Document ESP32 hardware bring-up results

docs/hardware-status.md

@@ -278,3 +278,130 @@ Current Logging Plan:
 
 - No persistent logging planned
 - Focus on live monitoring and alarms
+
+## ESP32 Cargo Controller Bring-Up Results
+
+### Date
+
+2026-06-04
+
+### Hardware
+
+- ESP32 2-channel relay board
+- ESP32-WROOM-32
+- Integrated dual relay module
+
+### Firmware Status
+
+- Firmware compiles successfully
+- Firmware uploads successfully
+- Board boots reliably
+- No watchdog resets observed
+
+### WiFi Access Point
+
+Status: PASS
+
+Verified:
+
+- AP starts correctly
+- SSID visible
+- Client devices can connect
+- HTTP API accessible
+
+### Status Endpoint
+
+Status: PASS
+
+Endpoint:
+
+    /status
+
+Issue Found:
+
+- Original streaming JSON implementation produced malformed responses
+- Browser reported "cannot parse response"
+
+Resolution:
+
+- Replaced streamed response with serialized JSON string response
+
+Result:
+
+- Valid JSON returned successfully
+
+### Relay Control
+
+Status: PASS
+
+Verified:
+
+    /relay/starlink/on
+    /relay/starlink/off
+    /relay/fridge/on
+    /relay/fridge/off
+
+Results:
+
+- Relay 1 responds correctly
+- Relay 2 responds correctly
+- Relay state updates correctly
+- Relay state reflected correctly in status API
+
+### Relay Default State
+
+Issue Found:
+
+- Fridge relay defaulted to ON
+
+Root Cause:
+
+    bool fridge = true;
+
+Resolution:
+
+    bool fridge = false;
+
+Result:
+
+- Both relays now default OFF at boot
+
+### DS18B20 Testing
+
+Status: BLOCKED
+
+Hardware:
+
+- Waterproof DS18B20 sensors
+- 5 meter leads
+
+Current Result:
+
+- Sensors not detected
+
+Likely Cause:
+
+- Missing 4.7kΩ pull-up resistor on 1-Wire bus
+
+Planned Fix:
+
+- Install 4.7kΩ resistor between GPIO4 and 3.3V
+- Retest sensor detection
+
+### Overall Milestone Status
+
+ESP32 Hardware Bring-Up
+
+Status: COMPLETE
+
+Completed:
+
+- Boot validation
+- WiFi validation
+- HTTP API validation
+- Relay validation
+
+Remaining:
+
+- DS18B20 validation after resistor installation
+