HDC2010EVM: Humidity data is not linear at over 60-%.

Hi AC guy,

Thanks for sharing the data.
Bit 5 of reg 0x4 is TL_STATUS, the Lower threshold value programmed that will trigger an interrupt from "0" to "1" when the measured temp goes below the predetermined value. What value was programmed there, reg 0x00?

The other behavior is not something expected. We will have to check in our labs. SInce Monday is holiday in US someone will reply on Tuesday with results of the investigation.

Regards,
Jose

Hello Jose,

Thank you for reply and your concern.
They tried devices swap on two EVMs. Issues are incident on devices.
They didn't modify the firmware for MSP430. It remains in its initial state.

If their EVMs are failed, please let me know the similar case and solution.

Regards,
ACGUY

AC guy,

As Jose mentioned, register 0x04 is an interrupt register and will convey if any thresholds have been tripped during device operation.

Can you verify what happens when register 0x09 is programmed to '0'? Can you confirm if this offset value changes during operation? We'll have to confirm in the lab, but expect to have some more information and will update the post accordingly.

Best Regards,
Matt

Hello specialist,

I captured the GUI movie. Please look at those attachments.

"Data streaming.wmv"

At room (normal room environment), ambient temperature was to be -40degC instantaneously. Humidity was to be 0% too. We didn't use the liquid nitrogen.

"Regs.wmv"

Measured under the same conditions as above.

Address 0x04 (time at 01:05) and 0x09 (time at 02:25) value are frequentry modified. We didn't change the firmware. It's left default.

Is device broken? Please let me know the cause.

Regards,

ACGUY

Hi ACGUY,

You may need to navigate to another page to set the conversion rate (data output rate) of the device, as the register read is much faster than the default data output rate (1s).  Register 0x04 is periodically outputting 0x20, because each period is specifying that the temperature low limit is being tripped. I've noticed that the temperature lower limit is programed to 0x8E, which translates to a lower temperature value of 51.52, therefore it can be seen that after each period of conversion, the device will output 0x20 on register 0x04.

The humidity offset register seems like it may be a software issue, however I would need to verify if I see any unusual behavior in my studies.

Can you turn off the autoread and confirm this issue by performing a manual read?  This would be my next recommendation.

Best Regards,

Matt

Hi Matt,

Thank you for reply.

>> Can you turn off the autoread and confirm this issue by performing a manual read?
->No. I could not it by manual.

>> The humidity offset register seems like it may be a software issue,
-> I see. Can I solve this problem by changing the register on GUI? Or, necessary to change the firmware?

Regards,
ACGUY