Table of Contents So hello guys, welcome back to Gettobyte Once again. Todays blog is going to be on interfacing the Energy metering IC : HLW8012 which is manufactured by HLW Technology.On previous blogs we have developed the application driver   for W25Q SPI based flash memory’s, is time we are going to develop the Application driver for HLW8012. So first question that must come in your mind is that what is Energy Metering IC. Lets first Understand this term. What are Energy Metering Integrated Chips ? Before Understanding Energy metering IC’s their is one term that i would like to get familiar my viewers that is ASIC’s. ASIC’s are Application Specific Integrated Chips i.e. chips which are designed, developed and fabricated for particular applications.  Energy Metering IC’s are one of the ASIC’s. In this case the specific application is that of Electrical Energy Measurement. By the use and emergence of Energy Metering IC’s we can calculate the Electrical Energy parameters like RMS/Instantaneous Voltage, RMS/Instantaneous Current, Reactive/Active/Apparent Power, Energy Consumed, Power loss/dissipation, Power factor, Frequency digitally. Using this electrical Energy Measurements only our monthly electrical energy bill is calculated. These electrical energy parameters play very important role for monitoring and analyzing of Power consumption in our homes, offices, factories, city’s and all such infrastructures where their is use of electricity. These Ic’s are widely used in Energy Meters, Multifunction Meters, Smart Energy meters, Solar Energy control panels, Factory Automation Panels and etc. Energy metering IC’s are designed using the knowledge of ADC, Opamps, Low pass/High pass filters, use of Analog Electronics with Power Electronics, DSP(Digital Signal processing), Signal Conditioning circuits. All these circuits are designed inside the Energy Metering IC’s using VLSI/VHDL. That is where the concept of Application Specific comes in. So when reading the datasheet of Energy Metering IC’s some overview about these terms and terminologies would be beneficial for understanding the functioning of these IC’s. Voltage and current drive the world in every sense. Using these 2 parameters we can calculate all other electrical energy parameters be it reactive power, active power, energy, frequency, power factor and etc. Energy Metering IC’s primarily measures/senses only Voltage and Current by the use of Signal conditioning circuits, ADC, Opamps, Analog Electronics. Further these IC’s calculates all other Electrical energy parameters using DSP, Low pass/High pass filters and etc. All of these things are designed inside the Energy metering IC’s. Input voltage and current to these IC’s are fed depending upon the principal which we are using for sensing Voltage and current. After feeding the Input to these IC’s via one of the above principals, comes the role of above mentioned circuits/units which are designed inside the chips for their efficient functioning and digital accurate readings. Energy metering IC’s which are widely used are of The above listed metering IC’s and their development boards are very expensive, so for my use case i have found out some cheap/alternative Energy Metering IC’s, but their manufacturer are Chinese companies: STMicroelectronics Metering ICSTMP32/33/34 seriesClick HereTexas Instruments Metering ICsClick HereAnalog DevicesADE seriesClick HereNXP semiconductorsClick Here Previous Next HLW8012( the one we are using this blog) HLW8032 BLO937 PZEM-004T module  CS5460 bi-directional energy meter module This is the First string, Second string, Third string of the sentence. General Description of HLW8012 Energy Metering IC HLW8012 is a single phase energy metering IC, which is based on shunt resistor based principal. The HLW8012 module has on board 1 milli-ohm copper-manganese shunt resistor, which acts as a shunt resistor and used to sense the voltage and current. One of the biggest problem with IC, is its datasheet. The datasheet of this IC is in Chinese language, so likely it would be difficult to understand from it. The IC can measure the RMS Voltage, RMS Current, Active power and Outputs these reading digitally in the form of PWM signals. HLW8012 is a good choice for making small and hobbyist kind of projects which requires the measurement of AC electrical parameters. One such project/product that I found, is made on HLW8012. HLW8012 is inexpensive and good alternative to be used in comparison to  other expensive metering IC’s. The module of HLW8012 is very handy and easy to use. It has 4 input terminals: 2 terminals are connected with AC Load and other 2 terminals are connected with AC Power supply. HLW8012 Outputs the Readings of Voltage, Current and power via PWM signals of 50 percent duty cycle, Their are two pins in HLW8012 CF and CF1 which outputs the voltage, current and power readings in a digital PWM square signal, which host MCU can capture using Timer Input Capture mode. The readings are directly proportional to the Frequency of the PWM signal. Every modern MCU has Timer peripheral, which we can configure in Timer Input capture mode. In this mode Host MCU can capture the PWM signals from external world (here our external world is HLW8012). That’s how HLW8012 will communicate with the Host MCU. Features of HLW8012 Energy Metering IC Based on shunt resistor based principal. Can measure current upto 20Amps and Voltage upto 300 Volts Easy interface to Host MCU sends voltage, current and power readings digitally via PWM square signals. Needs +5 volt to operate the IC. Block Diagram of HLW8012 Metering IC PINOUT of the HLW8012 Energy metering IC Pin Number 1 Pin number 1 is VCC (Chip Select), which is used to operate the power the HLW8012 IC. Connect this pin to +5 Volts of the host MCU. Pin Number 2 & 3 Pin number 2 &3 are V1P/V1N, which are Current differential input pins. These pins are connected in parallel to the shunt resistor(See the application circuit below). This connection is already made on the Module of HLW8012. The maximum voltage that can be input to these pins are 43.75mV. Pin Number 4 Pin number 4 is V2P, which is Voltage differential input pin, this pin is connected to  input AC voltage via resistor network of 47k ohms Pin Number 5 Pin