ScioSense PCap04-EVA-KIT V2.0 User manual

Development Kit User Guide
PCap04-EVA-KIT V2.0
PCAP04-EVA-KIT 2.0
Revision: 2
Release Date: 2023-05-16
Document Status: Production

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Content Guide
Content Guide .................................................................................................... 2
1Introduction ................................................................................................. 3
1.1 Ordering Codes .........................................................................................3
2Quick Start Guide .......................................................................................... 3
2.1 Installing the Software.................................................................................3
2.2 Installing the Hardware................................................................................4
2.3 Quick Start for Initial Measurements ................................................................4
3Hardware Description ..................................................................................... 7
3.1 PCap04 Lite Board......................................................................................7
3.1.1 Capacitance Measurement .......................................................................7
3.1.2 Temperature Measurement ......................................................................7
1Software Description ...................................................................................... 9
1.1 Initialization.............................................................................................9
1.2 Graphical User Interface ..............................................................................9
1.2.1 Front Panel .........................................................................................9
3.1.3 Front Panel Menus............................................................................... 22
3.1.4 Special Windows ................................................................................. 25
3.1.5 Linearize .......................................................................................... 31
3.2 Scaling Results ........................................................................................ 37
3.3 Scaling PDM Output .................................................................................. 39
4Schematics, Layers & BOM .............................................................................. 40
5RoHS Compliance & ScioSense Green Statement.................................................... 42
6Copyrights & Disclaimer.................................................................................. 42
7Revision information ..................................................................................... 43

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1Introduction
The PCap04-EVA-KIT V2.0 evaluation system provides a complete system for generally evaluating the
PCap04 IC. It is supplied with a main board, a plug-in board, a Windows based evaluation software,
assembler software and the PicoProg Lite communication interface. The kit includes the following
elements:
PCap04 LITE V1.0 BGRP
PicoProg Lite V1.0
USB to USB-C data cable
Figure 1: Elements of the development kit
Please download the software for the kit from https://downloads.sciosense.com/PCAP04 and look
for the latest revision.
1.1 Ordering Codes
Table 1: Pin description
Ordering code
Part Number
Description
PCap04-EVA-KIT V2.0
220300004
PCap04 LITE board & PicoProg Lite & USB-C cable
PCap04 LITE V1.0 BGRP
220300005
PCap04 evaluation board
2Quick Start Guide
In this section, we described how to set up quickly the PCap04-EVA-KIT V2.0 and establish basic
operation and make measurements.
2.1 Installing the Software
It is crucial to install the software before connecting the evaluation kit to your computer. A default
driver loading of your OS may interfere with correct installation.
•Download the latest zipped software installation package to the desired directory.
https://downloads.sciosense.com/PCAP04
•Unzip the package to the desired directory.
•Open “setup.exe” from the unzipped directory.
•Follow the instructions on the screen.

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2.2 Installing the Hardware
•Connect the PicoProg Lite PCB to the computer by means of the USB cable. The green LED should
be on.
•Connect the PCap04 LITE to the PicoProg Lite. Two connectors are available, one for SPI
communication and one for I2C communication. They are marked accordingly.
2.3 Quick Start for Initial Measurements
In the START menu search for PCap04 or look under program folder ScioSense for the PCap04 software
and start it. The software pops up with the following window:
Figure 2: Start page
On the right site a little icon indicates whether a device is connected and whether SPI or I2C is used.
Click the “Verify Interface” button to confirm communication with PicoProg Lite and PCap04 is
working:

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Figure 3: Verify
The PCap04 plug-in board is pre-assembled with ceramic capacitors to emulate capacitive sensors.
These capacitors, each 10 pF in value, are connected to the 6 ports PC0 to PC5.
To begin measurements using these preinstalled components, it is necessary to make the following
adjustments on the “CDC Frontend” tab:
1) “Capacitive Measurement Scheme” section should be set to “Floating | Single”.
2) All the capacitance ports should be turned on using the Cap. Port. Select buttons
3) The Stray Compensation setting should be set to “Both”.
The resulting settings under the CDC tab should look like this:
Figure 4: CDC Frontend page at the start

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To begin measurements, on the right side of the window, click the following buttons in the order
listed:
1) “Power On Reset”
2) “Write Complete”
3) “Start Measurement”
Measurements should now be running and your screen should resemble the following:
Figure 5: CDC Frontend page with running measurement
The C1 and C2 values should be continually updating but remain within a reasonably small standard
deviation as shown.
At this point the above steps have been successfully completed and the operation of the EVA kit can
be done. The following sections provide a detailed description of the hardware and software for
advanced operation.

