Single Phase Low-Cost Energy Meter
IMS System Lab & Technical Marketing
Single Phase Low-Cost E-Meter
Overview
Solution Features
Products Overview
Technical Specification
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Overview
What is
Low Cost Single Phase Energy Meter solution based on
STPM01(STPM10) for energy measurement
STM8L152 low power 8-Bit MCU
Target Application
Energy Meter low cost
Home Appliance Self-Monitoring
Smart Grid application
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Single Phase Energy Meter solution
Low Cost E-Meter System based on STPM01 and STM8L152
Key features
Supports IEC 61036:1996 + A1: 2000
H/W LCD driver by STM8 directly
MCU in-built RTC calendar (data/time)
External EEPROM data Log:
Metering parameters,
Tamper Event
Multi anti-tamper detection:
Earth,
Reverse,
Neutral,
Case Tamper
Magnetic Interference
Dual Battery:
Coin Battery used in halt mode to keep RTC running
Rechargeable battery to power backup if the main
power supply is off.
Auto Calibration of Board (240V, 10A)
Communication: IrDA with serialIO PC GUI
4VA power consumption for voltage circuit
1VA power consumption for current circuit
Meter Features:
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Accuracy : Class 1.0
Nominal Voltage : 240V
Nominal Current : 5A (ITYP)
Maximum Current : 45A (IMAX)
Power Frequency Range : 45 Hz to 65 Hz
Sensor : Current Transformer (CT) and Shunt
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Single Phase Energy Meter solution
Key products:
STM8L152C6T6
8bits Low Power MCU
STPM01FTR
Energy meter (STPM10 compatible)
M24C32-RMN6TP
32 Kbit serial I²C bus EEPROM
BAT30KFILM
Schottky diodes
TL431AIZT
Programmable voltage reference
Order code : STEVAL-IPE012V1
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Low-Cost Single Phase E-Meter
Products overview
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STM8L152 low power 8bit MCU
Key features
STM8 Core
16MHz Fcpu  16CISC MIPS
Harvard Architecture;
3-stage pipeline
-40 to 125°C
1.8V to 3.6V range (down to 1.65V)
LCD: up to 4x28 segments w/ step-up converter
Up to 32K Flash, 2K SRAM, 1K data EEPROM
4 Ultra Low Power modes
+/- 1% Internal RC accuracy
Low power consumption:
0,4µA Halt
1µA Active Halt (with RTC)
Safe Reset System (POR/PDR, BOR, PVD)
All I/Os are high sink/source (20mA)
USART, SPI, I2C, ADC 12bit, Timer
This Solution is based on STM8L152C6T6:
32Kb Flash,2Kb RAM, 1KbEEPROM
LQFP 48pins
ADC 25x12bit, 1XSPI, 1XUSART
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STPM01 Energy Meter
TSSOP20
Measurement:
Active, Reactive, Apparent Energies, Vrms,
Irms, Frequency
Sensors:
Rogowski, Current Transformer, Shunt.
Tamper Proof:
2 current channels available
Accuracy:
0.1% in 1:1000 range
Support IEC61036 and ANSI C12.1
CALIBRATION
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Very short calibration time
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No ripple in the active energy
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Separated for voltage and current
OTP
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Prevention of tamper by changing calibration data
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No need of loading the configuration data from
MCU at startup
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Perfect data retention in harsh environment
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M24C32-R
32 Kbit serial I²C bus EEPROM
Supports the I2C bus modes: 100/400KHz
Single supply voltages: – 1.8 V to 5.5 V
Write Control input
Byte and Page Write
Random and Sequential Read modes
Self-timed programming cycle
Automatic address incrementing
Enhanced ESD/latch-up protection
More than 1 Million write cycles
More than 40-year data retention
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TL431AIZ: PROGRAMMABLE SHUNT VOLTAGE REFERENCE
ADJUSTABLE OUTPUT VOLTAGE :2.5 to 36V
SINK CURRENT CAPABILITY : 1 to 100mA
TYPICAL OUTPUT IMPEDANCE : 0.22W
1% AND 2% VOLTAGE PRECISION
-40°C, +105°C
BAT30 : Small signal Schotky diodes
IF = 300 mA, VRRM = 30 V, C (typ) = 14 pF, Tj (max) = 150° C
Very low conduction losses
Negligible switching losses
Low forward and reverse recovery times
Extremely fast switching
Surface mount device
Low capacitance diode
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E-Meter Single Phase Low-Cost
Technical Specification
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Dual Battery Management Circuit
Vdd
RESET
50mAh
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EXT2
EXT1
Coin Cell Battery - CR2032 (3V, 225mAh) : is used when the main power is off
Trickle charge Battery - VL2330 (3V, 50mAh) : is a rechargeable battery that can be
used for IrDA and to show on LCD the parameters when there isn’t main power pushing
the button
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Current Sensing
CT1: Current Transformer to do the
current sensing on the Phase
SHUNT: current sensing on the Neutral
CT2: The second current transformer is
not available on the evaluation
board (but ready to) and it’s used
as anti-tamper
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PC GUI
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PC-GUI used for setting real date and time
PC-GUI for testing protocol IEC 62056-21 mode – C using SCI (Serial Communication
Interface) of STM8L device (TDO, RDI) without IrDA ENDEC of STM8
STM8L has inbuilt IrDA interface
IrDA can be disabled by a single bit only, so STM8L can work in SCI mode as well as IrDA
mode
Reply sent by the tariff
device
Request
Message
Even parity is
selected
Baud Rate set
at 300bps
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STEVAL-IPE012V1 Evaluation Kit Package
Hardware content
STEVAL – IPE012V1 evaluation board
PC Software:
SerialIO GUI for IRDA Communication Testing
Documentation:
User Manual
Technical and Marketing Presentation
Schematic
BOM
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References
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STM8L152xx Datasheet/Reference Manual
AN3147: STM8L family power management
STPM01 Datasheet
AN2167: Using the STPM01 with a shunt current sensor
TL431 Datasheet
BAT30 Series Datasheet
IEC 62056-21 IrDA Protocol Mode C
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