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User Manual for DIGILENT models including: HY3131, DMM Shield, 5 1 2 Digit Digital Multimeter, DMM Shield 5 1 2 Digit Digital Multimeter, Digit Digital Multimeter, Digital Multimeter, Multimeter
Digilent, Inc.
DIGILENT, INC. - RADIOMAG GmbH
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You are here:: Digilent Documentation / Reference / Add-ons / DMM Shield / DMM Shield Reference Manual
DMM Shield Reference Manual
Table of Contents
The DMM Shield is a 5 1/2 Digit digital multimeter, designed for use with Digilent microcontroller boards and FPGA boards that are equipped with the Arduino shield header, see Compatible Boards. The shield is built around the HY3131 module from Hycon Technology, which is an analog front end DMM dedicated chip. The device has 7 measurements functions (AC/DC Voltage, AC/DC Current, Resistance, Diode, Continuity) and is factory calibrated. It can be used out of the box with the compatible system boards. It is accessed through a custom SPI interface, using digital IO pins exposed in the DMM Shield connector.
Overview
Features
Full compatibility with Digilent System Boards featuring the Arduino Shield Provides 4 banana connectors for measurements(Volts/, COM, mAmps, Amps). Floating COM AC/DC voltage and current measurements Diode, continuity measurement/function Resistance measurement Supports SPI connection
DMM Shield Reference Manual
Overview Features HY3131 Features in Brief Compatible Boards
Specifications Power Functional Description
Connectors and Jumpers
Digital Pins Used for Communication
EEPROM Memory Measurement Scales Accuracy Calibration Procedure
2 Points Calibration for Resistance Scales
3 Points Calibration for DC
2 Points Calibration for AC Software Libraries Appendix: Pinout Tables
DMM Shield Connector Pinout
Banana Connector Interface
Power Connector Analog Connector Digital IO Connector About this Document Additional Information
HY3131 Features in Brief
Programmable multifunctional switch network High-resolution, high-speed - ADCs - for high conversion speed, resolution and accuracy Digital RMS circuit - the conversion result is processed by the high-speed calculation of the inner hardware to realize the digital RMS [reference: http://www.hycontek.com/wp-content/uploads/Description-HYCON-EN.pdf] Operational amplifier Multifunctional comparator Peak-Hold measurement circuit - to achieve higher accuracy Low-Pass filter - implements a third order LPF Supports SPI interface connection
Compatible Boards
The DMM Shield is hardware compatible with all Digilent boards that use the Arduino Shield connector, however, the libraries and out of box experience are written for the following boards:
Arty-Z7 uC32TM WF32TM Downloaded from Arrow.Mcoamx3. 2TM
Uno32TM Arduino Uno Arduino Due Arduino Mega
The DMMShield can be used with both 3.3V and 5V voltage levels existing on the Arduino boards.
Note: The pic32 library is written to target the uC32 micro-controller board. For all the other boards from the series, the pin-out might suffer modifications.
Specifications
Voltage and Power Parameters Power Supply Input Voltage Power Supply Input Voltage
Power Supply Current Consumption
Min
Typical
Max
Units
3.0
3.3
3.6
V
-
5.0
-
V
-
90
100
mA
Ranges AC Voltage DC Voltage AC/DC Current Resistances
Min
Max
-30
+30
V
-50
+50
V
-5
+5
A
50
50M
Accuracy: +/-0.1% on Voltage, Current and 500-5M Resistance measurements +/-1% on 50 and 50M Resistances measurements Resolution: 5 1/2 Digit Floating COM with on board isolated power supply Protections:
60V PTC for Voltage and resistances and uA 630mA fuse for mA rail 6.3A fuse for A rail
Communication: Custom SPI protocol
Power
DMM Shield is powered by the system board. It uses both 5V0 and 3V3 power supplies. The average consumption of the DMM Shield is 90mA. The DMM shield features on-board power supplies that are used to power the DMM core of the board. The 5V power supply is isolated in order to provide an isolated reference signal for measurements. There are more than one reference signals on the DMM Shield board:
GND - Ground for the non-isolated section. References all the signals and voltage rails in the non-isolated section such as 5V0 and 3V3 voltages from the system board, relay driver, flash memory VSS_ISO - Most negative voltage in the isolated section. It is the reference for isolated power supplies VCC5V0_ISO and VCC3V3_ISO as well for all the digital signals in the isolated section COM_ISO - Reference for the DMM measurement. All the measurements done with the DMM Shield will be referenced to COM_ISO signal, through COM connector, J2. The reference is leveled at 1.8V above VSS_ISO AGND_ISO - Reference for all the analog signals in the isolated section. It is connected to the COM_ISO through a 0 resistor
Functional Description
Connectors and Jumpers
The DMM Shield is equipped with the Arduino shield header that provides powering and communication between the DMM Sheild and system board. There are also 4 banana connectors that interface the DMM with the sources and devices that need to be measured.
