Maxim Integrated MAX86140 - Proximity Configuration; System Control; Data Logging; Register Map Access

Maxim Integrated │ 17
www.maximintegrated.com
Evaluates: MAX86140 and MAX86141
MAX86140/MAX86141
Evaluation System
Proximity Conguration
The optical controller also includes an optical proximity
function which could signicantly reduce energy
consumption and extend battery life when the sensor is
not in contact with the skin.
Please refer to the MAX86140/MAX86141 datasheet
under Proximity Mode Section for details.
System Control
When MAX86141 is used, there is option to use single PD
(PD1) or Dual PD simultaneously (PD1 and PD2). When
Dual PD mode is used, the data log will shows data from
both PD for each congured sequence.
<Start >/<Stop > Button
The <Start Monitor> button is used to start data acquisition
from the demo. The <Start Monitor> button will only be
e󰀨ective when the EVSYS is connected and detected.
Once the <Start > has been pushed the <Stop> button
appears, which can be used to stop the acquisition.
Once the acquisition has started, all settings are locked.
Terminate the acquisition to change any settling.
<Reset> Button
The <Reset> button will clear out all register settlings
back to the programs start up.
Data Logging
Raw optical and accelerometer data can be logged from
the <Logging> pull-down menu item. There are two
options available: Data saved to le or in the ash. When
“le” data logging is selected, the GUI asks for a folder
location where the logging le will be saved. Create a
new folder or accept the default. Data logging will start on
the next <Start> button and will continue until the <Stop
> button is pressed. The nal le write is only done when
the <File> pull-down menu item is accessed and the data-
logging button is pressed.
Flash logging allows raw sensor data to be stored to
the integrated 32MB ash memory chip in a binary le
format. The max duration for ash logging is dependent
on: sample rate, number of optical channels, and use of
accelerometer.
The GUI enables/disables ash logging. The GUI can
be disconnected while ash logging, allowing for remote
operation (PPG Plots not available). Preparing the ash
memory can take up to 30s after enabling. If the ash
memory lls or battery power drops too low, ash logging
will automatically stop and the le will close. Only one
le can be saved at a time. The le must be downloaded
since it will be erased on the next log request.
If a log has completed, a binary le will be found on the
device. The binary log le must be downloaded via the
USB-C cable; it cannot be downloaded through BLE.
When the device is plugged into the PC, it enumerates as
a USB mass storage device. However, the le can only
be copied from this device. No other operations (such
as deleting or saving other les) will work on this device.
Copy the le to a local PC volume. Then run the parser to
generate a CSV le.
Please refer to the Evaluation Kit Parser User Guide
(max8614x demo + eval kit parser user guide 20170719.
pdf) for details operation.
Register Map Access
Under the <Register> Tab the user can access to sensor
register map as shown in Figure 17. Press <Read All>,
to read all the register value currently in congured in the
Optical AFE. Bolded font bits are logic one. Normal font
bits are logic zero. Click on the bits to toggle their value
and click on <W> to write the value to the device. The
register value does not change until <W> is clicked. Click
<R> to read the register value to verify the write.