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VAMeter

SKU:K136

Description

VAMeter is a professional, programmable, high-precision power meter designed for accurate voltage and current measurements. Powered by the Stamp-S3 module, it features Wi-Fi connectivity and two cascaded INA226 current/voltage sensing circuits, delivering current detection resolutions of 2.5 µA and 250 µA. The measurement range supports 0-5 A and 5-24 V (1-24 V in isolation mode).

The device offers flexible power-supply options through the USB-C port or the Base terminal, with built-in power and signal isolation. A slide switch lets users choose between isolated measurements powered via USB and non-isolated measurements powered directly from the test source, meeting various application needs.

The included expansion BASE provides relay on/off control and a Grove port for secondary development. Additional features include OTA firmware upgrades and USB MSC/OTG support, allowing users to view and edit data and configuration files stored in the main controller’s file system from a PC.

M5Stack also supplies a free online data API for uploading test data to the EZData platform, enabling remote access and visualization and greatly simplifying IoT application development.

VAMeter is a highly practical and developer-friendly instrument, ideal for projects requiring precise current and voltage measurements, as well as for industrial automation, equipment monitoring, smart grid, and related fields.

Tutorial

This tutorial introduces usage examples of VAMeter.

Features

  • High-precision current detection (2.5 µA / 250 µA resolution switching)
  • Wide voltage input (5-24 V)
  • Cloud data display via EZData
  • PD input (no PD trigger built in)
  • Multiple power-supply methods (PD INPUT / Stamp-S3 / external terminal block)
  • Power and signal isolation
  • USB MSC/OTG support
  • Open-source hardware & software
  • Wireless OTA upgrade
  • Development Platform
    • UiFlow2
    • Arduino IDE
    • ESP-IDF
    • PlatformIO

Includes

  • 1 x VAMeter
  • 1 x VAMeter Base
  • 2 x 3.81-2P Terminal Block
  • 4 x Hanger (Small)

Applications

  • Industrial automation
  • Equipment monitoring
  • Power testing & analysis
  • IoT devices
  • Remote monitoring & data acquisition

Specifications

Specification Parameter
SoC ESP32S3FN8 @ Xtensa® 32-bit LX7 dual-core, up to 240 MHz
Power Measurement IC INA226
INA226 I²C Address Dual INA226 sensors: 0x40 / 0x41
Flash 8 MB Flash
Wi-Fi IEEE 802.11 b/g/n (2.4 GHz)
Display 1.3 inch @ 240 × 240 pixels
Display Driver ST7789
PD Input Power 5-24 V @ 0-5 A
Current Resolution 2.5 µA / 250 µA
Current Sampling Err Small current (1-100 mA): 1.01 %
Large current (100 mA-5 A): 0.94 %
µA-level current: 0.69 %
Voltage Error Measurement error: 0.11 %
Power Consumption Stamp-S3 USB powered: DC 5 V / 123.5 mA
PD INPUT: DC 5 V / 118 mA
DC 12 V / 66.8 mA
DC 24 V / 26 mA
PD OUTPUT Capability DC 24 V @ 3 A 68 ℃
DC 24 V @ 5 A 92 ℃
User Interface Rotary encoder switch, Reset button, Boot button, onboard buzzer
Relay DC 5 - 24 V @ 5 A
Operating Temp. 0 - 40 °C
Product Size 51.5 × 48.0 × 40.5 mm
Product Weight 43.4 g
Package Size 160.9 × 93.0 × 31.6 mm
Gross Weight 68.4 g

Learn

Download Mode

Download Mode
To enter download mode, press and hold the G0 button on VAMeter before power-on, then release it after powering up.
schematics

M5 EZData Cloud Platform Example

schematics

Schematics

VAMeter Internal Block Diagram

schematics

PinMap

VAMeter (INA226 & BUZZER)

Note
INA226 (0x40) and INA226 (0x41) are used for measurements at different resolutions and ranges.
ESP32S3FN8 G5 G6 G41 G40 G14
INA226 (0x40) FSDA FSCL ALERT1
INA226 (0x41) FSDA FSCL ALERT2
BUZZER BUZ_PWM

VAMeter Expansion Pins

ESP32S3FN8 G10 G9 G8 G42
Expansion EXT_G10 EXT_G9 EXT_G8 EXT_G42

VAMeter Base

ESP32S3FN8 G10
Relay GPIO10_REL

HY2.0-4P

HY2.0-4P Black Red Yellow White
PORT.CUSTOM GND 5V G8 G9

Model Size

module size

PCB

Datasheets

Softwares

Quick Start

ESP-IDF

Easyloader

Easyloader Download Note
VAMeter Firmware Easyloader download /

Other

Video

  • VAMeter Feature Introduction

Product Comparison

schematics