ble-connectivity

name	ble-connectivity
description	Implement BLE connectivity — GATT services, pairing, advertising, and BLE Mesh networking
allowed-tools	["Read","Write","Grep"]
effort	medium

When to activate

• Implementing BLE GATT services and characteristics
• Designing BLE advertising and scanning strategies
• Implementing BLE pairing and bonding
• Building BLE Mesh networks for IoT
• Debugging BLE connection issues and throughput

When NOT to use

• For WiFi-only IoT devices
• For classical Bluetooth audio (A2DP)
• For NFC or RFID systems

Instructions

1. Define GATT profile. Services (group related data), Characteristics (individual values), Descriptors (metadata). Use standard SIG profiles where possible.
2. Advertising. Include service UUIDs. Use scan response for extra data. Interval trade-off: fast = discoverable, slow = power efficient.
3. Connection parameters. Interval (7.5ms-4s), latency (skip intervals), timeout. Negotiate for use case: low latency vs power.
4. Pairing. Just Works (no MITM protection), Passkey (MITM protection), OOB (out-of-band key). Choose based on security needs.
5. Throughput. DLE (Data Length Extension) for larger packets. MTU negotiation. Notifications > Indications (no ack needed).
6. BLE Mesh. Provisioning, relay nodes, publish/subscribe model. For many-to-many communication (lighting, sensors).
7. Debugging. BLE sniffer (nRF Sniffer). Connection event logging. RSSI monitoring for range issues.

Example

BLE GATT Profile: Environmental Sensor

Service: Environmental Sensing (0x181A)
  Characteristic: Temperature (0x2A6E) — sint16, 0.01°C resolution, notify
  Characteristic: Humidity (0x2A6F) — uint16, 0.01% resolution, notify
  Characteristic: Pressure (0x2A6D) — uint32, 0.1 Pa resolution, read

Service: Device Information (0x180A)
  Characteristic: Manufacturer (0x2A29) — string, read
  Characteristic: Firmware Rev (0x2A26) — string, read

Advertising: 100ms interval, include Environmental Sensing UUID
Connection: 30ms interval, 0 latency, 4s timeout