Probe motor implementation by devasilmy · Pull Request #47 · HEATRobotics/EMBR-Bot

devasilmy · 2026-01-28T06:44:00Z

Summary

This PR implements the core control logic for the LMDCE421 Stepper Motor (Probe Motor). It establishes a hardware abstraction layer using a Factory Pattern, allowing the system to switch between a Modbus TCP-based hardware driver and a simulated motor environment. It also introduces the nav node, which manages autonomous probe deployment and retraction cycles during rover surveying.

Related Task

Closes Notion Task

Type of Change

🆕 Feature (Initial implementation of Probe Motor control)
🧹 Refactor (Abstraction of sensors into a Factory pattern)
🧾 Documentation Update (New documentation added: rpi-ip-setup-for-motor.md, probe-motor.md)
🐞 Bug Fix
🧰 Maintenance / Tooling

📄 Documentation

All of the following applicable documentation changes were added

How to connect the new device and wiring see
Links to external documentation on the device
Any other setup or important information (Configuration via sensors.json)
No documentation changes required

Requirements Updated

requirements.txt has been updated with pymodbus and pyserial.

🧪 Testing

1. Simulation Testing:

Configured sensors.json with "mode": "sim".
Executed ros2 launch embr embr_launch.py.
Verified that the nav node correctly waits for ProbeMotorFeedback and handles simulated deployment delays

2. Hardware Integration (Modbus TCP):

Configured sensors.json with "mode": "real".
Verified 32-bit register read/writes
Commands tested:

✅ Pre-Merge Checklist

PR started as a Draft
Linked to correct Notion Task
Branch includes updated documentation
Code reviewed by peer
Ready for final review by Software Lead
All tests and builds pass
Notion task updated to Ready for Review

🧾 Notes (Optional)

Concurrency: The probe_stepper_server node now utilizes a MultiThreadedExecutor and ReentrantCallbackGroup to prevent deadlocks during long-running motor movements.
Architecture: The nav.py script uses a dedicated thread for the survey loop to keep the main ROS2 executor responsive to incoming feedback messages.

…ity (feedback not implemented)

…ce for action-server 3. Included entry point for node

make probe-motor upto date with main

Added prerequisites for Raspberry Pi setup guide.

Expanded documentation for the Rover Probe Motor Control System, detailing system architecture, requirements, configuration, ROS2 interface, setup, logic flow, and troubleshooting steps.

update probe-motor

This ros2 node has been revised and added to src/embr/embr as probeMotor.py

mrichards03

I'll do a more thorough check when you mark the PR as ready for review and when I can test with the actual probe stepper. It looks good so far though! I've left a few comments. Also don't forget about adding python dependencies to the dependencies script for provisioning. I believe pymodbus should be added.

mrichards03 · 2026-01-30T03:35:47Z

    return SensorFactory.create(sensor_type, config)
+
+
+class StepperFactory:


This class seems almost identical to the SensorFactory class. Why can't the SensorFactory create the probe stepper motor object? What's the need for another factory?

I totally agree. I'll work on merging the 2 factories together.

mrichards03 · 2026-01-30T03:38:33Z

@@ -0,0 +1 @@
+int32 move_position


I don't think you need a custom message when the message just contains an int. Just label the topic as having message type int32.

Added power requirements for LMD Drive in the setup guide.

…r interface with Int32

2. Added parameter for motion_range, max_velocity, and acceleration. 3. Added parameter change value validation to ensure values are within range.

… to motion_range set in CONFIG.

Moved to probe-motor.md

Contents moved to probe-motor.md

…error

maisonJar-dev

Great stuff! Just a few miscellaneous fixes but otherwise good to go!

maisonJar-dev · 2026-04-03T19:52:39Z

+      "acceleration":  1000000,
+      "steps_per_distance": 51200,
+      "motion_range": 10
+


Suggested change

Co-authored-by: Maison <maison.personal03@gmail.com>

The action was a previous implementation that was supposed to be removed. The communication type is now changed to a topic.

Added installation command for pymodbus to the script.

