Tool/software:
Hello,
Note: these settings can be saved and entered into the AFE4900 EVM as a xxx.cfg file.
I am hoping that someone who has ACTUALLY USED the AFE4900 responds to this post.
My configuration is as follows:
LED1 - green
LED2 - red
LED3 - IR
LED4 - green2
What I attempted to configure was
LED1 pulse - sample - convert
and ambient sample - convert
and save to FIFO.
but it appears that does not work.
For some reason it wants
LED2 ( pulse - sample - convert )
LED1 ( pulse - sample - convert )
so I set LED2 drive current to 0 milliamps as a work around.
This is a power constrained device - I assume extra phases are not good for
minimum power consumption.
I created a configuration like this for the AFE4900 EVM
it also mis-behaves - It is attached.
Can someone please explain to me the underlying assumption
about the phase order and what is needed ?
The datasheet says that setting a count register to >PRPCOUNT should disable it - but there is
something else going on in the LED1 only configuration.
The timing calculator.xls spreadsheet only works for all 4 phases - anything else gives an error.bad_config2.cfg
The AFE4900 EVM is also unhappy with only 1 LED1 phase.
I can successfully gather data, but I have used other PPG IC's from other manufacturers
and had no limitations such as this.
I also plan on using LED2 and LED3 as a sampling pair for SPO2.
If someone had a RTL description or VHDL of the part I would be able to understand it's timing
sequencing limitations.
Looking forward to hearing from you.
JBS