Banana Connectors (J1-J4)
J1 (V/) - is used for measuring the AC/DC voltages, Resistances, Diode and Continuity. J2 (COM) - is the reference for all the measurements that can be done with the DMM Shield. COM signal is floating from all the other reference points from the board. J3 (500mA) - is used for measuring AC/DC currents up to 500mA. J4 (5A) - is used for measuring AC/DC currents up to 5A.
Arduino Shield Connector (J5-J9):
J5 - 1×2 Header - Digital pins J6 - 2×6 Header - Analog pins J7, J8 - 2×8 Headers - Digital pins J9 - 1×8 Header - Power pins Downloaded from ArroFwo.rcodmeta. iled usage of each pin please see the Pinout Table Appendix Pinout Table Appendix.
Jumpers: JP1 - Frequency Measurement - Not Implemented
Digital Pins Used for Communication
SPI Pins The DMM Shield supports SPI communication with both the DMM chip and the EEPROM chip. The hardware interface lines DataIn (DI), DataOut (DO) and Clock (CK) are shared between the two devices, and the Chip Select (CS) lines are separate, allowing the user to access either of them with fewer hardware resources used. The DMM chip is electrically separated from the rest of the circuitry, therefore the communication lines need to be isolated as well. The EEPROM CS line is active high, while the DMM CS line is active low. The reading sequence for SPI DMM communication is the one below:
The writing sequence for SPI DMM communication is the one below:
The timing for SPI DMM communication is the one below:
GPIO Pins
There are three GPIO pins used for Relay control: RLU, RLD, RLI. Depending on the type of measurement performed, the corresponding relay/s need to be triggered/commanded using a GPIO pin. The relays RLI, RLU, and RLD are controlled by three digital signals, IO2, IO3, and IO4, from the shield connector.
Scales
RLI
RLU
RLD
50M
0
0
1
5M
0
0
1
500k
0
0
1
50k
0
0
1
5k
0
0
1
500
0
0
1
50
0
0
1
50VDC
0
1
0
5VDC
0
1
0
500mVDC
0
0
1
50mVDC
0
0
1
50VAC
0
1
0
5VAC
0
1
0
500mVAC
0
0
1
50mVAC
0
0
1
Downloaded from Arrow.com.
5ADC
0
0
0
Scales 500mADC 50mADC
5mADC 500uADC
5AAC 500mAAC 50mAAC
5mAAC 500uAAC Continuity
Diode
RLI
RLU
0
0
0
0
1
0
1
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
RLD 0 0 0 0 0 0 0 0 0 1 1
In addition to configuring the GPIO pins, setting each scale assumes the configuration of some registers. The HY3131 chip provides 23 configurable registers.
