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@43:f968ca84d4ed, 2019-02-13 (annotated)

Committer:
jsa1969
Date:
Wed Feb 13 18:18:25 2019 +0000
Revision:
43:f968ca84d4ed
Parent:
42:ce269f988ac8
Child:
44:67a19da5f269
seems the stray values resulting from delay problems have finally been solved

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jsa1969 0:cef60cc92da0 1 #include "i2c_callbacks.h"
jsa1969 0:cef60cc92da0 2
jsa1969 40:a67a880cb538 3 I2cCallbacks::I2cCallbacks(MicroBit* uBit, MicroBitI2C* i2c){
jsa1969 0:cef60cc92da0 4 _uBit = uBit;
jsa1969 42:ce269f988ac8 5 _locked = false;
jsa1969 40:a67a880cb538 6 if (i2c == NULL) {
jsa1969 40:a67a880cb538 7 _i2c = &(_uBit->i2c);
jsa1969 40:a67a880cb538 8 }
jsa1969 40:a67a880cb538 9 else {
jsa1969 40:a67a880cb538 10 _i2c = i2c;
jsa1969 40:a67a880cb538 11 }
jsa1969 0:cef60cc92da0 12 }
jsa1969 0:cef60cc92da0 13
jsa1969 15:8bb5c580d453 14 int I2cCallbacks::read(const uint8_t address, const uint8_t reg, uint8_t *buffer, const uint16_t length){
jsa1969 0:cef60cc92da0 15 int result;
jsa1969 0:cef60cc92da0 16
jsa1969 0:cef60cc92da0 17 if (buffer == NULL || length <= 0)
jsa1969 0:cef60cc92da0 18 return MICROBIT_INVALID_PARAMETER;
jsa1969 42:ce269f988ac8 19
jsa1969 42:ce269f988ac8 20 acquireLock();
jsa1969 40:a67a880cb538 21 result = _i2c->write(address, (const char *)&reg, 1, true);
jsa1969 42:ce269f988ac8 22 if (result == 0)
jsa1969 42:ce269f988ac8 23 result = _i2c->read(address, (char *)buffer, length);
jsa1969 42:ce269f988ac8 24 _locked = false;
jsa1969 42:ce269f988ac8 25
jsa1969 42:ce269f988ac8 26 return result != 0 ? MICROBIT_I2C_ERROR : MICROBIT_OK;
jsa1969 0:cef60cc92da0 27 }
jsa1969 0:cef60cc92da0 28
jsa1969 15:8bb5c580d453 29 int I2cCallbacks::read(const uint8_t address, uint8_t *buffer, const uint16_t length){
jsa1969 2:544117df8c65 30 int result;
jsa1969 2:544117df8c65 31
jsa1969 2:544117df8c65 32 if (buffer == NULL || length <= 0)
jsa1969 2:544117df8c65 33 return MICROBIT_INVALID_PARAMETER;
jsa1969 2:544117df8c65 34
jsa1969 42:ce269f988ac8 35 acquireLock();
jsa1969 40:a67a880cb538 36 result = _i2c->read(address, (char *)buffer, length);
jsa1969 43:f968ca84d4ed 37 _locked = false;
jsa1969 42:ce269f988ac8 38
jsa1969 2:544117df8c65 39 if (result !=0)
jsa1969 2:544117df8c65 40 return MICROBIT_I2C_ERROR;
jsa1969 2:544117df8c65 41
jsa1969 2:544117df8c65 42 return MICROBIT_OK;
jsa1969 2:544117df8c65 43 }
jsa1969 2:544117df8c65 44
jsa1969 15:8bb5c580d453 45 int I2cCallbacks::write(const uint8_t dev_id, const uint8_t reg_addr, const uint8_t *data, const uint16_t length){
jsa1969 2:544117df8c65 46 char tmpBuf[length+1];
jsa1969 0:cef60cc92da0 47 tmpBuf[0] = reg_addr;
jsa1969 0:cef60cc92da0 48 for (int i=0,j=1; i <length ; ++i,++j){
jsa1969 0:cef60cc92da0 49 tmpBuf[j] = data[i];
jsa1969 0:cef60cc92da0 50 }
jsa1969 0:cef60cc92da0 51
jsa1969 42:ce269f988ac8 52 acquireLock();
jsa1969 42:ce269f988ac8 53 int result = _i2c->write(dev_id, tmpBuf, length+1);
jsa1969 42:ce269f988ac8 54 _locked = false;
jsa1969 42:ce269f988ac8 55
jsa1969 42:ce269f988ac8 56 return result;
jsa1969 0:cef60cc92da0 57 }
jsa1969 0:cef60cc92da0 58
jsa1969 15:8bb5c580d453 59 int I2cCallbacks::write(const uint8_t dev_id, const uint8_t *data, const uint16_t length){
jsa1969 42:ce269f988ac8 60 acquireLock();
jsa1969 42:ce269f988ac8 61 int result = _i2c->write(dev_id, (char*)data, length);
jsa1969 42:ce269f988ac8 62 _locked = false;
jsa1969 42:ce269f988ac8 63 return result;
jsa1969 42:ce269f988ac8 64 }
jsa1969 42:ce269f988ac8 65
jsa1969 42:ce269f988ac8 66 void I2cCallbacks::delay_ms_relaxed(const uint32_t period) {
jsa1969 42:ce269f988ac8 67 _uBit->sleep(period);
jsa1969 2:544117df8c65 68 }
jsa1969 2:544117df8c65 69
jsa1969 42:ce269f988ac8 70 void I2cCallbacks::delay_ms_strict(const uint32_t period) {
jsa1969 42:ce269f988ac8 71 unsigned long endTime = _uBit->systemTime() + period;
jsa1969 42:ce269f988ac8 72 acquireLock();
jsa1969 42:ce269f988ac8 73 while (_uBit->systemTime() < endTime) {
jsa1969 42:ce269f988ac8 74 }
jsa1969 42:ce269f988ac8 75 _locked = false;
jsa1969 0:cef60cc92da0 76 }
jsa1969 42:ce269f988ac8 77
jsa1969 42:ce269f988ac8 78 void I2cCallbacks::acquireLock() {
jsa1969 42:ce269f988ac8 79 while (_locked) _uBit->sleep(1);
jsa1969 42:ce269f988ac8 80 _locked = true;
jsa1969 42:ce269f988ac8 81 }