ams AG PCap04 User manual
PCap04 Standard Board
ams Eval Kit Manual
Page 2
[v1-02] 2017-Oct-20
Document Feedback
Content Guide
1Introduction .......................................................................................................................... 3
2Quick Start Guide................................................................................................................. 5
2.1 Install the Software............................................................................................................... 5
2.2 Install the Hardware: ............................................................................................................ 5
2.3 Quick Start for Initial Measurements.................................................................................... 6
3Hardware Description........................................................................................................... 9
3.1 Connecting Capacitors and Resistors.................................................................................. 9
3.2 Hardware Architecture ......................................................................................................... 9
3.2.1 PCAP04 BOARD.................................................................................................................. 9
3.2.2 Temperature Measurement ............................................................................................... 10
3.2.3 Pulse Code Generation...................................................................................................... 12
3.2.4 Motherboard....................................................................................................................... 12
4Software Description .......................................................................................................... 13
4.1 Initialization ........................................................................................................................ 13
4.2 Graphical User Interface .................................................................................................... 13
4.2.1 Front Panel......................................................................................................................... 13
4.2.2 Front Panel Menus............................................................................................................. 26
4.2.3 Special Windows................................................................................................................ 30
4.2.4 Linearize............................................................................................................................. 37
4.2.5 Assembler .......................................................................................................................... 42
4.3 Scaling Results .................................................................................................................. 42
4.4 Scaling PDM Output........................................................................................................... 44
5Schematics, Layers and BOM ........................................................................................... 45
6Ordering & Contact Information ......................................................................................... 49
7Copyrights & Disclaimer..................................................................................................... 50
8Revision Information .......................................................................................................... 51
PCap04 Standard Board
ams Eval Kit Manual
Page 3
[v1-02] 2017-Oct-20
Document Feedback
1 Introduction
The PCAP04-EVA-KIT evaluation system provides a complete system for generally evaluating the
PCapØ4 IC. It is supplied with a main board, a plug-in board, a Windows based evaluation
software, assembler software and the PICOPROG V3.0 programming device. The PCapØ4
evaluation board is connected to the PC‘s USB interface through the PICOPROG V3.0
programming device. The previous generation PICOPROG V2.0 programming device may also be
used with the PCAP04-EVA-KIT.
Figure 1: Kit Content
1 & 2
3
4
5
6
Pos.
Item
Comment
1
PCapØ1-MB
Motherboard
2
PCapØ4-EVA-BOARD
Plug-in board based on PCapØ4 in QFN24
package
3
PICOPROG V3.0
Programmer and interface box
4
USB cable
Connects PICOPROG V3.0 to PC
5
High density DSUB15 cable
Connecting Evaluation board to programmer
(optionally)
6
Wall power supply unit
9 V
The evaluation kit offers user-friendly operation of the PCapØ4 single-chip solution for capacitance
measurement. This kit can be used to evaluate the capacitance measurement, temperature
measurement and the pulse generation capabilities of the PCapØ4 chip. The kit also includes a CD-
PCap04 Standard Board
ams Eval Kit Manual
Page 5
[v1-02] 2017-Oct-20
Document Feedback
2 Quick Start Guide
In this section, we described how to set up quickly the PCAP04-EVA-KIT and establish basic
operation and make measurements.
2.1 Install 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.
Unzip the package to the desired directory.
Open “setup.exe” from the unzipped directory.
Follow the instructions on the screen.
2.2 Install the Hardware:
Install the software before
proceeding with this step!
Connect your computer with the
PICOPROG V3.0 using USB
cable.
Connect PICOPROG V3.0 and the
evaluation kit motherboard using
the DB15 interfaces
Mount the plug-in board on the
corresponding socket on the
motherboard.
Set the power supply unit to 7.5 V
output.
Connect the motherboard to
power via the power supply unit.
The green LED on the EVA kit
motherboard should be on.
Figure 2: Connected PCAP04-EVA-KIT
PCap04 Standard Board
ams Eval Kit Manual
Page 6
[v1-02] 2017-Oct-20
Document Feedback
2.3 Quick Start for Initial Measurements
From the “Start” menu, go to “All Programs” and then to the “acam” directory. Double click the
“PCap04 Frontpanel” icon to begin execution of the evaluation kit software. The following screen
should appear:
Figure 3: Setup page
Click the “Verify Interface” Button to confirm communication with PICOPROG V3.0 is working:
Figure 4: Verify Message
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.
PCap04 Standard Board
ams Eval Kit Manual
Page 7
[v1-02] 2017-Oct-20
Document Feedback
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 5: CDC Frontend page at the start
PCap04 Standard Board
ams Eval Kit Manual
Page 8
[v1-02] 2017-Oct-20
Document Feedback
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 6: CDC Frontend page in use
The C1 and C2 values should be continually updating but remain within a reasonably small
standard deviation as shown.
