Hand Tool Anemometer — DIY Manual

A portable handheld solid-state anemometer built with a M5Stack DIAL, a WindQX solid-state anemometer sensor, a 3D-printed case, and a rechargeable battery.

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Table of Contents

1. Overview
2. Bill of Materials
3. 3D-Printed Case
4. Hardware Assembly
5. Programming with UIFlow 2.0
6. Usage
7. Calibration
8. Troubleshooting
9. License

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Overview

This project turns an M5Stack DIAL and a WindQX SA.01P solid-state anemometer into a compact, portable handheld wind-speed meter. Unlike traditional cup-anemometers, the WindQX sensor has no moving parts it measures wind speed and temperature using thermal technology, making it robust and maintenance-free.

The M5Stack DIAL provides:

• A round 1.28″ TFT display (240 × 240 px) for an analogue-gauge-style readout.
• A rotary encoder (EC11) to switch between display units and modes.
• An ESP32-S3 processor with built-in Wi-Fi and Bluetooth.
• A USB-C port and built-in battery (or external battery pack via Grove).

The program is written entirely with visual blocks in the UIFlow 2.0 IDE, making it accessible without prior text-based coding experience.

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Bill of Materials

#	Component	Qty	Notes	Picture
1	M5Stack DIAL	1	ESP32-S3, 1.28″ round display
2	WindQX SA.01P Solid-State Anemometer	1	5 V, I2C output, UART optional
3	3D-printed case	1	Files in 3d/
4	Li-Po rechargeable battery	1	3.7v 3400mAh 18650 Li-ion with PH1.25mm 2P
5	Grove cable 4-pin, 10 cm	1	HY2.0-4Pin for M5Stack Development Board
6	USB-C cable	1	Programming and charging

Tools required: soldering iron, resing 3D printer (or printing service).

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3D-Printed Case

The case is designed to hold the M5Stack DIAL in one hand with the WindQX sensor pointing forward. All design files are in the 3d/ directory.

Print settings: recommended 0.2 mm layer height, 20 % infill, PLA or PETG.

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Hardware Assembly

Step 1 — Prepare the M5Stack DIAL

1. Charge the Li-Po rechargeable battery before starting. You can use the M5Stack DIAL via USB-C as a charger.
2. Confirm the firmware version is UIFlow 2.x (hold the encoder button while powering on; the screen shows the current mode and firmware).
3. If needed, flash UIFlow 2.x firmware using the M5Burner tool.

Download the UIFlow firmware	Setup the firmware	Flash the firmaware

Step 2 — Connect the WindQX Sensor

The WindQX sensor communicates over I2C at address id 54. Using the i2c0 login interface at 100 KHz. Connect it to the M5Stack DIAL Grove Port A (bottom right connector) using a standard Grove cable:

Grove Pin	DIAL Pin	WindQX Wire
1 — White	SCL (15)	SCL
2 — Yellow	SDA (13)	SDA
3 — Red	5 V	VCC +
4 — Black	GND	GND -

⚠️ The WindQX sensor requires 5 V. The M5Stack DIAL Grove port provides 5 V on pin 3. Do not exceed this voltage.

The WindQX sensors come with a connector that is not a Grove connector, so it will need to be replaced. The simplest way is to cut it off and solder the wires so that it looks like this:

1	2	3

Step 3 — Install the Battery

The M5Stack DIAL has an internal JST PH 1.25mm connector for a Li-Po battery and includes a charge regulator. Insert the 3.7 V 500 mAh battery and secure it with the provided adhesive pad if your enclosure requires it.

1	2	3

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Programming with UIFlow 2.0

The firmware is a UIFlow 2.0 block program located in src/anemometer_dial.m5f2.

Loading the Program

1. Open UIFlow 2.0 in your browser (or the desktop app).
2. Connect the M5Stack DIAL via USB-C or Wi-Fi.

3. Create a new project	4. Click Import project from local file and select src/WindQX_Anemometer.m5f2

5. Select run or download	6. Setup the connection to burn the program

7. Click Project files (+) and select src/iconAlarm.png	Icon

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Program Logic (Block Overview)

The program is structured in three parts:

