Code Doesn't Match Sensirion Datasheet

[TFenby]

Sensirion_Datasheet_SFA40.pdf

Specifically, the commands don't match:

#define SAF40_COMMAND_START      0x00AC 
#define SAF40_COMMAND_READ       0xE06D 
#define SAF40_COMMAND_STOP       0x50D2 
#define SAF40_COMMAND_ID         0x02CE

and the status doesn't match:

uint8_t DFRobot_SFA40::readMeasurementData(void){
  memset(_buf,0,12);
  readReg(SAF40_COMMAND_READ,_buf,12);
  // HCHO= NAN;  
  // humidity=NAN;
  // temperatureC=NAN;
  // temperatureF=NAN;
  if(_buf[10]==0){  // <-- here, and other _buf[10] references

[YeezB]

Hi there,
I'm the product manager for the Gravity SFA40 HCHO sensor. We have verified with the chip manufacturer Sensirion that all previously sold DFRobot SFA40 sensors were built upon their B4 pre-release samples.
The B4 sample is the final prototype before the official SFA40 launch. It features identical performance to the formal release version. The only minor differences are in the datasheet, mainly regarding register definitions. Sensirion has not disclosed the reason for these register adjustments, and we suspect this was to protect technical details prior to the official product release.
A new batch of Gravity SFA40 sensors with the official SFA40 chip will be available in our store this July or August. We will roll out corresponding software updates for the official version, while still maintaining compatibility with the original B4 sample code. Detailed explanations will also be added to our official documentation.
Thanks for your attention.

[TFenby]

Interesting! Thank you for the reply. Is there a way to identify those B4 pre-release samples? I’m making a component for ESPHome, so ideally there would be a way to auto detect the registers that need to be used. Maybe the serial number? Have you seen a different serial number range for prerelease vs production chips?