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Precision motion control
While HomeGenie excels at smart home automation, its flexible architecture extends powerfully into the realm of robotics and mechatronics. Controlling physical movement with precision is key to these applications, from simple automated tasks to complex robotic systems. HomeGenie Mini, equipped with the appropriate firmware, provides an accessible platform for controlling servo and stepper motors – the building blocks of robotic motion. This capability opens up possibilities ranging from hobbyist projects and interactive toys to more sophisticated applications in automation and prototyping.
The smart-motor firmware for HomeGenie Mini
At the heart of controlling motors with HomeGenie Mini is the versatile smart-motor firmware. Designed primarily for ESP8266/ESP32-based devices, this firmware is specifically engineered to interface with and manage:
- Servo Motors: Standard hobby servos used for precise angular positioning (e.g., robotic joints, camera panning/tilting).
- Stepper Motors: Motors that move in discrete steps, often used with driver boards (like ULN2003 or A4988) for repeatable linear or rotational motion (e.g., 3D printers, precise actuators).
When flashed with the smart-motor firmware, your HomeGenie Mini device becomes a dedicated motor controller, exposing standard interfaces accessible through the HomeGenie ecosystem.
Key features & configuration
- Multiple Motor Support: Control up to 8 motors (servo or stepper, depending on board pins) simultaneously.
- Configuration Options: The firmware allows setting parameters like operational angle range, positioning speed, acceleration (for soft motion start/stop), and maximum steps for continuous rotation servos via specific API commands or module features.
- Normalized Control: The primary
Control.LevelAPI command accepts a normalized position value (from 0.00 to 1.00), representing the position within the configured range. This simplifies automation logic, allowing complex movements to be implemented using mathematical transformations, event triggers, or sequences. - System Integration: Controlled motors appear as modules within the HomeGenie Panel app and HomeGenie Server, ready for status monitoring and automation.
For the robotic arm animations shown in the videos on this page, no code was written. Instead, the Visual Program Editor in HomeGenie Server was used.
Common applications of the smart-motor firmware include:
- blinds Automated blinds and shutters.
- speed_camera Pan-and-tilt camera mounts.
- precision_manufacturing Robotic arms and grippers.
- robot_2 Animatronics and kinetic art.
- manufacturing Automated actuators for various tasks.
Getting started: building a 3D-printed Robotic Arm
Like other HomeGenie Mini devices, getting started with the smart-motor firmware is straightforward. This guide focuses on a practical example: building a small, 3D-printed robotic arm equipped with four common MG90S servo motors (180-degree rotation) and controlled by an ESP32 running the smart-motor firmware.
Firmware upload and motors calibration
First, flash the firmware using the Firmware Upload form found on this page. Select the smart-motor profile suitable for your ESP32 board and configure it to use 4 servo motors, assigning the correct GPIO pins for each servo's signal line.
(Tip): It is highly recommended to perform the initial Wi-Fi connection and servo calibration before fully assembling the Robot Arm. After flashing, connect the ESP32 to your servos (see the Connecting the servo motors section below for wiring details) and power it up. Use HomeGenie Panel or HomeGenie Server to connect the device to Wi-Fi and then command each servo to its center position (50% or 0.5 level). This pre-centering makes the subsequent mechanical assembly much easier and ensures correct alignment.
Printing the robot parts
Next, 3D print the mechanical components. You'll need a 3D printer and suitable filament (PLA or PETG are good choices).
Download the 3MF files for the robotic arm components from the Project Files section below.
All parts are designed to fit on a small build plate (e.g., Bambu Lab A1-mini). Printing typically takes around 2 hours 45 minutes with a 0.4mm nozzle and 0.20mm layer height. Ensure your printer is well-calibrated for dimensional accuracy.
Assembling all parts
Once the parts are printed and the servos are pre-centered (see Calibration step above), you can assemble the arm.
1. Gather Hardware:
Besides the printed parts, you'll need:
- 4x MG90S (or similar size) Servo Motors.
- Servo horns and horn screws (usually included with the servos).
- 10x M2 12mm and 10x M2 10mm screws
- Small Phillips head screwdriver.
2. Assembly Process:
The following sections detail the assembly of the main sub-components. Refer to the images for visual guidance.
