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 Studio 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