Jens Schmidt / MicrobitIAQ

uses BBC micro:bit to measure and display indoor air quality using Bosch BME680 and/or Sensirion SGP30

Dependencies:   microbit

uses Bosch BME680 and/or Sensirion SGP30 sensors to measure indor air quality

sensors should be connected to BBC micro:bit using i2c

commands are received and data is being sent using uBit / nordic radio protocol

display ---

last line always indicates: - first dot: bme680 detected - second dot: sgp30 detected - third dot: sgp 30 setting humidity/temperature - fourth dor: sgp30 measuring - fith dot: bme680 measuring

the detect dots should be in a stable state (not blinking) the measuring dots should be blinking (constant light means: measurement failed)

if only one bme680 is present: - first 3 lines indicate gas resistence (air quality / more dots == worse quality) - fourth line indicates humidity level

if only sgp30 is present: - first two lines indicate SGP30 VOC level - third and fourth line indicate sgp30 CO2 level

if both sensors are present: - first line indicates SGP30 VOC level - second line line indicates sgp30 CO2 level - third line indicates bme680 gas resistence (air quality) - fourth line indicates bme 680 humidity level

buttons - B display state, switches betweeen - full bright - low light - display off

AB reset sgp30 baseline in non volatile storage

data logging -- during measurements the minimum and mximum values for each measured value (temperature, air pressure, humidity,gas resistance, VOC, CO2) are being stored in non volatile storage those (and the last measurement results) are being shown when btn A has been pressed

i2c/i2c_callbacks.cpp@0:cef60cc92da0, 2018-12-03 (annotated)

Committer:
jsa1969
Date:
Mon Dec 03 13:19:07 2018 +0000
Revision:
0:cef60cc92da0
Child:
2:544117df8c65
initial bme680

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jsa1969 0:cef60cc92da0 1 #include "i2c_callbacks.h"
jsa1969 0:cef60cc92da0 2
jsa1969 0:cef60cc92da0 3 I2cCallbacks::I2cCallbacks(MicroBit* uBit){
jsa1969 0:cef60cc92da0 4 _uBit = uBit;
jsa1969 0:cef60cc92da0 5 }
jsa1969 0:cef60cc92da0 6
jsa1969 0:cef60cc92da0 7 int I2cCallbacks::read(uint8_t address, uint8_t reg, uint8_t *buffer, uint16_t length){
jsa1969 0:cef60cc92da0 8 int result;
jsa1969 0:cef60cc92da0 9
jsa1969 0:cef60cc92da0 10 if (buffer == NULL || length <= 0)
jsa1969 0:cef60cc92da0 11 return MICROBIT_INVALID_PARAMETER;
jsa1969 0:cef60cc92da0 12
jsa1969 0:cef60cc92da0 13 result = _uBit->i2c.write(address, (const char *)&reg, 1, true);
jsa1969 0:cef60cc92da0 14 if (result !=0)
jsa1969 0:cef60cc92da0 15 return MICROBIT_I2C_ERROR;
jsa1969 0:cef60cc92da0 16
jsa1969 0:cef60cc92da0 17 result = _uBit->i2c.read(address, (char *)buffer, length);
jsa1969 0:cef60cc92da0 18 if (result !=0)
jsa1969 0:cef60cc92da0 19 return MICROBIT_I2C_ERROR;
jsa1969 0:cef60cc92da0 20
jsa1969 0:cef60cc92da0 21 return MICROBIT_OK;
jsa1969 0:cef60cc92da0 22 }
jsa1969 0:cef60cc92da0 23
jsa1969 0:cef60cc92da0 24 int I2cCallbacks::write(uint8_t dev_id, uint8_t reg_addr, uint8_t *data, uint16_t length){
jsa1969 0:cef60cc92da0 25 char* tmpBuf = new char[length+1];
jsa1969 0:cef60cc92da0 26 tmpBuf[0] = reg_addr;
jsa1969 0:cef60cc92da0 27 for (int i=0,j=1; i <length ; ++i,++j){
jsa1969 0:cef60cc92da0 28 tmpBuf[j] = data[i];
jsa1969 0:cef60cc92da0 29 }
jsa1969 0:cef60cc92da0 30
jsa1969 0:cef60cc92da0 31 return _uBit->i2c.write(dev_id, tmpBuf, length+1);
jsa1969 0:cef60cc92da0 32 }
jsa1969 0:cef60cc92da0 33
jsa1969 0:cef60cc92da0 34 void I2cCallbacks::delay_ms(uint32_t period) {
jsa1969 0:cef60cc92da0 35 _uBit->sleep(period);
jsa1969 0:cef60cc92da0 36 }