#bluetooth · 8sync News

Quectel FCM365X dual-band WiFi 6, BLE 5.4, 802.15.4 IoT module features NXP RW612 MCU, optional PSRAM

Quectel has officially launched the FCM365X, a compact 25.5×18mm IoT module built on the NXP RW612 wireless MCU. It supports dual-band Wi-Fi 6, Bluetooth 5.4 LE, and 802.15.4 (Zigbee, Thread, Matter over Thread), with 8MB SPI flash and optional PSRAM — making it the only RW612-based module currently offering on-module PSRAM. The module exposes a wide range of interfaces (GPIO, UART, USB, I2C, I2S, ADC, LCD, PWM) via LCC+LGA packaging and operates from -40°C to +85°C. Development is SDK-based via QuecOpen; AT command firmware is not available. Two development boards are planned but details and pricing are not yet published.

A T9 Keyboard For Your Smartphone

A hardware enthusiast built a custom T9-style keypad using the physical keypad from a Nokia E52, mounted on a custom PCB with Alps SKRK tactile switches, an ESP32-C6 microcontroller, and Bluetooth connectivity. The device lets users type on modern smartphones using the classic multi-tap number key input method. A second revision improved the feel by switching to firmer 1.57 N actuation force switches.

Sleep Tracking, Bluetooth Signals, and EMF: What Every Wearable User Should Know

Sleep tracking wearables like the Oura Ring and Apple Watch use Bluetooth Low Energy (BLE), which transmits at 1–10 milliwatts — far below the power of a phone call and well within FCC and ICNIRP SAR safety limits. WHO-commissioned systematic reviews published in 2024–2025 found no causal link between RF-EMF exposure below safety thresholds and sleep disruption. A common mistake is citing ELF (50–60 Hz power line) melatonin studies to argue against 2.4 GHz Bluetooth devices — these are different parts of the spectrum with different biological interaction mechanisms. For those still concerned, enabling airplane or low-power mode at night reduces wireless transmissions while preserving most sensor-based tracking. The more significant risk from sleep trackers may actually be 'orthosomnia' — anxiety driven by obsessing over inaccurate sleep stage estimates that wearables infer from movement and heart rate rather than measure directly.