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VAMeter

SKU: K136

Description

VAMeter is a professional programmable high-precision power meter, primarily used for high-accuracy voltage and current measurements. The product is based on the Stamp-S3 main control module, equipped with WiFi functionality, and features two INA226 current and voltage measurement circuits in series, offering current detection resolutions of 2.5uA and 250uA. The measurement range supports 0-5A and 5-24V (1-24V in isolated mode). The product offers flexible power supply options, supporting power input via USB-C or Base terminals, and includes built-in power and signal isolation. Users can toggle between isolated measurement with USB power supply and non-isolated measurement with direct power supply by flipping a switch, catering to different application needs. The included expansion BASE comes with relay control and Grove ports, facilitating secondary development. Additionally, the device supports OTA firmware updates, USB MSC/OTG functionality, allowing users to edit and view data and configuration files stored in the main control file system on a PC. M5 also provides a free online data API interface, enabling users to upload test data to the EZData platform for remote access and browsing, greatly simplifying IoT application development. VAMeter is a highly practical and developable instrument, especially suitable for engineering projects requiring precise current and voltage measurements, as well as industrial automation, equipment monitoring, smart grids, and more.

Tutorial

This tutorial will introduce you to the VA Meter device tutorial & quick start

Features

  • High-precision current detection (2.5uA/250uA resolution switching)
  • Wide voltage input (5-24V)
  • Cloud (EZData) data display
  • PD input (internal PD decoy not included)
  • Multiple power supply methods (PD INPUT/StampS3/external terminal)
  • Power and signal isolation
  • USB MSC/OTG functionality
  • Open-source hardware and software
  • Wireless OTA updates
  • Development Platform
    • UiFlow2
    • Arduino IDE
    • ESP-IDF
    • Platform.IO

Includes

  • 1 x VAMeter
  • 1 x VAMeter Base
  • 2 x 3.81-2P terminals
  • 4 x small brackets

Applications

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

Specifications

Specification Parameters
SoC ESP32S3FN8@Xtensa® 32-bit LX7 dual-core processor, up to 240 MHz
Power detection chip INA226
INA226 communication address Two detection chips INA226: 0x40/0x41
Flash 8MB Flash
Wi-Fi IEEE 802.11 b/g/n (2.4 GHz Wi-Fi)
Screen 1.3 Inch@ 240 x 240 Pixel
Screen driver ST7789
PD input power 5-24V@0-5A
Current detection resolution 2.5uA/250uA
Current sampling error Small current (1-100mA) sampling error: 1.01%
Large current (100mA-5A) sampling error: 0.94%
uA level current sampling error: 0.69%
Voltage sampling error Measurement error: 0.11%
Power consumption (factory firmware) STAMP_S3 USB power supply: DC5V/123.5mA
PD INPUT power supply: DC5V/118mA    DC12V/66.8mA    DC24V/26mA
PD OUTPUT output capability DC-24V@3A 68℃
DC-24V@5A 92℃
User interaction Rotary encoder switch, reset button, Boot button, and onboard buzzer
Relay DC 5 ~ 24V@5A
Operating temperature 0 ~ 40°C
Product dimensions 51.5 x 48.0 x 40.5mm
Product weight 43.4g
Package dimensions 160.9 x 93.0 x 31.6mm
Gross weight 68.4g

Learn

Download Mode
To enter download mode, hold the G0 button on the VAMeter before powering on, then release after power is applied.
schematics

M5 EZData Cloud Platform Example

schematics

Schematics

VAMeter Internal Circuit Logic Diagram

schematics

PinMap

VAMeter (INA226 & BUZZER)

Note
INA226(0x40) and INA226(0x41) are used for different resolutions and measurement ranges.
M5STAMPS3 G5 G6 G41 G40 G14
INA226(0x40) FSDA FSCL ALERT1
INA226(0x41) FSDA FSCL ALERT2
BUZZER BUZ_PWM

VAMeter Expansion Output Pins

STAMPS3 G10 G9 G8 G42
Expansion Pins EXT_G10 EXT_G9 EXT_G8 EXT_G42

VAMeter Base

STAMPS3 G10
Relay GPIO10_REL

Grove

STAMPS3 G9 G8 VCC GND
Grove GPIO9 GPIO8 SYS_5V FGND

Model Size

module size

PCB

Datasheets

Softwares

ESP-IDF

Easyloader

Easyloader Download Link Notes
VAMeter Firmware Easyloader download /

Video

  • VAMeter Feature Introduction

Product Comparison

schematics