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3Hardware Description
3.1 PCap04 Lite Board
3.1.1 Capacitance Measurement
For the purpose of evaluating the capacitance measurement using PCap04, the board is pre-
assembled with ceramic capacitors to emulate capacitive sensors. These capacitors, each 10 pF in
value, are connected to the 6 ports PC0 to PC5. They are connected as single sensors in floating
mode, i.e. each capacitor is connected between 2 ports, and hence there are 3 x 10 pF on-board
capacitors. Please refer to section 3 of the PCap04 data sheet for more information on how to
connect capacitors to the chip. In case using external reference, the capacitor connected between
ports PC0 and PC1 is taken as the reference capacitor.
Figure 6: Details of the plug-in board (A=three C0G ceramic capacitors)
In the process of evaluation, when you are comfortable with interpreting the measurement results
from the chip, these fixed capacitors can be replaced with the actual capacitive sensors of your
application.
If you want to connect your capacitive sensors in grounded mode, then GND points are provided at
the two corners of the board, where the sensor ground connections ought to be soldered.
The typical value of the capacitive sensors that can be connected to the evaluation kit lies in the
range of 30 pF to 3.5 nF. The reference capacitor should be in the same order of magnitude as the
sensor. Depending on the value of the sensor, the value of the internal resistor for performing the
measurement has to be selected. For the pre-assembled 10 pF capacitors, an internal discharge
resistor of 90 kΩ works well. See section 3 of the PCap04 data sheet on how to select the value of
the internal discharge resistor.
3.1.2 Temperature Measurement
Temperature measurement or other resistive tasks may also be of interest for the user of this kit.
The evaluation kit offers this possibility through the RDC (resistive-to-digital converter) ports. An on-
chip thermistor coupled with an on-chip temperature-stable reference resistor made of polysilicon
is sufficient for observing the temperature measurement capability of the PCap04 chip.
A

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Figure 7: Temperature sensor connection pads
A Port PT1 for second external temperature sensor (not supported by the standard firmware)
B Port PT0 for external temperature sensor
C Port PT2 for external reference resistor
D 10 nF COG
However, there is a possibility to connect the reference resistor and the thermistor externally to
the chip, too. In case of external resistors, the temperature-stable reference resistor ought to be
connected at port PT2REF on the plug-in board. The board allows you to connect the external
thermistor, e.g. a PT1000 sensor at port PT0 (or PT1, not supported yet by the standard firmware).
In any case, for the temperature measurement, an external capacitor 10 nF C0G has to be
connected to the chip; it is already pre-assembled on board.
D
C
B
A

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1Software Description
1.1 Initialization
Configuration files, Firmware, Settings and Calibration Data are subsumed in a project (.prj) file.
When opening a project file then automatically the configuration and firmware data will be
transferred to the chip and the chip is initialized.
Step 1: The first to do after starting the evaluation software is to read the device version from Chip
by pressing the button or to select the supported PICOCAP device on the setup page. In the initial
phase start with our standard firmware that calculates the capacitance ratios and resistance ratios.
It automatically recognizes the operation mode and takes care of the set number of capacitors and
the kind of connection. But it does no further processing.
Step 2: If you want to change from the default SPI to I2C interface, please select under Interface --
> Bus --> I2C. The LED on the PicoProg Lite interface should now turn red. When the LED does not
glow at all, then it indicates that the interface is faulty.
Step 3: By pressing the ‘Standard’-button, the standard project file will be open.
You also may load your own project file.
Step 4: Open Graph window and press ‘Start Measurement’.
1.2 Graphical User Interface
Next, the main front panel comes up. Overall, the graphical user interface offers various windows
for on-line configuration, for parameter and calibration data setting, and of course for the graphical
and numerical display of the measurement data. The various windows will be explained in this
chapter.
1.2.1 Front Panel
This is the main window. On the right side, the front panel shows six general buttons:
Open Graph
Open a window for graphic representation of measurement data
Start Measurement
Start or stop a running measurement
Write Config.
Transfer once more, the present settings in the evaluation software to the chip (in case of
doubt)
Write Complete
Transfer the complete firmware, calibration data and configuration to the chip
Power On Reset
After Power up reset, ‘Write Config.’ may be necessary.
Init Reset
With an init reset, the chip is re-initialized with respect to its frontend and processor.

