HDC2010: HDC2010 Readings

Hi Donald,

Where are you reading that the two LSB should be 00? I think this is a misunderstanding.

Thanks,
Ren

Hi Ren,

Thanks for the speedy response.  

I am reading the upper and lower bytes of the Temperature and Humidity registers.

I am using single acquisition mode with 11 bit resolution.  What I found was that when I was writing h01 to trigger a measurement in the 0F Configuration register I may also have been switching resolution back to 14 bit and that may have confused the chip.  Some experimenting shows that is not the case.  I am not aware of a way to change one bit in a I2C device without affecting the other 7 bits unless you rewrite the whole byte with what you need.

 

Those last two digits are of little practical value to me but I did expect them to be 00. 

 

Thanks for any light you can shine on this.

 

Don Pierman

 

PS:

 

I also found that when reading the four registers for Temp and Humidity using an HCS08 NXP MC you must turn off Transmit Acknowledge in the MC before reading the Humidity High Byte which is the last of the four or IIC_Stop will not happen and the SDA line will be pulled low and stay there until the power is removed and reconnected.

I think some of the confusion from me is the use of LSB when I should have used lsb as this was about the least two bits not bytes. Documentation should have used lsb as well. It also appears that in Application Report SNAA312 August 2018 on page 3, the Example Flowchart For A Single Acquisition Configuration, the second instruction down the flowchart refers to correctly using address OF but the example to the right of that uses erroneously, address OE.

Thanks Josh,
What started this line of questioning are the least significant two bits in the least significant byte of the temperature register and the same in the humidity register. I'm getting data in both of those rather than 00's.

I have setup the HDC2010 to use 11 bit resolution for temperature and for humidity but I am getting data all the way out to the least significant bit of temperature and humidity readings. Using 11 bit resolution I should have five "0's" in the least significant positions of both temperature and humidity registers. Eleven bits should use less power than 14 bit resolution.

I'm guessing that when you write to the OF register to set the Trigger bit to start conversion you must also include setting the resolution bits (that are already set) or you will change the resolution, unless my guess is wrong.

Any help on this subject will be greatly appreciated.

Don Pierman