Analog Devices EVAL-ADuCM355QSPZ, Руководство пользователя

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EVAL-ADuCM355QSPZ Evaluation Board UG-1308
Rev. A | Page 15 of 24
V
O
LT
AG
E
TIME
EXCITATION WAVEFORM
16
887
-02
0
Figure 26. Typical Chronoamperometric Voltage Stimulus Waveform
CURRE
NT
TIME
RESPONSE WAVEFORM
1
688
7-
1
20
Figure 27. Typical Chronoamperometric Current Response Waveform
In the ADuCM355 firmware development package, the M355_
ECSns_CapaTest project implements a chronoamperometric
measurement.
The
AD5940Main.c
file contains an
AD5940AMPStructInit ()function that modifies the main
measurement parameters.
For the following example, only CH0 is used and all default
values are used. The resistor star model is connected to P5, as
per the examples described in the Cyclic Voltammetry Example
section and the EIS Example section.
Load the project in the preferred IDE and open a terminal
program. Compile and build the project and load the code onto
the
ADuCM355 . Start the code execution and save the UART
data to a .csv file for processing.
The example code sends the following three arrays of results to
the UART at a 230,400 bps baud rate:

The first set of values includes the current
measurement results for the SE0 channel in μA.

The next set of values includes the voltage
measurement results for the SE0 channel in V.

The final set of values includes the voltage
measurement results for the RE0 channel in V.
–100
100
0
200
300
500
400
600
1
11
5
22
9
34
3
45
7
57
1
68
5
79
9
91
3
10
27
11
41
12
55
13
69
14
83
15
97
17
11
CU
RRE
NT
(
µ
A)
INDEX
16
887
-12
2
Figure 28. Output Data Using the M355_ECSns_Capatest Example with
Three 1 kΩ Resistors
DC CURRENT EXAMPLE
The dc current is a standard electrochemical measurement.
Depending on the sensor type, a bias voltage is applied between
the reference and sense electrodes. The current output on the
sense electrode is measured.
In the ADuCM355 firmware package, the M355_ECSns_
SingleWE project implements a dc current measurement on
an electrochemical cell connected to CH0. The measurement
parameters can be configured in the
AD5940AMPStructInit()
function in the
AD5940Main.c
file. For testing purposes, connect
the 1 kΩ resistor star network to P5. Set the Vzero firmware
parameter to 1100 mV, and set the SensorBias firmware
parameter to 500 mV to apply a 500 mV bias across the 1 kΩ
resistor network. Ensure that the EVAL-ADuCM355QSPZ is
powered on and that the debugger is connected to the PC. Then
open the project in the preferred IDE, and compile and run the
example application. Open a terminal program to view the
results. The output is the current measured through the SE0 pin
on P5 of the EVAL-ADuCM355QSPZ (see Figure 29).
168
87
-02
1
Figure 29. CH0 Output