SLAA494B May   2011  – September 2023 MSP430AFE221 , MSP430AFE222 , MSP430AFE223 , MSP430AFE231 , MSP430AFE232 , MSP430AFE233 , MSP430AFE251 , MSP430AFE252 , MSP430AFE253

 

  1.   1
  2.   Implementation of a Single-Phase Electronic Watt-Hour Meter Using the MSP430AFE2xx
  3. 1 Trademarks
  4. 2 Introduction
  5. 3 Block Diagram
  6. 4 Hardware Implementation
    1. 4.1 Power Supply
      1. 4.1.1 Resistor Capacitor (RC) Power Supply
      2. 4.1.2 Switching-Based Power Supply
    2. 4.2 Analog Inputs
      1. 4.2.1 Voltage Inputs
      2. 4.2.2 Current Inputs
  7. 5 Software Implementation
    1. 5.1 Peripherals Setup
      1. 5.1.1 SD24 Setup
    2. 5.2 Foreground Process
      1. 5.2.1 Formulas
        1. 5.2.1.1 Voltage and Current
        2. 5.2.1.2 Power and Energy
    3. 5.3 The Background Process
      1. 5.3.1 Voltage and Current Signals
      2. 5.3.2 Phase Compensation
      3. 5.3.3 Frequency Measurement and Cycle Tracking
      4. 5.3.4 LED Pulse Generation
    4. 5.4 Energy Meter Configuration
  8. 6 Energy Meter Demo
    1. 6.1 EVM Overview
      1. 6.1.1 Connections to the Test Setup or AC Voltages
      2. 6.1.2 Power Supply Options
    2. 6.2 Loading the Example Code
      1. 6.2.1 Opening the Project
  9. 7 Results
    1. 7.1 Viewing Results on PC
    2. 7.2 Viewing Results During Debug
  10. 8 Important Notes
  11. 9 Schematics
  12. 10References
  13. 11Revision History

6.1.2 Power Supply Options

The EVM can be configured to operate with different sources for power specific to the MSP430AFE253 and the MSP430F6638. The various sources of power to the MSP430 devices are JTAG, mains voltage, and external power. Table 6-1 lists the header settings for the power options of the MSP430AFE253 only.

Table 6-1 Power Supply Selection for MSP430AFE253
Power OptionJTG_PWR1PWR1
JTAGJumper on [1-2]No jumper
Mains supplyNo jumperJumper on [1-2]
External powerNo jumperJumper on [1-2]

If JTAG debugging is necessary with external power is ON, the jumper on [2-3] on JTG_PWR1 must be placed in addition to the jumper on PWR1. External power can be provided directly between the DVCC1 and DGND1 headers.

When powered by the mains supply, the PWR1 header can also be treated as a current consumption header by placing an ammeter across it. Also, when powered via JTAG, the current consumption header is no longer PWR1; instead, the ammeter can be connected across [1-2] of header JTAG_PWR1.

Table 6-2 lists the header settings for the power options of the MSP430F6638 only.

Table 6-2 Power Supply Selection for MSP430F6638
Power OptionJTG_PWR2PWR2
JTAGJumper on [1-2]No jumper
Mains supplyNo jumperJumper on [1-2]
External powerNo jumperJumper on [2-3]

JTAG debugging is necessary with external power is ON. In addition, to jumper on PWR1, jumper on [2-3] on JTG_PWR1 must be placed. External power can be provided directly between DVCC2 and DGND2 headers. In addition for USB power option for the entire board, R15 must be populated and jumper be placed on PWR2 at position [2-3].

When powered by the mains supply PWR2 header can also be treated as a current consumption header by placing an ammeter across. Also, when powered via JTAG, the current consumption header will be no longer PWR2, instead the ammeter can be connected across [1-2] of header JTAG_PWR2.