PMod ambient light sensor units

[Nick Conklin]

I have a PMod ALS in my design, and it works well. However, I don't know how to convert ADC units back to physical units. The documentation is no help. Can someone please provide this information, or is it something that I need to figure out how to measure myself?

[JColvin]

Hi @Nick Conklin,

The datasheet for the embedded ADC081S021, specifically section 8 and Figure 2 in section 7.6 https://www.ti.com/lit/ds/symlink/adc081s021.pdf, will be of the most help for figuring out how the TI ADC organizes it's data.

Many years ago (clarifying this detail since this document isn't linked on the resource center nor been looked at for accuracy), I wrote a bit of extra information on how the 8-bits of usable data are organized in the 15 bits of data from the ADC here: https://digilent.com/reference/pmod/pmodals/user-guide#communication_protocol, though I think I replicated this information in the Interfacing with the Pmod section of the Reference Manual, https://digilent.com/reference/pmod/pmodals/reference-manual.

Regardless, I do not disagree that the information is hard to parse. I will see about getting some sort of timing diagram into the reference manual if I get the opportunity.

Thanks,
JColvin