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Improve ccs811 precision (#1428)

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Zixuan Wang 2021-01-21 23:51:40 -08:00 committed by GitHub
parent b28735d63b
commit 8352f52fef
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1 changed files with 8 additions and 4 deletions
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esphome/components/ccs811/ccs811.cpp
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@ -102,10 +102,14 @@ void CCS811Component::send_env_data_() {
// temperature has a 25° offset to allow negative temperatures
temperature += 25;
// only 0.5 fractions are supported (application note)
auto hum_value = static_cast<uint8_t>(roundf(humidity * 2));
auto temp_value = static_cast<uint8_t>(roundf(temperature * 2));
this->write_bytes(0x05, {hum_value, 0x00, temp_value, 0x00});
// At page 18 of:
// https://cdn.sparkfun.com/datasheets/BreakoutBoards/CCS811_Programming_Guide.pdf
// Reference code:
// https://github.com/adafruit/Adafruit_CCS811/blob/0990f5c620354d8bc087c4706bec091d8e6e5dfd/Adafruit_CCS811.cpp#L135-L142
uint16_t hum_conv = static_cast<uint16_t>(lroundf(humidity * 512.0f + 0.5f));
uint16_t temp_conv = static_cast<uint16_t>(lroundf(temperature * 512.0f + 0.5f));
this->write_bytes(0x05, {(uint8_t)((hum_conv >> 8) & 0xff), (uint8_t)((hum_conv & 0xff)),
(uint8_t)((temp_conv >> 8) & 0xff), (uint8_t)((temp_conv & 0xff))});
}
void CCS811Component::dump_config() {
ESP_LOGCONFIG(TAG, "CCS811");