📡 Reachy Mini Network Setup

🚨 CRITICAL REQUIREMENT

Your PC and Reachy MUST be on the EXACT SAME SUBNET to communicate. Even networks with similar names (like "HomeWiFi-2.4G" and "HomeWiFi-5G") are often different subnets and WILL NOT WORK!

🎯 Network Scenarios

✅ Scenario 1: WILL WORK

PC: Connected to "HomeWiFi-5G" (192.168.1.100)
Reachy: Connected to "HomeWiFi-5G" (192.168.1.110)
✓ Same network name, same subnet (192.168.1.x)

❌ Scenario 2: WON'T WORK

PC: Connected to "HomeWiFi-5G" (192.168.1.100)
Reachy: Connected to "HomeWiFi-2.4G" (192.168.0.110)
✗ Different subnets (192.168.1.x vs 192.168.0.x)

❌ Scenario 3: GUEST NETWORK ISOLATION

PC: Connected to "HomeWiFi-Main" (192.168.1.100)
Reachy: Connected to "HomeWiFi-Guest" (192.168.3.110)
✗ Guest networks are isolated from main network

❌ Scenario 4: VPN ACTIVE

PC: VPN Active (10.8.0.100)
Reachy: Local Network (192.168.1.110)
✗ VPN creates different network space

🔍 How to Verify Your Network

Step 1: Check Your Mac's Network

# See which WiFi network you're on
networksetup -getairportnetwork en0
# Output: Current Wi-Fi Network: HomeWiFi-5G

# Check your IP address
ifconfig en0 | grep inet
# Output: inet 192.168.1.100 netmask 0xffffff00

Step 2: Test Reachy Connection

# Try to ping Reachy
ping reachy-mini.local

# If that fails, check ARP table
arp -a | grep -i reachy

# Run network scanner
python3 /Users/erikbethke/Desktop/robotics/robots/reachy/find_reachy.py

Step 3: Verify Same Subnet

Both devices should have IPs in the same range:

  • ✅ PC: 192.168.1.100, Reachy: 192.168.1.110 (same subnet)
  • ❌ PC: 192.168.1.100, Reachy: 192.168.0.110 (different!)

🔗 Connection Methods

Method A: Direct WiFi Hotspot (Initial Setup)

  1. Power on Reachy and wait 90 seconds
  2. Look for WiFi network: ReachyMini-XXXX
  3. Connect using password from robot's sticker
  4. Access: http://reachy-mini.local:8000/
  5. Or try: http://192.168.42.1:8000/

Method B: Home Network (Already Configured)

  1. Ensure both on EXACT same WiFi network
  2. Power on Reachy and wait 60 seconds
  3. Test: curl -X POST http://reachy-mini.local:8000/health-check
  4. If .local fails, use IP: http://192.168.1.110:8000/

🔬 Understanding mDNS (.local addresses)

What is mDNS?

mDNS (multicast DNS) allows devices to resolve hostnames ending in .localwithout a DNS server. It's how reachy-mini.local works.

⚠️ mDNS Limitations

  • Only works on same subnet (doesn't cross routers)
  • Blocked on many corporate networks
  • Requires Bonjour (Mac) or Avahi (Linux)
  • May not work with VPN active

If .local Doesn't Work

# Option 1: Use IP directly
curl -X POST http://192.168.1.110:8000/health-check

# Option 2: Add to hosts file
sudo echo "192.168.1.110 reachy-mini.local" >> /etc/hosts

# Option 3: Find IP via ARP
arp -a | grep b8:27:eb  # Raspberry Pi MAC prefix

⚠️ Common Network Pitfalls

IssueSymptomSolution
Different bands (2.4 vs 5GHz)Can't resolve .localConnect both to same band
Guest network isolationNo connection at allUse main network only
Mesh network roamingIntermittent connectionLock to same access point
Corporate networksmDNS blockedUse direct IP
VPN activeDifferent networkDisconnect VPN