) { char cmd[2] = {SENS_START, 0 | temp | (humid << 1)} return _i2c->write(SLAVE_ADDR, cmd, 2) == 2; } bool AMS_ENS210::stop(bool temp, bool humid) { char cmd[2] = {SENS_STOP, 0 | temp | (humid << 1)} return _i2c->write(SLAVE_ADDR, cmd, 2) == 2; } bool AMS_ENS210::temp_is_measuring() { char[1] output; i2c_read(SENS_STATUS, output, 1); return output[0] & 1; } bool AMS_ENS210::humid_is _measuring() { char[1] output; i2c_read(SENS_STATUS, output, 1); return output[0] >> 1 & 1; } bool AMS_ENS210::temp_has_data() { if (temp_mode()) { // when in single shot mode make sure sensor has started first if (!temp_is_measuring()) start(true, false); // set start bit if sensor is idle } char output[3]; i2c_read(SENS_TEMP, output, 3); // do crc7 // Store read data to avoid reading from I2C again temp_reading = 0 | output[0] | (output[1] << 8); // bytes 1 and 2 make the 16 bit data return output[3] & 1; // bit 0 of byte 3 is the valid flag } bool AMS_ENS210::humid_has_data() { if (humid_mode()) { // when in single shot mode make sure sensor has started first if (!humid_is_measuring()) start(false, true); // set start bit if sensor is idle } char output[3]; i2c_read(SENS_HUMID, output, 3); // do crc7 // Store read data to avoid reading from I2C again temp_reading = 0 | output[0] | (output[1] << 8); // bytes 1 and 2 make the 16 bit data return output[3] & 1; // bit 0 of byte 3 is the valid flag } uint16_t AMS_ENS210::temp_read() { uint16_t reading = 0; if (temp_mode()) { // when in single shot mode, data is read and saved in temp_has_data() reading = temp_reading; } else { char output[3]; i2c_read(SENS_TEMP, output, 3); // do crc7 if (output[2] & 1) // bit 0 of byte 3 is the valid flag reading = 0 | output[0] | (output[1] << 8); // bytes 1 and 2 make the 16 bit data } return reading; } uint16_t AMS_ENS210::humid_read() { uint16_t reading = 0; if (humid_mode()) { // when in single shot mode, data is read and saved in humid_has_data() reading = humid_reading; } else { char output[3]; i2c_read(SENS_HUMID, output, 3); // do crc7 if (output[2] & 1) // bit 0 of byte 3 is the valid flag reading = 0 | output[0] | (output[1] << 8); // bytes 1 and 2 make the 16 bit data } return reading; } /*** Private ***/ bool AMS_ENS210::write_config(bool system, bool sensor) { int w_bytes = 0; char cmd[2]; if (system) { cmd[0] = SYS_CONFIG; cmd[1] = 0 | _power_mode | _reset << 7; // bit 0 of SYS_CTRL is power mode, bit 7 is reset w_bytes += _i2c->write(SLAVE_ADDR, cmd, 2); } if (sensor) { cmd[0] = SENS_OP_MODE; cmd[1] = 0 | _temp_mode | (_humid_mode << 1); // bit 0 is temp mode, bit 1 is humid mode w_bytes += _i2c->write(SLAVE_ADDR, cmd, 2); } return w_bytes == (system + sensor)*2; // add error reporting/handling later... } const char *AMS_ENS210::read_config(bool system, bool sensor) { static char output[2]; if (system) i2c_read(SYS_CONFIG, output, 1); if (sensor) i2c_read(SYS_CONFIG, output+system, 1); return output; } int AMS_ENS210::i2c_read(char reg_addr, char* output, int len) { int read_count = 0; _i2c->start(); // send start condition for write if(_i2c->write(SLAVE_ADDR_W) == 1) { // write slave address if(_i2c->write(reg_addr) == 1) { // write register address _i2c->start(); // send another start condition for read for (int i = 0; < len) { // read len bytes output[i] = _i2c->read(i < len-1 ? 1 : 0); // ack all reads aside from the final one (i == len-1) read_count++; } } } _i2c->stop(); // send stop condition return read_count; }