Hello,
I’m a student who wants to use the CO2 sensor SGP30 (GROVE) but when we follow the tutorial available here : Grove - VOC and eCO2 Gas Sensor(SGP30) - Seeed Wiki the baseline example is working well but the answer showed by the monitor is not the language expectd by the tutorial. We can see that on the window :
The code is :
#include <Arduino.h>
#include <EEPROM.h>
#include "sensirion_common.h"
#include "sgp30.h"
#define LOOP_TIME_INTERVAL_MS 1000
#define BASELINE_IS_STORED_FLAG (0X55)
//#define ARRAY_TO_U32(a) (a[0]<<24|a[1]<<16|a[2]<<8|a[3]) //MSB first //Not suitable for 8-bit platform
void array_to_u32(u32* value, u8* array) {
(*value) = (*value) | (u32)array[0] << 24;
(*value) = (*value) | (u32)array[1] << 16;
(*value) = (*value) | (u32)array[2] << 8;
(*value) = (*value) | (u32)array[3];
}
void u32_to_array(u32 value, u8* array) {
if (!array) {
return;
}
array[0] = value >> 24;
array[1] = value >> 16;
array[2] = value >> 8;
array[3] = value;
}
/*
Reset baseline per hour,store it in EEPROM;
*/
void store_baseline(void) {
static u32 i = 0;
u32 j = 0;
u32 iaq_baseline = 0;
u8 value_array[4] = {0};
i++;
Serial.println(i);
if (i == 3600) {
i = 0;
if (sgp_get_iaq_baseline(&iaq_baseline) != STATUS_OK) {
Serial.println("get baseline failed!");
} else {
Serial.println(iaq_baseline, HEX);
Serial.println("get baseline");
u32_to_array(iaq_baseline, value_array);
for (j = 0; j < 4; j++) {
EEPROM.write(j, value_array[j]);
Serial.print(value_array[j]);
Serial.println("...");
}
EEPROM.write(j, BASELINE_IS_STORED_FLAG);
}
}
delay(LOOP_TIME_INTERVAL_MS);
}
/* Read baseline from EEPROM and set it.If there is no value in EEPROM,retrun .
Another situation: When the baseline record in EEPROM is older than seven days,Discard it and return!!
*/
void set_baseline(void) {
u32 i = 0;
u8 baseline[5] = {0};
u32 baseline_value = 0;
for (i = 0; i < 5; i++) {
baseline[i] = EEPROM.read(i);
Serial.print(baseline[i], HEX);
Serial.print("..");
}
Serial.println("!!!");
if (baseline[4] != BASELINE_IS_STORED_FLAG) {
Serial.println("There is no baseline value in EEPROM");
return;
}
/*
if(baseline record in EEPROM is older than seven days)
{
return;
}
*/
array_to_u32(&baseline_value, baseline);
sgp_set_iaq_baseline(baseline_value);
Serial.println(baseline_value, HEX);
}
void setup() {
s16 err;
u16 scaled_ethanol_signal, scaled_h2_signal;
Serial.begin(115200);
Serial.println("serial start!!");
/*For wio link!*/
#if defined(ESP8266)
pinMode(15, OUTPUT);
digitalWrite(15, 1);
Serial.println("Set wio link power!");
delay(5000);
#endif
/* Init module,Reset all baseline,The initialization takes up to around 15 seconds, during which
all APIs measuring IAQ(Indoor air quality ) output will not change.Default value is 400(ppm) for co2,0(ppb) for tvoc*/
while (sgp_probe() != STATUS_OK) {
Serial.println("SGP failed");
while (1);
}
/*Read H2 and Ethanol signal in the way of blocking*/
err = sgp_measure_signals_blocking_read(&scaled_ethanol_signal,
&scaled_h2_signal);
if (err == STATUS_OK) {
Serial.println("get ram signal!");
} else {
Serial.println("error reading signals");
}
// err = sgp_iaq_init();
set_baseline();
//
}
void loop() {
s16 err = 0;
u16 tvoc_ppb, co2_eq_ppm;
err = sgp_measure_iaq_blocking_read(&tvoc_ppb, &co2_eq_ppm);
if (err == STATUS_OK) {
Serial.print("tVOC Concentration:");
Serial.print(tvoc_ppb);
Serial.println("ppb");
Serial.print("CO2eq Concentration:");
Serial.print(co2_eq_ppm);
Serial.println("ppm");
} else {
Serial.println("error reading IAQ values\n");
}
store_baseline();
}Thank you.
Yanis