Add Brother QL-810W label printer automation with AprilTags

.github/copilot-instructions.md

@@ -3,9 +3,27 @@
 - Start with minimal, lean implementations focused on proof-of-concept
 - Avoid creating new files until asked
 - Avoid implementing things from scratch
-- Avoid defensive error handling for hypothetical failures
+- Avoid defensive error handling for hypothetical situations
+  For example, rather than using:
+  ```python
+  ...
+  try:
+      import some_package
+  except:
+      print("some_package not available")
+      exit(1)
+  ...
+  ```
+  Instead, allow errors to bubble up naturally so you can address directly and reactively rather than being overly proactive
+  ```python
+  ...
+  import some_package
+  ...
+
+  ```
+  > `ModuleNotFoundError: No module named 'package_name'`
 - Use print statements and logging sparingly, unless asked
-- Avoid light wrappers and custom classes, unless asked
+- Avoid creating functions and classes, until asked
 - Avoid `if __name__ == "__main__"` patterns in package code, unless asked
   For example, rather than using:
   ```python
@@ -24,6 +42,7 @@
 - Skip unit tests unless explicitly requested
 - Follow patterns in CONTRIBUTING.md when present
 - Prefer writing Python if no language specified
+- For complex code changes, use your Serena MCP tools (e.g., `find_symbol`, `find_referencing_symbols`, and `insert_after_symbol`) for symbol-based code editing instead of always relying on regex for code modifications
 
 ## Git Operations
 
@@ -32,16 +51,19 @@
 
 ## External Resources
 
-- Validate and access link content using available MCP tools (Playwright and/or Perplexity)
+- Validate and access link content using your available MCP tools (Playwright and/or Perplexity)
 - Search GitHub for relevant open-source alternatives to commercial tools
-- Prioritize official package documentation over inferred usage by using Context7 MCP tool
+- Always utilize official package documentation via e.g., your Context7 MCP tool
 
 ## Communication Style
 
-- Use minimal emoji and special symbols
+- Use emoji and special symbols sparingly, if at all
 - Prioritize clarity and brevity in responses
 - Ask clarifying questions when needed
-- Don't infer requirements or create workarounds unless asked
+- Don't infer requirements or create workarounds unless asked. For example, instead of taking a fallback approach such as:
+  > Let me take a different approach - I'll create a simpler standalone demo that shows the concept without needing external dependencies
+  You should instead try additional ways to get the real dependencies installed. If you can't get it installed, update `.github/workflows/copilot-setup-steps.yml` with code that will pre-install it into your environment and then report back immediately with something like:
+  > After trying <command A> with <error message A>, <command B> with <error message B>, <command C> with <error message C>, ... <command Z> with <error message Z>, I was unable to install external dependencies. Per user's custom instructions, I will report back immediately. I will also provide useful links or web search keywords that will help the user debug and troubleshoot the installation failures.
 - Put documentation content in comment replies, not separate files, unless asked
 - Comments should not leave a trace of the development process
 - Avoid sycophancy, favor objectiveness
@@ -59,3 +81,6 @@
 - Include plots directly in your comment reply via `![image name](https://github.com/<user/org>/<repo>/blob/<shortened-commit-hash>/<filename>?raw=true)`. Truncate the commit hash to the first 7 characters only. For example, `https://github.com/AccelerationConsortium/evaluation-metrics/blob/52754e7/scripts/bo_benchmarks/demonstrations/branin_campaign_demonstration_results.png?raw=true`. For provenance, ensure you use the shortened (7-character) commit hash, not the branch name
 - If you mention files in your comment reply, add direct hyperlinks based on the shortened (7-character) commit hash
 - Use the following environment secrets: `HIVEMQ_HOST`, `HIVEMQ_USERNAME`, and `HIVEMQ_PASSWORD` for testing. Never echo or expose these, even in your logs
+
+## Repo-specific
+- IMPORTANT: run `conda activate ac-dev-lab` in your terminal before running any code (e.g., installing packages, running scripts, etc.). Alternatively, use the full path to `pip` or `python` within the `ac-dev-lab` environment

.gitignore

@@ -72,3 +72,5 @@ src/ac_training_lab/apriltag_demo/tag25_09_00000.png
 src/ac_training_lab/apriltag_demo/tag36_11_00000.png
 src/ac_training_lab/apriltag_demo/tag49_12_00000.png
 scripts/playwright/sem-open-close/chat.json
+src/ac_training_lab/label_printer/ql810w_ql820nwb_use_ug_06.pdf
+src/ac_training_lab/label_printer/ql820nwb_810w_useng_qsg_d017p7001_03.pdf

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 ### Added
+- Brother QL-810W label printer automation with AprilTags in `src/ac_training_lab/label_printer/` including MWE print script and Gradio web app with MQTT integration.
 - Support for both `rpicam-vid` (Raspberry Pi OS Trixie) and `libcamera-vid` (Raspberry Pi OS Bookworm) camera commands in `src/ac_training_lab/picam/device.py` to ensure compatibility across different OS versions.
 - Comprehensive Unit Operations section in `docs/index.md` documenting all available capabilities including dispensing, synthesis, characterization, and robotics operations.
