Week 11 — Networking and communications

This week’s topic: Networking and communications.

Group assignment

In Shenzhen Chaihuo, we documented a two-node communication workflow that combines wireless BLE interaction and wired signal verification. The goal was to prove not only connection success, but also reconnect logic and bus-level evidence.

Work objective

• Demonstrate direct communication between two embedded nodes.
• Show state transitions (scan, connect, disconnect, reconnect) in real time.
• Capture communication signals to support software behavior with hardware evidence.

1) Test setup and hardware

• XIAO ESP32-C3 x 2 (server/client roles)
• OLED displays over I2C (address 0x3C)
• Breadboard, jumpers, optional antenna comparison
• Logic analyzer for I2C decoding and signal review

2) BLE communication validation

The server node advertised a fixed service while the client scanned for target device name and connected on discovery. After disconnect events, reconnect attempts were verified to confirm realistic behavior in unstable conditions.

3) Logic-analyzer observation of display bus

While BLE state updates were shown on OLED, I2C traffic was captured to confirm that display updates corresponded to real bus transactions.

4) Packet interpretation notes

Packet	Observed bytes	Interpretation
Packet 1	0x3C WR, 0x40, ...	Expected OLED write transaction with valid data flow.
Packet 2	0x23 WR, ...	Likely noise or decode artifact; secondary to expected target address traffic.

5) Topology concept references

Result summary

• Two-node BLE communication was successfully demonstrated.
• OLED state feedback helped debug connection lifecycle clearly.
• I2C capture confirmed display communication at signal level.
• The workflow is usable as a foundation for later multi-device integration.