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1.2.1.1 Setup Page
Figure 8 Setup page
Options on ‘Setup’ page:
Standard
Opens the <Selected Device>_standard.prj project file with configuration and standard
firmware.
Humidity
Opens the <Selected Device>_humidity.prj project file with configuration and linearization
firmware.
Pressure
Opens the <Selected Device>_pressure.prj project file with configuration and linearization
firmware.
Verify Interface
When everything is in order, then pressing this button will indicate the release version
number of the software and of the PicoProg Lite / PICOPROG V3.0 Firmware. It also
confirms with ‘Memory read/write: OK’ if a supported PICOCAP device is present.
The lower part of the window is used for real-time numerical display of the measurement results. In
principle it shows the content of the read registers. The content itself depends on the firmware.
Figure 8 shows the content as it is given with the standard firmware. The first six rows show the
capacitance ratios, the last two rows show the temperature result (resistance ratio or linearized
temperature).

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The tab has 12 columns of information, defining labels, data format, resolution specification (white
background) and results (grey background). The information in the white fields increase convenience
of reading and is stored in the project files (*.prj). All number may get a character to indicate the
well-known prefixes for denoting the factor in thousands (‘p’, ‘f’, ‘a’, ‘k’... ).
Name
Label for the register content, depends on the firmware.
Results
Raw hex data display of the result register content. The column before shows the width. The
button column after shows whether the result is signed or unsigned.
Filter
Selection of various software filters like Sinc (rolling average) and Median (non-linear filter).
fpp
This column shows the size of the fractional part of the fixed point number and the necessary shift.
Depends on the firmware.
Factor
The factor is a scaling factor that allows to scale the result according to the reference capacitor.
Factor = ‘1’ gives back the initial capacitance ratio in column ‘Final Result’.
Offset
Offset to be added or subtracted in the evaluation software.
Auto Offset
By pressing [AO], the software re-calculates the ‘Offset’, setting back the ‘Final Result’ to 0
Span
Number that defines the maximum span of the sensor. Is relevant only for the calculation of the
resolution in column SNR [bit].
Final Result
Display of the final result, scaled by ‘Factor’ and the ‘Offset’ added.
Mean
Display of the mean value. The sample size can be selected.
Std.Dev
Standard deviation of the ‘Final Result’.
SNR [bit]
Signal-to-Noise ratio in bit, calculated as ‘Span’/ ‘Std.Dev.’

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1.2.1.2 CDC Frontend Page
Figure 9 CDC Frontend page