Clarified documentation on write_registers function to specify Little-Endian format.

maisonJar-dev

Looks good!

devasilmy added 17 commits November 8, 2025 18:23

Created base package for the probe_stepper_communication

6737029

created node script for the drive with basic action-server functional…

5f19131

…ity (feedback not implemented)

custom action interface for Probe_stepper_node_operation action-server

0a78e4e

1. Update 'servo' reference to 'drive' 2. Included custom msg interfa…

37f4c95

…ce for action-server 3. Included entry point for node

Merge pull request #44 from HEATRobotics/main

5e2c42c

make probe-motor upto date with main

action interface name corrected to match syntax, updated references too

c2896f4

Updated a faulty reference

7c62850

Updated a faulty reference

7386a81

Updated a faulty reference

cb0f4cd

Updated faulty reference

eff6b93

Raspberry Pi IP setup guide for motor

1ef3a2c

Add prerequisites section to RPi IP setup guide

4ef3120

Added prerequisites for Raspberry Pi setup guide.

Add files via upload

4fe7244

probe motor documentation

c600dce

Expanded documentation for the Rover Probe Motor Control System, detailing system architecture, requirements, configuration, ROS2 interface, setup, logic flow, and troubleshooting steps.

Fix relative paths in probe-motor documentation

8b5ddc6

revised probe-motor node, implemented probe-motor base and factory

d65c30a

Merge pull request #46 from HEATRobotics/main

5016b70

update probe-motor

devasilmy requested a review from mrichards03 January 28, 2026 06:44

devasilmy closed this Jan 28, 2026

devasilmy reopened this Jan 28, 2026

Delete ros2_ws/src/probe_stepper_communication directory

6dfd271

This ros2 node has been revised and added to src/embr/embr as probeMotor.py

mrichards03 requested changes Jan 30, 2026

View reviewed changes

devasilmy and others added 8 commits February 2, 2026 11:04

Update LMD Drive power requirements in documentation

0244adb

Added power requirements for LMD Drive in the setup guide.

Changed 'stepper' reference to 'motor', replaced custom MoveProbeMoto…

53f531e

…r interface with Int32

merged probeStepperFactory into SensorFactory, optimised sensor bases

0840f58

updated code

37a1bef

1. Changed probeMotor abstract class to inherit Sensor base.

d296844

2. Added parameter for motion_range, max_velocity, and acceleration. 3. Added parameter change value validation to ensure values are within range.

added dummy fields to match the real sensors.json

6168a51

Handle the case where extend probe requested without distance; resort…

4289453

… to motion_range set in CONFIG.

Visual Breakdown of MODBUS/TCP

43c5ee2

devasilmy added 6 commits March 21, 2026 14:29

updated incorrect references

2949960

Revise probe-motor documentation for clarity and detail

a934b62

Update Static IP Setup link in probe-motor.md

61119fa

Added motor image

7b49939

Delete Documentation/2025/probe-motor-communication.md

d4de8b8

Moved to probe-motor.md

Delete Documentation/2025/rpi-ip-setup-for-motor.md

29f1c2c

Contents moved to probe-motor.md

devasilmy marked this pull request as ready for review April 1, 2026 20:55

devasilmy requested review from maisonJar-dev and mrichards03 April 1, 2026 20:55

Abdul added 2 commits April 3, 2026 20:37

added empty parameters to avoid dictionary to data object conversion …

0e07273

…error

fixed incorrect access of data class object as dictionary

5ee9ffd

maisonJar-dev reviewed Apr 4, 2026

View reviewed changes

devasilmy and others added 16 commits April 3, 2026 23:47

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Delete ros2_ws/src/msg_interface/action/ProbeStepperOperation.action

4cf90ec

The action was a previous implementation that was supposed to be removed. The communication type is now changed to a topic.

Add pymodbus installation to dependencies script

4921ba3

Added installation command for pymodbus to the script.

Update write_registers documentation for clarity

4bdb626

Clarified documentation on write_registers function to specify Little-Endian format.

Included breakdown of Little-Endian for read_holding_registers

1a6cbe5

maisonJar-dev reviewed Apr 4, 2026

View reviewed changes

Deleted inactive action message interface

7f89529

		return SensorFactory.create(sensor_type, config)


		class StepperFactory:

		@@ -0,0 +1 @@
		int32 move_position No newline at end of file

Conversation

devasilmy commented Jan 28, 2026 • edited by maisonJar-dev Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

Related Task

Type of Change

📄 Documentation

Requirements Updated

🧪 Testing

✅ Pre-Merge Checklist

🧾 Notes (Optional)

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devasilmy commented Jan 28, 2026 •

edited by maisonJar-dev

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