Scales INTE R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R2A R2B R2C R2D R2E R2F 50M 0x00 0xC0 0xCF 0x17 0x93 0x85 0x00 0x00 0x55 0x55 0x00 0x00 0x08 0x00 0x00 0x80 0x86 5M 0x00 0xC0 0xCF 0x17 0x93 0x85 0x00 0x00 0x55 0x55 0x00 0x00 0x08 0x00 0x80 0x80 0x86 500k 0x00 0xC0 0xCF 0x17 0x93 0x85 0x00 0x00 0x55 0x55 0x00 0x00 0x08 0x00 0x08 0x80 0x86 50k 0x00 0xC0 0xCF 0x17 0x83 0x85 0x00 0x00 0x55 0x00 0x00 0x00 0x40 0x00 0x06 0x44 0x94 5k 0x00 0xC0 0xCF 0x17 0x83 0x85 0x00 0x00 0x55 0x00 0x00 0x00 0x40 0x60 0x00 0x44 0x94 500 0x00 0xC0 0xCF 0x17 0x83 0x35 0x00 0x00 0x55 0x00 0x00 0x00 0x40 0x06 0x00 0x44 0x94 50 0x00 0xC0 0xCF 0x17 0x83 0x35 0x01 0x00 0x55 0x00 0x00 0x00 0x40 0x06 0x00 0x44 0x94 50VDC 0x00 0x60 0x00 0x17 0x8B 0x01 0x11 0x00 0x55 0x31 0x00 0x22 0x00 0x00 0x09 0x28 0xA0 5VDC 0x00 0x60 0x00 0x17 0x8B 0x01 0x11 0x00 0x55 0x31 0x00 0x22 0x00 0x00 0x90 0x28 0xA0 500mVDC 0x00 0xC0 0x00 0x17 0x8B 0x85 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x90 50mVDC 0x00 0x00 0x00 0x17 0x8B 0x35 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x90 50VAC 0x00 0xF2 0xDD 0x07 0x03 0x52 0x10 0x80 0x25 0x31 0xF8 0x22 0x00 0x00 0x0D 0x28 0xA0 5VAC 0x00 0xF2 0xDD 0x07 0x03 0x52 0x10 0x80 0x25 0x31 0xF8 0x22 0x00 0x00 0xD0 0x88 0xA0 500mVAC 0x00 0x92 0xDD 0x07 0x03 0x52 0x10 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 50mVAC 0x00 0x52 0xDD 0x07 0x03 0x00 0x13 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 5ADC 0x00 0x00 0x00 0x17 0x8B 0x95 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x80 500mADC 0x00 0x00 0x00 0x17 0x8B 0x95 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x80 50mADC 0x00 0x00 0x00 0x17 0x8B 0x35 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x80 5mADC 0x00 0x00 0x00 0x17 0x8B 0x95 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x80 500uADC 0x00 0x00 0x00 0x17 0x8B 0x35 0x11 0x00 0x55 0x31 0x00 0x00 0x00 0x00 0x00 0x00 0x80 5AAC 0x00 0x52 0xDD 0x07 0x03 0x00 0x13 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 500mAAC 0x00 0x92 0xDD 0x07 0x03 0x52 0x10 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 50mAAC 0x00 0x52 0xDD 0x07 0x03 0x00 0x13 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 5mAAC 0x00 0x92 0xDD 0x07 0x03 0x52 0x10 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 500uAAC 0x00 0x52 0xDD 0x07 0x03 0x00 0x13 0x80 0x25 0x11 0xF8 0x00 0x00 0x00 0x00 0x00 0x90 Continuity 0x00 0x74 0xCF 0x17 0x83 0x35 0x10 0x00 0x55 0x00 0x00 0x00 0x00 0x0A 0x00 0x40 0x86 Diode 0x00 0xC0 0xCF 0x17 0x8B 0x8D 0x10 0x00 0x55 0x31 0x00 0x00 0x00 0x08 0x00 0x40 0x86
Downloaded fromFoArrmroowre.coinmfo.rmation please see the library documentation for each platform ZYNQ or Digilent Microcontroller boards.
EEPROM Memory
The DMM Shield is equipped with a non-volatile EEPROM memory chip from Microchip: 93LC66BT datasheet available from Microchip's website ), which has 512 bytes/256 words (4kbits) available space. The memory can be accessed over a custom SPI protocol, using digital IO pins exposed in the DMM Shield connector: CS_EEPROM (EEPROM SPI chip select), DO (SPI MISO), DI (SPI MOSI) and CLK (SPI CLK).
While the chip select line is specific to EEPROM module, the SPI lines (data and clock) are shared with the DMM device.
Note the data is written and read from memory using word format addressing, instead of byte: bytes 0-1 are written at address 0x00, bytes 23 are written at address 0x01, etc.
