Add documentation to GTU7Config struct

[Copilot]

The GTU7Config struct lacked documentation explaining its purpose and fields, particularly the Reader field used for test injection.

Changes

• Added struct-level documentation explaining GTU-7 GPS module configuration via NMEA-0183 serial protocol
• Documented Reader field as optional io.Reader for test injection, allowing unit tests to provide mock NMEA data without hardware
• Included usage examples for both production (serial port) and testing scenarios

Example

// Production usage
gps := NewGTU7(GTU7Config{
    Name: "my-gps",
    Serial: drivers.SerialConfig{Port: "/dev/ttyUSB0", Baud: 9600},
})

// Test usage
gps := NewGTU7(GTU7Config{
    Reader: strings.NewReader("$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47\n"),
})

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• go.googlesource.com
  • Triggering command: /update-job-proxy /update-job-proxy 482489/b089/ (dns block)
  • Triggering command: /update-job-proxy /update-job-proxy DROP 6-4b60b310-15ec-log.showsignature=false test -e CA.pem as /bin/test /opt/hostedtoolc/usr/bin/git ervars.go ache/go/1.24.11/add test -e d8c20fc0c90a8f71REDACTED ache/go/1.24.11/x64/pkg/tool/lin-e est 3842313/b248/_pk/usr/sbin/ip6tables rity.crt 3842313/b248=> test (dns block)
• gopkg.in
  • Triggering command: /update-job-proxy /update-job-proxy 482489/b089/ (dns block)
  • Triggering command: /update-job-proxy /update-job-proxy DROP 6-4b60b310-15ec-log.showsignature=false test -e CA.pem as /bin/test /opt/hostedtoolc/usr/bin/git ervars.go ache/go/1.24.11/add test -e d8c20fc0c90a8f71REDACTED ache/go/1.24.11/x64/pkg/tool/lin-e est 3842313/b248/_pk/usr/sbin/ip6tables rity.crt 3842313/b248=> test (dns block)
• periph.io
  • Triggering command: /update-job-proxy /update-job-proxy 482489/b089/ (dns block)
  • Triggering command: /update-job-proxy /update-job-proxy DROP 6-4b60b310-15ec-log.showsignature=false test -e CA.pem as /bin/test /opt/hostedtoolc/usr/bin/git ervars.go ache/go/1.24.11/add test -e d8c20fc0c90a8f71REDACTED ache/go/1.24.11/x64/pkg/tool/lin-e est 3842313/b248/_pk/usr/sbin/ip6tables rity.crt 3842313/b248=> test (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[Copilot]

Pull request overview

This PR adds comprehensive documentation to the GTU7Config struct, explaining how to configure a GTU-7 GPS module with NMEA-0183 serial protocol support. The documentation includes usage examples for both production (with serial port) and testing scenarios (with mock data injection).

Changes:

• Added struct-level documentation for GTU7Config explaining the GPS module configuration
• Documented the Reader field for test injection, enabling unit tests without hardware
• Minor formatting adjustments to vh400.go struct initialization (alignment only)

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
sensors/gtu7.go	Added comprehensive documentation for GTU7Config struct, including usage examples and Reader field documentation for test injection
sensors/vh400.go	Formatting alignment changes to Descriptor struct field initialization (no functional changes)

Comments suppressed due to low confidence (1)

sensors/gtu7.go:66

• The comment on line 62 "Buf sizes the out channel. Default 16." appears to be misplaced. This comment should be associated with the Buf field on line 63, but it's currently positioned immediately after the Reader field documentation (lines 58-61), which might cause confusion. The Reader field documentation should be placed directly above the Reader field declaration at line 66, or the Buf comment should be moved to line 63 to properly document the Buf field.

	// Reader is an optional io.Reader for test injection.
	// When non-nil, the driver reads NMEA sentences from Reader instead of opening
	// a serial port. This allows unit tests to provide mock NMEA data via strings.NewReader
	// or similar without requiring hardware.
	// Buf sizes the out channel. Default 16.
	Buf int

	// Test injection
	Reader io.Reader

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.