Robot Arm - Gripper assembly
The process involves preparing the finger components with screws, inserting the gears and levers, closing the finger assemblies, mounting them onto the gripper base while aligning gears, inserting the servo motor into its cover, attaching the drive gear to the servo, mounting the cover/motor assembly onto the base, and finally securing the motor cover lid.
Follow the image sequence below:
Robot Arm - Main body assembly
The process involves placing the two servos into the housing halves, routing all three servo cables (two from this segment, one from the gripper) neatly, closing the housing, attaching the servo horns, inserting nuts for the connection points, and finally attaching this segment to the gripper assembly.
Follow the image sequence below:
Robot Arm: Base stand and final assembly
This final assembly section covers attaching the main arm structure (gripper and main body) to the rotating base stand, which houses the fourth servo motor responsible for the arm's rotation.
The process involves assembling the base itself by mounting the servo motor and securing it with a bracket, then aligning the completed arm assembly with the base and fastening the main pivot points.
Connecting the servo motors
With the arm assembled, connect the servo motors to your ESP32 board running the smart-motor firmware. Pay close attention to the wiring:
- Signal Pins: Connect the signal wire of each servo (often yellow, orange, or white) to the specific GPIO pins you configured when flashing the
smart-motorfirmware. - Power (VCC / 5V): Connect the VCC wire (usually red) of all four servos to a 5V pin on your ESP32 board.
- Ground (GND): Connect the ground wire (usually brown or black) of all four servos to a GND pin on the ESP32 board.
Important - Power Stability: While some ESP32 boards can adequately power four low-power micro-servos like the MG90S directly from their 5V output (if the board has a strong power source), servo motors can cause voltage fluctuations. To ensure stable operation, it is highly recommended to add power supply capacitors.
- Capacitor Placement: Solder one or two capacitors (e.g., 100-1000µF electrolytic plus optionally 0.1µF ceramic) across the main 5V and GND lines feeding the servos, close to the connection points.
- Testing: Based on testing with 4x MG90S servos, strategically placed capacitors have proven sufficient for stable operation when powered via the ESP32's 5V output pin. However, if you experience issues (resets, jitter), using a separate 5V power supply (2-3A rating) dedicated to the servos (with common ground to ESP32) is the most robust solution.
You can use a breadboard for temporary connections, but a dedicated PCB shield offers a cleaner setup.
A simple shield can facilitate connections and provide convenient locations for soldering the stabilizing capacitors.
Once wired and powered, the device should connect to Wi-Fi and appear in the HomeGenie Panel app, ready for control and automation via HomeGenie Server.
Project files download
3d printed Robot Arm
Robot Arm 3MF download REV. 1
Note: The Robot Arm design is based on a freely available model, remixed slightly for MG90S servos, M2 screws and for faster printing with a 0.20mm layer height. You can find the original SG90 Robot Arm by ChipCode on Printables.
Smart Light project files by G-Labs licensed under CC BY-NC 4.0
Create this device now! 🪄
Connect your ESP32/ESP8266 microcontroller to your computer via USB, select your firmware version, and click "Create device" to upload the HomeGenie Mini firmware.
1. Select device type
2. Select firmware flavor
3. Let the magic happen!
Installing firmware directly from this page works only in browsers with Web Serial API enabled.
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See the Device setup page for further information about configuring a HomeGenie Mini device.
Modules and API
In addition to the common Device API, this device implements the following modules and API.
S<n> module
Represents and controls the servo motor with address S<n> (<n> ::= '1' ... '8').
Domain / Address
Automation.Components/S<n>
(e.g. "Automation.HomeGenie/S1")
Properties
Status.LevelStatus.ColorHsbStatus.ErrorMotor.Type
("Servo" | "ServoEncoder" | "Stepper")Motor.Type.Servo.AngleMin
(default0)Motor.Type.Servo.AngleMax
(default180)Motor.Type.Servo.AngleSpeed
(1-10, default10)Motor.Type.ServoEncoder.Speed
(1-10, default10)Motor.Type.ServoEncoder.Steps
(max steps - configurable via calibration)Motor.Type.ServoEncoder.Calibrate
(calibration status)
Commands
Control.Open
(same as "Control.On")Control.Close
(same as "Control.Off")Control.Level/<level>
(0-100)Control.ColorHsb/<h>,<s>,<b>,<tansition_ms>Motor.Calibrate
(same as "Shutter.Calibrate")