The EEPROM is used to store the following system information:
Section Content
Addresses (words)
Size
Factory calibration data
0x93 0xFF
109 words / 218 bytes
Serial Number
0x8C 0x92
7 words / 14 bytes
User calibration data
0x1F 0x8B
109 words / 218 bytes
Free Memory
0x00 0x1E
31 words / 62 bytes
Please consult the DMM Shield Library User Guide for more information about the EEPROM module usage and communication. For more details about Calibration process, read more on Calibration Procedure below.
Measurement Scales
DMM Shield comes with preset scales of measurement. They will indicate the maximum value that can be accurately measured with the device. Keep in mind that at low values the resolution is lower and different scales might give a more accurate result since the device is calibrated closer that value. Ex: for a 40k resistor is better to use the 50k scale instead of the 500k for a better resolution. There are 4 scales for voltages, 5 for current and 7 for resistances. Additionally, there are two extra scales for Diode and Continuity.
Scales
-
-
-
-
-
-
-
-
AC Voltage
50m
500m
5
30
-
-
-
V
DC Voltage
50m
500m
5
50
-
-
-
V
AC/DC Current
500u
5m
50m
500m
5
-
-
A
Resistances
50
500
5k
50k
500k
5M
50M
Diode
Continuity
The device comes factory calibrated for each scale. For more details about calibration please see the Calibration procedure below.
Accuracy
The accuracy of the DMM Shield is around 0.1% for AC/DC Currents and Voltages, 500-5M Resistances and within the scales 1% for 50 and 50M Resistances. For AC Current and Voltage we guarantee the 0.1% accuracy at 50/60Hz. Note that outrunning the end of a scale will increase the measurement error. The accuracy is computed in percentage as a difference between the reference value and the measured value, reported to full scale.
Let's consider $R_{F}, M_{F}$ as the reference and the measured value at full scale and $F_{S}$ the full scale. The accuracy is computed as follows:
$$Accuracy=\frac {R_{F} - M_{F}}{F_{S}} * 100\label{10}\tag{10}$$
Calibration Procedure
The DMMShield needs calibration before performing measurements and delivering correctly measured values to the user. This is due to errors introduced by the chip itself and on-board additional electronics. Calibration is the process of computing and applying correction coefficients to the measured values that allow precise measurements.
The process consists of computing an additive and a multiplicative coefficient for each scale.
Calibration is done by collecting pairs of reference value and measured value (RefVal, MsVal) in multiple points. The reference value is the value measured with an accurate instrument, considered to be the actual value to be measured by the DMMShield device. The measured value is the value reported by DMMShield hardware. When all these pairs are collected, the calibration coefficients are computed mainly using the difference between the reference and the measured values.
Depending on the scale, different types of calibration are performed, as detailed in the following chapters:
2 Points Calibration for Resistance Scales
This method applies to the Resistance scales. It collects the pairs (RefVal, MsVal) in two points: 0 point (short between probes), and full scale value.
Let's consider this pairs as being ($R_{0}$, $M_{0}$) and ($R_{F}$, $M_{F}$). The calibration coefficients are computed in the following manner: Downloaded from$$ACraroliwb_.c{MomU.LT}=\frac {R_{0} - R_{F}}{M_{0} - M_{F}} - 1\label{1}\tag{1}$$ $$Calib_{ADD}=(R_{0} - M_{0})(1 +
Calib_{MULT})\label{2}\tag{2}$$
The reference value for the short is considered to be 0: $R_{0} = 0$
The calibration coefficients are applied to the acquired value in the following manner: $$Value_{corrected}=(1 + Calib_{MULT})Value_{acquired} + Calib_{ADD}\label{3}\tag{3}$$
3 Points Calibration for DC
This method applies to the DC Voltage and DC Current scales. It collects the pairs (RefVal, MsVal) in three points: 0 point (short between probes for voltage and open for current), negative full scale value and positive full scale value. For example, for VoltageDC500m scale, the following points are used: 0 point (short between probes), -500mV, 500 mV.