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Options on ‘CDC Frontend’ page:
Capacitance Measurement
Scheme
Grounded | Single –Single capacitive sensor connected between a port and ground.
Grounded | Differential –Differential capacitive sensor connected between 2 ports
with the middle tap of the sensor connected to ground.
Floating | Single –Single capacitive sensor connected between 2 ports.
Floating | Differential –Differential capacitive sensor connected between 2 ports with
the middle tap of the sensor connected to another 2 ports.
Cap. Port Select
Select which capacitive ports have to be measured (Ports 0-5), i.e. at which ports the
sensors have been connected in hardware.
Stray Compensation
None –No compensation
Internal –One additional measurement performed through only the chip-internal stray
capacitance with respect to ground.
External –One additional measurement per port pair, performed through a parallel
connection of the capacitance at the two ports with respect to ground.
Both –Both internal and external compensation together.
Discharge Resistance Port
0..3
Selects the value of the internal resistance (180k, 90k, 30k, 10k) for measurements on
port PC0 to PC3 through which the discharge cycles during measurement are to be
performed. This value has to be selected in accordance with the capacitance value of
the sensor.
Discharge Resistance Port
4..5
Selects the value of the internal resistance (180k, 90k, 30k, 10k) for measurements on
port PC4 to PC5 through which the discharge cycles during measurement are to be
performed. This value has to be selected in accordance with the capacitance value of
the sensor.
Charge Resistance
Choice of one out of 4 on-chip charging resistors (180k, 10k) for the CDC. Permitting
to limit the charging current and avoiding transients.
C Reference Select
Switching between external and internal reference capacitance.
Internal Cap
Selection of internal reference capacitance value. (0..31pF)

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1.2.1.3 CDC Page
Figure 10 CDC page
Options on ‘CDC’ page:
Cycle Control
Precharge Time
Time to charge via resistor for current limitation, can be set in multiples of the cycle clock
Fullcharge Time
Time for final charge without current limitation, can be set in multiples of the cycle clock
Discharge Time
Time to discharge the capacitor, can be set in multiples of the cycle clock
C_FAKE
Number of fake measurements per measurement cycle. Performing fake measurements
may help in reducing noise.
C_AVRG
Enables averaging the measurement results over multiple measurement cycles. Setting
to 1 →No averaging, Setting to any number N, will result in averaging over N
measurement cycles for generating one measurement result. (0..8191)
Cycle Clock Select
50,0kHz | Low Power –Single capacitive sensor connected between a port and ground.
500kHz | High Speed/4 –Differential capacitive sensor connected between 2 ports with
the middle tap of the sensor connected to ground.
2,00MHz | High Speed –Single capacitive sensor connected between 2 ports.

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Conversion Duration
Displays the entire conversion duration per cycles for averaging and fake
measurements.
C_TRIG_SEL
Selects the source that triggers the start of a capacitance measurement
Continuous –Continuous measurement, self-triggering. Recommended when no
temperature measurement is made in parallel.
Read Triggered –Triggered by read out
Timer Triggered –Depending on the setting the ‘Conversion Time’. Generally
recommended setting →less prone to error conditions.
Timer Triggered (Stretched) –Depending on the setting the CONV_TIME. The
parameter is used as sequence period.
Pin triggered –Triggered by external Pin, selectable from option ext.Trigger-Pin
Opcode Triggered | Off –Started by SPI Command 0x8C
Continuous (exp.) –(not recommended)
Ext. Trigger-Pin
Used to select the pin to be used as the source of trigger for the capacitance
measurement.
NOTE: In the delivered EVA board, the pins DSP_IN0 and DSP_IN1 are part of the SPI
communication interface, hence only DSP_IN2 and DSP_IN3 selections are relevant.
Conversion Control
CONV_TIME
Sets the conversion time in multiples of twice the period of the low-frequency clock
Conversion Time
Displays the entire conversion time per measurement.
Measuring rate
Displays the frequency at which capacitive measurement data is transferred from the
DSP to the interface (SPI or I2C).

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1.2.1.4 RDC Page
Figure 11 RDC page
Options on ‘RDC’ page:
Temp.Sensor0
To select a thermistor connected to port PT0/REF for temperature measurement. This
could be e.g. an external PT1000.
Temp.Sensor1
To select a thermistor connected to port PT1 for temperature measurement.
Temp.Sensor2
To select either the internal aluminium (ALU) thermistor for temperature measurement.
Reference
To select either the internal Poly-Si thermistor or an external reference resistor at port
PT0/REF for temperature measurement.
Cycle Control
Precharge Time
Displays the precharge time. It depends on R_OLF_DIV.
Fullcharge Time
Displays the fullcharge time It depends on R_OLF_DIV.
Discharge Time
Set the discharge time. It depends on R_OLF_DIV.
R_AVRG
Set averaging for temperature measurement.

