LGT8F328P with USB

This board type comes with a USB-C connector and USB-to-Serial converter, making it trivial to connect the board to a PC and upload firmware.

Front Pin-Out

Back Pin-Out

Start with this board type for prototyping and development when frequently updating the firmware is a priority.

Once your firmware works, you may want to switch to the smaller Pro Mini-style board without Serial-to-USB circuitry. This gives you a smaller size and significantly lower power consumption.

Overview

This board is perfect for experimenting and prototyping. Connect the board via USB-C to your PC, and use the platform.io development environment to compile and upload Arduino code.

This is the platformio.ini configuration file for platform.io:

[env:LGT8F328P]
platform = lgt8f
board = LGT8F328P
framework = arduino
board_build.f_cpu = 8000000L   ; 16MHz internal clock
board_build.clock_source = 1   ; 1 = internal, 2 = external

upload_flags = 
    -u
    -V
    -D
upload_speed = 57600
monitor_dtr = 0
monitor_rts = 0

Power and Consumption

This board can be powered in three different ways:

The on-board voltage regulator stabilizes *only the 3.3V pin. The 5V pin – despite its label – happens to expose whatever voltage you externally apply.

Consumption

The total board power consumption is divided primarily among these main components:

• Microcontroller
• Status LED
• Serial-to-USB
• Voltage Regulator

Serial-to-USB

The on-board Serial-to-USB component requires considerable extra power:

Voltage Regulator

The LGT8F328P microcontroller can natively handle supply voltages in the exceptionally large range of 1.8 - 5.5 V, and in contrast to genuine Arduino Nanos, the supply voltage does not limit the MCU speed. So for many use cases, you wouldn’t need a voltage regulator for the microcontroller, especially when working with Lithium batteries.

However, the same may not be true for peripherals, and possibly you may want to run the board with even higher voltages. That’s why this type of board comes with an on-board AMS1117 voltage regulator.

Some board versions use a AMS1117-3.3 thus using a 3.3 V rail for peripherals. Other versions use a AMS1117-5 with a classic 5 V rail. Always verify the rail voltage so it fits your peripherals.

• Voltage Regulator Marking:
  Check whether the voltage regulator on your board has a readable marking.
• Measure Voltage:
  Measure the internal rail voltage between VCC and GND.

Conclusions

The Nano-style board version adds the USB-to-UART IC and its associated circuitry. Depending on the exact board revision, that can be CH340G, CH9340C, HT42B534, or another bridge. These chips themselves consume several milliamps, and some board designs fail to put the bridge properly into USB suspend when USB is disconnected. One documented LGT8F328P Nano variant has especially high consumption for exactly this reason.

This also explains something that otherwise looks odd: at 1 MHz, the Nano board still takes 22.8 mA, even though the corresponding Pro Mini needs only 7.3 mA. Reducing the CPU clock cannot eliminate the ~15 mA board-level overhead.

Slow Website?

This website is very fast, and pages should appear instantly. If this site is slow for you, then your routing may be messed up, and this issue does not only affect done.land, but potentially a few other websites and downloads as well. Here are simple steps to speed up your Internet experience and fix issues with slow websites and downloads..

Comments

Please do leave comments below. I am using utteran.ce, an open-source and ad-free light-weight commenting system.

  Show on Github    Submit Issue

^{_{(content created Sep 20, 2026)}}