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@NiKiZe
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This is my documentation and projects for reverse enginering

Coltech EMT707CTL From Clas Ohlson artid: 36-2897

Some discussions I don't understand in Finnish

To open this one up you need a 3 pointed "Nintendo" screwdriver

Chips

  • LM7805 5Volt standard regulator
  • 0053 Rebranded ADE7753 with 3.579545MHz crystal
  • Atmel AT89S52 24AU with 12MHz crystal
    • Reads from EEPROM
    • communicates with ADE7753
    • Reads buttons
    • Sends LCD updates to PIC1621B
  • 24LC03 I2C EEPROM for storing cost, power usage and probably calibration data
  • PIC1621B - Only Used as LCD driver
    • Uses separate Reset, Clock and Data lines (10 bit?) from AT89S52

Headers

ISP for AT89S52

Name Description
CLK Program Clock
GND
MISO Program MISO
VCC 5 Volt
RST Reset
MOSI Program MOSI

CON Between CPU board(A) and Meter board(B)

Pin Name Description
1 VCC 5Volt from LM7805
2 GND
3 PWCHK Goes high when power is stable
4 CF ADE7753 CF Pin
5 ZERO Toggles with line freq. see ADE7753 ZX Pin
6 DIN SPI MOSI
7 DOUT SPI MISO
8 SCLK SPI Clock
9 CS SPI ADE7753 Select
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