RELEASE_NOTES_1.8.10 - Alteriom/painlessMesh GitHub Wiki

Release Notes: v1.8.10

Release Date: November 18, 2025
Type: Patch Release (Bug Fix)

🎯 Overview

Version 1.8.10 is a focused patch release that fixes a critical bridge discovery issue where newly connected nodes were not reliably receiving bridge status information. This release improves the reliability of bridge-to-node communication in mesh networks.

🐛 Bug Fixes

Bridge Status Discovery - Direct Messaging

Issue: Newly connected nodes were not reliably receiving bridge status broadcasts, causing delays or failures in bridge discovery.

Root Cause Analysis:

Broadcast messages (routing=2) were not reaching newly connected nodes consistently
Time synchronization (NTP) operations were interfering with bridge discovery timing
Broadcast routing tables may not be fully established immediately after a node connects to the mesh
This led to nodes reporting "No primary bridge available" despite bridges being active

Solution Implemented:

Changed bridge status delivery mechanism from broadcast to direct single message
Bridge now sends status directly to newly connected nodes using sendSingle() (routing=1)
Minimal 500ms delay added for connection stability before sending status
Direct targeted delivery ensures the message reaches the new node reliably
Time sync operations no longer interfere with critical bridge discovery

Technical Details:

File Modified: src/arduino/wifi.hpp
Location: Line ~809 in initBridgeStatusBroadcast()
Change: Modified newConnectionCallback to use sendSingle(nodeId, ...) instead of sendBroadcast(...)
Routing Mode: Changed from routing=2 (broadcast) to routing=1 (single destination)

Impact:

✅ Nodes discover bridges immediately (within 500ms) after connecting
✅ Eliminates "No primary bridge available" errors for newly connected nodes
✅ More reliable mesh network initialization
✅ Better handling of nodes joining/rejoining the mesh
✅ Reduced dependency on broadcast routing table convergence

Backward Compatibility:

✅ No API changes
✅ Internal delivery mechanism improved
✅ All existing code continues to work without modification
✅ No breaking changes to bridge status packet format

Related Issues:

Resolves GitHub issue #135 "The latest fix does not work"

📦 What's Included

Core Changes

Bridge Discovery: Enhanced reliability for newly connected nodes
Message Delivery: Direct messaging replaces broadcast for critical status updates
Connection Stability: Added minimal delay for connection stabilization

Files Modified

src/arduino/wifi.hpp - Bridge status delivery mechanism
library.properties - Version update to 1.8.10
library.json - Version update to 1.8.10
package.json - Version update to 1.8.10
src/painlessMesh.h - Header version and date update
src/AlteriomPainlessMesh.h - Version defines update
CHANGELOG.md - Release entry added

🚀 Upgrade Guide

Installation

Arduino Library Manager:

Search for "Alteriom PainlessMesh" and update to v1.8.10

PlatformIO:

lib_deps = alteriom/AlteriomPainlessMesh@^1.8.10

NPM:

npm install @alteriom/[email protected]

Migration from v1.8.9

No changes required! This is a drop-in replacement for v1.8.9.

✅ All existing bridge code works unchanged
✅ All existing node code works unchanged
✅ No API modifications
✅ No configuration changes needed

Simply update the library version and redeploy.

🧪 Testing Recommendations

After upgrading to v1.8.10, test these scenarios:

1. New Node Connection Test

// Expected behavior:
// - Node connects to mesh
// - Receives bridge status within 500ms
// - No "No primary bridge available" errors

2. Bridge Discovery Test

// Expected behavior:
// - Multiple nodes connecting simultaneously
// - All nodes discover bridge reliably
// - Fast discovery regardless of NTP sync activity

3. Bridge Failover Test

// Expected behavior:
// - Bridge disconnects
// - New bridge elected
// - All nodes discover new bridge within 500ms

4. Network Rejoin Test

// Expected behavior:
// - Node loses connection and reconnects
// - Bridge status received immediately on rejoin
// - No discovery delays

🎯 Recommendations

Who Should Upgrade

Immediate Upgrade Recommended:

✅ Systems with frequent node connections/disconnections
✅ Networks experiencing bridge discovery delays
✅ Deployments with NTP time synchronization enabled
✅ Multi-bridge mesh networks
✅ Production systems requiring fast startup

Can Upgrade at Convenience:

Networks with stable connections and infrequent joins
Single-bridge setups without time sync
Development/testing environments

Deployment Strategy

Low-Risk Deployment:

Test in development environment first
Deploy to one bridge node
Monitor for 24 hours
Roll out to remaining nodes

Zero-Downtime Deployment:

Bridge nodes can be updated one at a time
Regular nodes can be updated in batches
No mesh network restart required

📊 Performance Characteristics

Resource Usage

Memory Impact: Negligible (no additional allocations)
CPU Impact: Minimal (one additional sendSingle() per connection)
Network Traffic: Slightly reduced (targeted delivery vs broadcast)

Timing Improvements

Before v1.8.10: Bridge discovery could take up to 30 seconds (periodic broadcast interval)
After v1.8.10: Bridge discovery within 500ms of connection

Network Efficiency

Broadcast Method: Message sent to all nodes (even if not needed)
Direct Method: Message sent only to newly connected node (more efficient)

🔍 Known Issues

None

This release has no known issues. The fix has been tested and validated.

Reporting Issues

If you encounter any problems with v1.8.10, please report them:

GitHub Issues: https://github.com/Alteriom/painlessMesh/issues
Include: Library version, platform (ESP32/ESP8266), and detailed description
Attach: Serial logs and minimal reproduction code if possible

🙏 Acknowledgments

Special thanks to the community members who reported and helped diagnose the bridge discovery issue, particularly:

GitHub user who reported issue #135

📚 Additional Resources

Documentation: https://alteriom.github.io/painlessMesh/
API Reference: https://alteriom.github.io/painlessMesh/#/api/doxygen
Examples: https://alteriom.github.io/painlessMesh/#/tutorials/basic-examples
Bridge Failover Guide: examples/bridge_failover/README.md
Changelog: CHANGELOG.md
Release Guide: RELEASE_GUIDE.md

🔜 Coming in Future Releases

Stay tuned for upcoming features:

Enhanced bridge load balancing
Advanced mesh diagnostics
Additional monitoring packages
Performance optimizations

Released: November 18, 2025
Version: 1.8.10
Type: Patch (Bug Fix)
Compatibility: 100% backward compatible with v1.8.9