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The SCD4x is Sensirion’s next generation miniature CO2 sensor. This sensor builds on the photoacoustic NDIR sensing principle and Sensirion’s patented PASens® and CMOSens® technology to offer high accuracy at an unmatched price and smallest form factor. SMD assembly allows cost- and space-effective integration of the sensor combined with maximal freedom of design. On-chip signal compensation is realized with the built-in SHT4x humidity and temperature sensor.CO2 is a key indicator for indoor air quality (IAQ) as high levels compromise humans’ cognitive performance and well-being. The SCD4x enables smart ventilation systems to regulate ventilation in the most energy-efficient and human-friendly way. Moreover, indoor air quality monitors and other connected devices based on the SCD4x can help maintain low CO2 concentration for a healthy, productive environment.
LibDriver SCD4X is a full function driver of SCD4X launched by LibDriver.It provides CO2 reading, temperature reading, humidity reading and other functions. LibDriver is MISRA compliant.
/src includes LibDriver SCD4X source files.
/interface includes LibDriver SCD4X IIC platform independent template.
/test includes LibDriver SCD4X driver test code and this code can test the chip necessary function simply.
/example includes LibDriver SCD4X sample code.
/doc includes LibDriver SCD4X offline document.
/datasheet includes SCD4X datasheet.
/project includes the common Linux and MCU development board sample code. All projects use the shell script to debug the driver and the detail instruction can be found in each project's README.md.
/misra includes the LibDriver MISRA code scanning results.
Reference /interface IIC platform independent template and finish your platform IIC driver.
Add the /src directory, the interface driver for your platform, and your own drivers to your project, if you want to use the default example drivers, add the /example directory to your project.
You can refer to the examples in the /example directory to complete your own driver. If you want to use the default programming examples, here's how to use them.
#include "driver_scd4x_basic.h"
uint8_t res;
uint32_t i;
uint32_t times = 3;
uint16_t co2_ppm;
float temperature;
float humidity;
/* basic init */
res = scd4x_basic_init(SCD41);
if (res != 0)
{
return 1;
}
...
/* loop */
for (i = 0; i < times; i++)
{
/* delay 5000ms */
scd4x_interface_delay_ms(5000);
/* read data */
res = scd4x_basic_read((uint16_t *)&co2_ppm, (float *)&temperature, (float *)&humidity);
if (res != 0)
{
(void)scd4x_basic_deinit();
return 1;
}
/* output */
scd4x_interface_debug_print("scd4x: %d/%d.\n", (uint32_t)(i + 1), (uint32_t)times);
scd4x_interface_debug_print("scd4x: co2 is %02dppm.\n", co2_ppm);
scd4x_interface_debug_print("scd4x: temperature is %0.2fC.\n", temperature);
scd4x_interface_debug_print("scd4x: humidity is %0.2f%%.\n", humidity);
...
}
...
/* basic deinit */
(void)scd4x_basic_deinit();
return 0;
#include "driver_scd4x_shot.h"
uint8_t res;
uint32_t i;
uint32_t times = 3;
uint16_t co2_ppm;
float temperature;
float humidity;
/* shot init */
res = scd4x_shot_init(SCD41);
if (res != 0)
{
return 1;
}
...
/* loop */
for (i = 0; i < times; i++)
{
/* delay 5000ms */
scd4x_interface_delay_ms(5000);
/* read data */
res = scd4x_shot_read((uint16_t *)&co2_ppm, (float *)&temperature, (float *)&humidity);
if (res != 0)
{
(void)scd4x_shot_deinit();
return 1;
}
/* output */
scd4x_interface_debug_print("scd4x: %d/%d.\n", (uint32_t)(i + 1), (uint32_t)times);
scd4x_interface_debug_print("scd4x: co2 is %02dppm.\n", co2_ppm);
scd4x_interface_debug_print("scd4x: temperature is %0.2fC.\n", temperature);
scd4x_interface_debug_print("scd4x: humidity is %0.2f%%.\n", humidity);
...
}
...
/* shot deinit */
(void)scd4x_shot_deinit();
return 0;
Online documents: https://www.libdriver.com/docs/scd4x/index.html.
Offline documents: /doc/html/index.html.
Please refer to CONTRIBUTING.md.
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