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

Quick Start

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