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R_FAKE
Set number of fake measurements per temperature measurement cycle.
Conversion Duration
Displays the entire conversion duration per cycles for averaging and fake
measurements.
Conversion Control
Temp. Trigger Select
Selects the source that triggers the start of a temperature measurement:
Off: Default setting when no temperature measurement is wanted. In this case, a
temperature measurement can still be started by SPI Command 0x8E.
OLF_CLK: Triggered by Low-frequency oscillator.
Pin-Triggered: Triggered by external Pin, selectable from option ext.Trigger-Pin
CDC asynchronous: Depending on the setting in the ‘T_TRIG_PREDIV’ counter on the
RDC page. The DSP is triggered by the RDC end of conversion. If RDC rate is less than
CDC rate the DSP is triggered directly from the CDC for inactive RDC conversions.
CDC synchronous: Depending on the setting in the ‘T_TRIG_PREDIV’ counter on the
RDC page. The DSP is triggered by the RDC end of conversion. Assuming that RDC
rate is less than the CDC rate, the inactive RDC conversions are replaced by a delay.
R_TRIG_PREDIV
For CDC and OLF options the RDC measure rate can be reduced by setting a divider.
Conversion Time
Displays the entire conversion time per measurement.
Measuring Rate
Displays the frequency at which capacitive measurement data is transferred from the
DSP to the interface (SPI or I2C).
Ext. Trigger-Pin
Used to select the pin to be used as the source of trigger for the capacitance
measurement.
NOTE: In the evaluation board, the pins DSP_IN0 and DSP_IN1 are part of the SPI
communication interface, hence only DSP_IN2 and DSP_IN3 selections can be used.

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3.1.2.1 PDM / PWM Page
Figure 12 PDM/PWM page
Options on ‘PDM / PWM’ page:
Clock Select
Selects the clock frequency to be used for the PWM/PDM generation.
Resolution
Resolution of the output in bits. This resolution also determines the pulsed output range.
Pulse Interface Select
Select the pulse interface –Pulse Width Modulated Output (PWM) or Pulse Density
Modulated (PDM) Output. Of the two, the PDM is the recommended interface.
With PWM option, 100 kHz clock and 10-bit resolution the resulting PWM output
frequency = (100 kHz / 1024) ~ 100 Hz.
Toggle Enable
activates toggle flip flop at Pulse Interface Output, especially for PDM to
create 1:1 duty factor
Pulse Select
Select the measurement result which has to be given out as pulsed output –any of the
capacitance or temperature measurement results.

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3.1.2.2 DSP/GPIO Page
Figure 13 DSP/GPIO page

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Options on ‘DSP/GPIO’ page:
DSP
DSP_SPEED
Select the DSP Speed.
Choose between Fastest, Fast, Slow and Slowest.
DSP_FF_IN
Pin mask for latching flip-flop activation (PG0 to PG3)
DSP_MOFLO_EN
Activates anti-bouncing filter in PG0 and PG1 lines
DSP_STARTONPIN
Not supported by standard firmware
The DSP can be started externally by a signal on a pin; these buttons select the pin that
has to be sensed for detecting the start signal.
DSP_START_EN
Mask for activating various trigger sources for starting the DSP
GPIO
PG_DIR_IN
To configure the ports PG0-PG3 as input (otherwise output)
PG_UP
To enable the internal pull up on the ports PG0-PG3
PG0_X_PG2
Possible only when the selected interface for communication is IIC. Interchange PortG0
with PortG2. This is useful when the Pulsed output is needed on Port PG0 instead of PG2.
PG1_X_PG3
Possible only when the selected interface for communication is IIC. Interchange PortG1
with PortG3. This is useful when the Pulsed output is needed on Port PG1 instead of PG3.
PG4_INTN_EN
Map the Interrupt output from chip, INTN to Port PG4.
This setting is useful for 24 pin QFN package, because the dedicated INTN pin is absent in
this version.
PG5_INTN_EN
Map the Interrupt output from chip, INTN to Port PG5.
This setting is useful for 24 pin QFN package, because the dedicated INTN pin is absent in
this version.