A. Initialisation (On Start)

[On Start]
  ├─ Init built-in hardware
  ├─ Init rotary encoder → built-in
  ├─ Set alarmHighSpeed → 20
  ├─ Set SA01_ADDR → 54
  ├─ Load page0
  ├─ Configure History chart
  │   ├─ Series name → speed
  │   ├─ Update mode → shift
  │   ├─ Point count → 10
  │   ├─ Y-axis min/max → 0 / 60
  │   └─ Point size → width 10, height 10
  ├─ Set last_min_ms → current ticks in milliseconds
  ├─ Set title text → "WindQX"
  ├─ Set dialWind current value → 20
  ├─ Set lblWind text → "20"
  ├─ Set kmh text → "km/h"
  ├─ Configure alarm selector
  │   ├─ Min → 0
  │   ├─ Max → 100
  │   └─ Value → alarmHighSpeed
  ├─ Set AlarmNumber text → alarmHighSpeed
  ├─ Turn AlarmLED off
  ├─ Set AlarmLED size → 0 x 0
  ├─ Set dialTemp current value → 0
  ├─ Set lblTemp text → "0"
  ├─ Set Celsius text → "C"
  └─ Init I2C bus → SCL 15, SDA 13, 100 kHz

B. Main Loop (Loop Forever)

[Loop Forever]
  ├─ If BtnA is holding
  │   └─ Turn off the device
  ├─ Read 4 bytes by I2C from SA01_ADDR → data
  ├─ Extract wind bytes
  │   ├─ rawWind1 ← data[1]
  │   └─ rawWind2 ← data[2]
  ├─ Calculate wind_kmh
  │   └─ wind_kmh = ((rawWind1 × 256) + rawWind2) ÷ 10
  ├─ Update wind display
  │   ├─ Set lblWind text → wind_kmh
  │   └─ Set dialWind value → rounded wind_kmh
  ├─ Extract temperature bytes
  │   ├─ rawTemp3 ← data[3]
  │   └─ rawTemp4 ← data[4]
  ├─ Calculate temp_c
  │   └─ temp_c = (((rawTemp3 × 256) + rawTemp4) ÷ 100) - 40
  ├─ Round temp_c to integer
  ├─ Update temperature display
  │   ├─ Set lblTemp text → temp_c
  │   └─ Set dialTemp value → temp_c
  ├─ If rotary encoder has rotated
  │   ├─ Change alarmHighSpeed by encoder increment
  │   ├─ If alarmHighSpeed > 100
  │   │   └─ Keep value unchanged
  │   ├─ Set AlarmSelector value → alarmHighSpeed
  │   └─ Set AlarmNumber text → alarmHighSpeed
  ├─ If wind_kmh > alarmHighSpeed
  │   ├─ Set AlarmLED size → 10 x 10
  │   ├─ Turn AlarmLED on
  │   └─ Repeat 3 times
  │       ├─ Speaker tone 1000 for 500 ms
  │       └─ Speaker tone 15000 for 500 ms
  ├─ Else
  │   ├─ Turn AlarmLED off
  │   └─ Set AlarmLED size → 0 x 0
  ├─ Set now_ms → current ticks in milliseconds
  ├─ If (now_ms - last_min_ms) > 10000
  │   ├─ Set last_min_ms → current ticks in milliseconds
  │   └─ Add rounded wind_kmh to History chart
  └─ Wait 250 ms

C. Encoder Interaction (On Encoder Rotate)

[When AlarmSelector value changed]
  ├─ Set AlarmNumber text → AlarmSelector value
  └─ Set alarmHighSpeed → AlarmSelector value

Usage

1. Power on — Short-press the encoder button. The DIAL logo appears and the device boots (~3 s).
2. Read wind speed — The gauge needle and numeric value update every 250 ms. If the wind speed > 0, the LED color of sensor turns into red.
3. Set alarm threshold a. Rotating the encoder clockwise to increase the value or anti-clockwise to reduce the value. b. By dragging the dot on the slider with your finger to the desired alarm value.
4. Alarm — If the current wind speed is greater than the selected alert threshold, the device will emit beeps and the speed icon will display a red dot.
5. Power off — Long-press the encoder button.

Display Layout

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Calibration

The WindQX sensor is factory-calibrated. For best results:

1. Point the sensor directly into the wind (0° incidence).
2. Hold the device at arm's length, away from body turbulence.
3. For field calibration against a reference anemometer, use the CALIBRATION_OFFSET constant at the top of the program (block: Set CALIBRATION_OFFSET to 0.0). A positive value adds to every reading; a negative value subtracts.

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Troubleshooting

Symptom	Possible cause	Fix
Display shows ---	No I2C data from sensor	Check wiring; confirm sensor is powered (5 V LED)
Wind speed always 0.0	Low battery power
Device won't power on	Battery depleted	Charge via USB-C for 1 hour before retrying
UIFlow can't find device	Wi-Fi not connected	Use USB-C connection or check Wi-Fi credentials in M5Burner

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License

This project is released under the MIT License.
© McOrts — contributions welcome via Pull Request.