First of all, the idea to build a power meter that can measure the efficiency of DC-DC converters is quite old though was constantly postponed. But now, when Russia strikes civilian infrastructure in my country (including power plants), and we use different battery-powered devices, voltage converters, and power banks a lot - it'll be really useful.

In the photo, you can see the main components that are required for the project:

• INA3221 board (updated version, as the first design used a single power source for each channel)
• 1.3" 240x240 IPS screen
• LILYGO® T8 V1.7.1 ESP32 Module (the board is far from ideal for the battery-powered device, but I have a few of them)
• Encoder
• Slide switch
• Screw terminals with 5mm pitch
• Li-ion battery
• USB type-C socket (optional)

After playing a bit with the components layout, I printed a prototype:

It revealed a few issues with the dimensions and that the sliding switch is missing. Here is the final (for now) model:

I'll print it in 2023)

A few words about the code. For me, it was always interesting to use LVGL in a real project (but I rarely build projects with a screen), so now it's time. Also, I'll use Arduino via PlatformIO and many things that FreeRTOS provides.