Power supply | Power detector -INA219

## Physical picture  Power-on effect--no page! No page! No page!  ## Principle introduction The main chip is INA219 (power detection chip)  INA219 supports I2C communication. It is connected to a sampling circuit. After the current flows through the sampling resistor, INA219 stores its data into registers. Use Arduino to read the registers in INA219 through I2C protocol, and then display the required data on the OLED screen through I2C. . Its principle block diagram is as follows:  ## Production process Recently I found some acrylic covers customized by tb before, so here are the works! Its structure is composed of PLA shell + motherboard + screen motherboard + acrylic cover. ###### Step1 The 2-in-1 print is separated into two boards. Be careful not to scratch the bottom board. It should be displayed outside.  ###### Step2 Solder the motherboard, making sure not to solder the pin headers above the chip. After soldering, connect the downloader to download the program and solder the pin header. The LED will light up after normal power on.  ###### Step3 To weld the screen motherboard, first solder the screen pin header, align the pin header with the PCB with the screen side (be sure to pay attention, otherwise it will not be soldered), and the solder joints after welding can be scraped off with a knife. There are three pin header holders in front of the upper and lower boards.  Next, weld the four pads of the screen to the screen PCB and add more tin.  ###### Step4 Weld the upper and lower plates and put them into the 3D shell (it's a little difficult to snap here, mainly because you want both the left and right sides to be embedded in the 3D shell), and then snap the cover in. It's more difficult to snap here, so snap one side first. Another corner is stuck, and the last corner works wonders, and it is very strong after being stuck.  ## Video display