Let's consider this pairs as being ($R_{0}$, $M_{0}$), ($R_{FN}$, $M_{FN}$) and ($R_{FP}$, $M_{FP}$). The calibration coefficients are computed in the following manner:
$$Calib_{MULT}=\frac {R_{FP} - R_{FN}}{M_{FP} - M_{FN}} - 1\label{4}\tag{4}$$ $$Calib_{ADD}=(R_{0} - M_{0})(1 + Calib_{MULT})\label{5}\tag{5}$$
The reference value for the zero calibration is considered to be 0: $R_{0} = 0$
The calibration coefficients are applied to the acquired value in the following manner: $$Value_{corrected}=(1 + Calib_{MULT})Value_{acquired} + Calib_{ADD}\label{6}\tag{6}$$
2 Points Calibration for AC
This method applies to the AC Voltage and AC Current scales. It collects the pairs (RefVal, MsVal) in two points: 0 point (short between probes for voltage and open for current) and full scale value. For example, for VoltageAC500m scale, the following points are used: 0 point (short between probes) and 500 mV.
Let's consider this pairs as being ($R_{0}$, $M_{0}$), ($R_{F}$, $M_{F}$). The calibration coefficients are computed in the following manner: $$Calib_{MULT}=\frac {R_{F}}{\sqrt{{M_{F}}^2 - {M_{0}}^2}} - 1\label{7}\tag{7}$$ $$Calib_{ADD}= M_{0}\label{8}\tag{8}$$
The reference value for the zero calibration is considered to be 0: $R_{0} = 0$
The calibration coefficients are applied to the acquired value in the following manner: $$Value_{corrected}=(1 + Calib_{MULT})\sqrt{| {Value_{acquired}}^2- {Calib_{ADD}}^2 |}\label{9}\tag{9}$$
Software Libraries
Digilent provides libraries to access DMM Shield functionality. The libraries were created to support ZYNQ plaform and Digilent PIC32 microcontroller boards. Both libraries come with a demo that allows the communication with the DMM Shield through UART. Functions as setting a scale and measure can be accessed by entering commands in the UART terminal emulator. Another demo shows how to access the memory left in the EEPROM by reading and writing 32 words. Documentation and downloads for these libraries can be found at the following locations:
ZYNQ PIC32 Arduino
Appendix: Pinout Tables
DMM Shield Connector Pinout
Banana Connector Interface
J1
J2
Voltage/
COM
J3 Current (mA)
J4 Current (A)
Power Connector
J9 Connector pin number
1 2 3 4 5 6 7 8 Downloaded from Arrow.com.
Arduino Shield Name NC 3V3 NC 3V3 5V0 GND GND VIN
Analog Connector
J6
Outer Row
Inner Row
Connector pin number
Arduino Shield Name
Connector pin number
Arduino Shield Name
1
A0
2
A6
3
A1
4
A7
5
A2
6
A8
7
A3
8
A9
9
A4
10
A10
11
A5
12
A11
Digital IO Connector
J7
Inner Row
Outer row
Connector pin number
Arduino Shield Name
Connector pin number
Arduino Shield Name
1
IO41
2
A
3
IO40
4
G
5
IO39
6
IO13/CLK
7
IO38
8
IO12/DI
9
IO37
10
IO11/DO
11
IO36
12
IO10/CS_DMM
13
IO35
14
IO9/CS_EEPROM
15
IO34
16
IO8
J8
Inner Row
Outer Row
Connector pin number
Arduino Shield Name
Connector pin number
Arduino Shield Name
1
IO33
2
IO7
3
IO32
4
IO6
5
IO31
6
IO5
7
IO30
8
IO4/RLD
9
IO29
10
IO3/RLU
11
IO28
12
IO2/RLI
13
IO27
14
IO1
15
IO26
16
IO0
About this Document
This reference manual applies to Revision C of the DMM Shield.
Additional Information
Arduino DMM Shield Library User Guide Arty Z7 DMM Shield Oled Demo User Guide Arty Z7-20 DMM Shield Webserver Demo User Guide PIC32 DMM Shield Library User Guide Zynq DMM Shield Library User Guide
Downloaded from Arrow.com.
doc, rm, dmmshield
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Downloaded from Arrow.com.