At this point if the above steps have been successfully completed basic operation of the EVA kit
should be achieved. The following sections provide a detailed description of the hardware and
software for advanced operation.
PCap04 Standard Board
ams Eval Kit Manual
Page 9
[v1-02] 2017-Oct-20
Document Feedback
3 Hardware Description
3.1 Connecting Capacitors and Resistors
This evaluation kit can be used for evaluating capacitance measurement by connecting capacitive
sensors. Further, it can be used for evaluating temperature measurement by connecting external
temperature sensitive resistors or for generating quasi analog voltage (pulse width/density
modulated) that is dependent on the sensor connected to the system.
Depending on the purpose of evaluation, a modification has to be made to the same plug-in board.
Following is a picture of the Mother board with the plug-in board.
Figure 7: The evaluation kit’s motherboard and plug-in board
The following sections describe the modifications for each application in detail.
3.2 Hardware Architecture
3.2.1 PCAP04 BOARD
For the purpose of evaluating the capacitance measurement using PCapØ4, the 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. 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 PCapØ4 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.
PCap04 Standard Board
ams Eval Kit Manual
Page 10
[v1-02] 2017-Oct-20
Document Feedback
Figure 8: 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 ends 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 kΩworks well. See section 3 of the PCapØ4 data sheet on how to select the value of
the internal discharge resistor.
3.2.2 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 PCapØ4 chip.
Figure 9 Temperature sensor connection pads
A
C
B
D
A
PCap04 Standard Board
ams Eval Kit Manual
Page 11
[v1-02] 2017-Oct-20
Document Feedback
Pos.
Item
Comment
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.
PCap04 Standard Board
ams Eval Kit Manual
Page 12
[v1-02] 2017-Oct-20
Document Feedback
3.2.3 Pulse Code Generation
Any of the capacitance or temperature measurement results from the PCapØ4 chip can be given
out as a pulse width modulated or pulse density modulated signal. This output can be filtered to
generate an analog output signal that can be used for further controlling.
These pulse width or pulse density codes can be generated at Ports PG0, PG1, PG2 or PG3 (in
block A). Since ports PG0 and PG1 are used for the SPI Interface in the board, the hardware allows
to get a valid pulse width/density modulated signal on PG2 or PG3. However, when I2C
communication mode is used the pulsed signals can be optionally obtained on the ports PG0 and
PG1.
Figure 10 General purpose interface ports PG0 to PG3 in block A
3.2.4 Motherboard
The motherboard connects to the PICOPROG V3.0 programmer. It serves the various power
options. It can be powered via wall plug supply (B), the voltage being set from 1.8 V to 4.5 V by
jumpers (C). Further, it supports a battery power option (D). The power options are switchable via
jumper (E). Power present is indicated by a green LED.
There is a jumper ‘Current’ on the mother board (F). The current consumption of the PCapØ4 chip
during operation can be directly measured from these jumper terminals.
All interface signals and general purpose I/O signals can be monitored by means of a separate
jumper in block A.
E
F
C
B
A
D
PCap04 Standard Board
ams Eval Kit Manual
Page 13
[v1-02] 2017-Oct-20
Document Feedback
4 Software Description
4.1 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 V3.0 programmer 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’.
4.2 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.
4.2.1 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.
PCap04 Standard Board
ams Eval Kit Manual
Page 14
[v1-02] 2017-Oct-20
Document Feedback
4.2.1.1 Setup Page
Figure 11 Setup page
Options on ‘Setup’ page:
Select Device
Select the PICOCAP device which you use.
<PCap04v0> means silicon version “Z”
<PCap04v1> means release silicon version “v1”
Read Device
Version from Chip
Reads the device version from chip
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.
PCap04 Standard Board
ams Eval Kit Manual
Page 15
[v1-02] 2017-Oct-20
Document Feedback
Verify Interface
When everything is in order, then pressing this button will indicate the release
version number of the software and of the 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
principal it shows the content of the read registers. The content itself depends on the firmware.
Figure 1-16 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).
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.’
PCap04 Standard Board
ams Eval Kit Manual
Page 17
[v1-02] 2017-Oct-20
Document Feedback
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)
PCap04 Standard Board
ams Eval Kit Manual
Page 18
[v1-02] 2017-Oct-20
Document Feedback
4.2.1.3 CDC Page
Figure 13 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.
PCap04 Standard Board
ams Eval Kit Manual
Page 19
[v1-02] 2017-Oct-20
Document Feedback
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.
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).
PCap04 Standard Board
ams Eval Kit Manual
Page 20
[v1-02] 2017-Oct-20
Document Feedback
4.2.1.4 RDC Page
Figure 14 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 aluminum (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.
This manual suits for next models
1
Table of contents