 - Expanded Training Workflows section in `docs/index.md` with 10 educational workflows including RGB/RYB color matching, titration, yeast growth optimization, vision-enabled 3D printing optimization, microscopy image stitching, and AprilTag robot path planning.

src/ac_training_lab/label_printer/README.md

@@ -0,0 +1,123 @@
+# Brother QL-810W Label Printer Automation with AprilTags
+
+This module integrates with the repository's existing AprilTag resources rather than reimplementing tag generation or detection. See the apriltag_demo notebook and the cobot280pi utility for examples and helpers:
+
+- apriltag_demo notebook: src/ac_training_lab/apriltag_demo/apriltag_demo.ipynb (also runnable in Colab)
+- Simulated tag generator: src/ac_training_lab/cobot280pi/_scripts/pose_2025/generate_test_apriltag.py
+
+A lightweight helper script generate_apriltag.py is provided here for quick tag image generation and testing.
+## Hardware
+
+- **Printer**: Brother QL-810W (wireless label printer)
+- **Labels**: DK-2251 (black/red on white) or DK-4205 (removable, black on white)
+
+## Setup
+
+### 1. Install brother_ql
+
+```bash
+pip install brother_ql Pillow
+```
+
+### 2. Find printer
+
+For USB connection:
+```bash
+brother_ql discover
+```
+
+For network connection, use the printer's IP address:
+```
+tcp://192.168.1.XXX:9100
+```
+
+### 3. Disable Editor Lite mode
+
+If your printer has "Editor Lite" mode enabled, disable it by holding the button until the LED turns off. This is required for USB printing.
+
+### 4. Test print
+
+```bash
+export BROTHER_QL_PRINTER=tcp://192.168.1.XXX:9100
+export BROTHER_QL_MODEL=QL-810W
+brother_ql print -l 62 test_image.png
+```
+
+## Files
+
+- `mwe_print.py` - Minimal working example for sending a print command
+- `app.py` - Gradio web app for AprilTag printing with MQTT integration
+
+## Usage
+
+### MWE (Minimum Working Example)
+
+Configure environment variables and run:
+```bash
+export BROTHER_QL_PRINTER=tcp://192.168.1.XXX:9100
+export BROTHER_QL_MODEL=QL-810W
+export BROTHER_QL_LABEL=62
+python mwe_print.py
+```
+
+### Gradio App
+
+Configure MQTT credentials and run:
+```bash
+export HIVEMQ_HOST=your-broker.hivemq.cloud
+export HIVEMQ_USERNAME=your-username
+export HIVEMQ_PASSWORD=your-password
+python app.py
+```
+
+The Gradio app provides:
+- AprilTag generation with configurable tag family and ID
+- Print preview before sending to printer
+- MQTT integration for remote printing via HiveMQ
+
+## Troubleshooting
+
+### Raspberry Pi Setup
+
+The brother_ql library communicates directly with the printer, bypassing CUPS drivers. This is especially useful on Raspberry Pi where Brother's official i386 drivers are incompatible with ARM architecture.
+
+For USB on Linux, ensure proper permissions:
+```bash
+sudo usermod -a -G lp $USER
+```
+
+Or set up udev rules for the printer.
+
+### Backend Options
+
+- `pyusb` - Cross-platform USB (requires libusb)
+- `network` - TCP/IP for WiFi-enabled printers
+- `linux_kernel` - Uses /dev/usb/lp0 on Linux
+
+## Windows-Specific Setup (Prototyping/Testing)
+
+For testing and prototyping on Windows with USB connection:
+
+1. Install Brother drivers from the [official site](https://support.brother.com/g/b/downloadtop.aspx?c=us&lang=en&prod=lpql810weus) in advance
+1. Connect the Brother QL-810W via USB and ensure it's recognized by Windows.
+1. Disable Editor Lite mode: Hold the power button until the LED turns off (this mode prevents USB access for third-party libraries).
+1. Download Zadig from [https://zadig.akeo.ie/](https://zadig.akeo.ie/).
+1. Run Zadig as administrator.
+1. Select `Options` > `List All Devices`.
+1. Select the Brother QL-810W printer from the device list.
+1. Choose "libusb-win32" from the driver dropdown.
+1. Click "Install Driver" (or "Replace Driver").
+1. Restart your computer if necessary.
+
+This replaces the default Brother USB driver with libusb, allowing `brother_ql` to access the printer directly. For production use, switch to Raspberry Pi or network mode, as USB on Windows requires this manual driver replacement.
+
+## Related Issues
+
+- [ac-dev-lab #70](https://github.com/AccelerationConsortium/ac-dev-lab/issues/70) - Set up QL810WC label printer automation with AprilTags
+- [echem-cell #4](https://github.com/AccelerationConsortium/echem-cell/issues/4) - Electrocatalyst experiment equipment
+- [brother_ql #162](https://github.com/pklaus/brother_ql/issues/162) - Brother QL-810W Printer Not Printing on Raspberry Pi
+
+## References
+
+- [brother_ql documentation](https://github.com/pklaus/brother_ql)
+- [Brother QL-810W manual](https://support.brother.com/g/b/manualtop.aspx?c=ca&lang=en&prod=lpql810weus)