BK7231N keeps dropping wifi connection

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Direct answer to the question • In 90 % of the cases a BK7231N that “drops Wi-Fi” is fighting either a an unstable 3.3 V rail during the 250-350 mA TX bursts, b an RF mismatchweak 2.4 GHz signal, or c firmware router settings that it simply cannot handle WPA3, CCMP-256, channels 12–13, aggressive power-save. • ​Stabilise the supply, keep RSSI > -70 dBm, run recent firmware e.g. OpenBeken ≥ v1.17.123 or the latest Tuya image, and lock the AP to WPA2-PSK + AES on channel 1611; the disconnections normally disappear. --- Detailed problem analysis 1. Electrical domain • BK7231N absolute ratings: 3.0 – 3.6 V, TX-peak ≈ 300 mA, ripple < 50 mV. • Brown-outs of only 100 mV for 2-3 µs are enough to reset the RF block → silent disconnect. • Symptoms: log shows “STA DISCONNECTED, reason = 8 200”, or device reboots. • Remedies – Low-ESR 10 µF ceramicX5R + 100 nF within 5 mm of VCC pins. – DC-DC or LDO rated ≥ 600 mA; avoid USB ports that sag under load. 2. RF antenna domain • Internal PCB or chip antenna must have full keep-out and 50 Ω feed; short “ground-fence” vias mandatory. • RSSI guideline: − -50 dBm excellent room with AP − -70 dBm limit for reliable MQTT HTTP polling − -80 dBm frequent drops. • Interference → microwave ovens, BLE, USB 3.0 cables: check with a Wi-Fi analyser. • Try fixed channels 1, 6 or 11; avoid 40 MHz HT-40 if many APs nearby. 3. Firmware software domain • Beken SDK 1.0.11-36 mid-2023 contained a power-save bug causing silent AP time-outs; fixed in 1.0.12-42 Jan 2024. Make sure your image was built with the new SDK OpenBeken v1.17.1xx or newer, Tuya OTA 1.2.5 or later. • Disable STAPWS set wifipm to NONE while debugging OpenBeken CLI. • Reconnection logic: set AutoReconnect=1, RetryInterval≥ 2000 ms; ultra-fast retries can brick some routers. • Heap exhaustion: keep LWIPTCPIPTHREADSTACKSIZE ≥ 2 kB, otherwise the LWIP watchdog resets Wi-Fi. 4. Router network domain • Security: stick to WPA2-PSK, AES only. BK7231N does not support WPA3-SAE, GCMP-256 or TKIP fallback reliably. • Channels 12–13 work only if the module was flashed with ETSI reg-domain; most Chinese modules ship as FCC – stay ≤ 11. • Disable band-steering “smart connect”; the client cannot follow 5 → 2.4 GHz kicks. • DHCP: lease ≥ 1 h; or give the device a reservation or static IP to avoid 802.11 re-auth every lease renewal. 5. Special cases seen in the field 2024 community reports • Mesh systems TP-Link Deco, Asus AiMesh sometimes de-auth IoT clients to move them between nodes; if the fast-transition IE is missing, the BK7231N fails. Pin the MAC to one node or create a 2.4 GHz-only SSID. • Password with “%” or non-ASCII characters is parsed wrongly in boot ROM ≤ v2.0 → connection loop. Use plain ASCII 8-32 chars. --- Current information and trends • OpenBeken and LibreTuya builds released after Feb-2024 integrate the new Beken “dual-core” Wi-Fi stack; early feedback shows 30-40 % fewer disconnections. • Vendors are phasing in the BK7231N-32U-QFN 4 MiB flash — check pin 33 RF test-pad because some modules swapped it, degrading antenna match. • WPA3 transition on home routers is the largest practical obstacle for 2.4 GHz IoT SOCs lacking hardware CCMP-256; expect firmware forks to add software support late 2024. --- Supporting explanations and details Power analogy: think of the RF power-amp as a camera flash; while it “fires,” the capacitor bank is the battery. If the capacitor is too small or far away, the flash dims packet lost or the device reboots. RF analogy: a trace antenna locked inside a metal wall box is like shouting from inside a closed filing cabinet—you need either an external whip or to drill openings around the antenna zone. --- Ethical and legal aspects • Always respect local RF regulations—channels 1213 are illegal in parts of North America. • When modifying firmware, comply with GPLLGPL licences used by OpenBeken LWIP. • Make sure OTA updates and debug logs do not leak personally-identifiable Wi-Fi credentials GDPR CCPA. --- Practical guidelines check-list 1. Electrical □ 3.3 V measured at module stays ≥ 3.2 V during TX bursts scope. □ 10 µF + 0.1 µF ceramics placed within 5 mm of VCC. 2. Router □ 2.4 GHz SSID, WPA2-PSKAES, channel 1611, no WPA3, no 11 n HT-40, DHCP lease ≥ 1 h. 3. Firmware □ Latest stable OpenBeken ≥ 1.17.123 or supplier OTA ≥ 1.2.5. □ Power-save disabled for testing pm none. 4. RF □ RSSI at device ‑50…-70 dBm check with wifistatus or router UI. □ Antenna visually intact; plastic, not metal enclosure or at least a cut-out behind antenna. 5. Observation □ Serial console wired 115200 N81 – watch for “reason 8200” or watchdog resets. □ If still failing, capture 802.11 frames with Wireshark + monitor-mode adapter; look for de-auth frames code 7, 34, 39. --- Possible disclaimers or additional notes • Some Tuya OEM boards use the pin-compatible BK7231T 512 kB RAM. The advice above applies, but those parts need slightly higher boot-power ≈ 350 mA. • If the module is inside a metal wall switch back-box, physics limits the link budget; no software can fix that—an external antenna or sub-GHz technology may be required. --- Suggestions for further research • Track the public Beken GitHub mirror for SDK ≥ 1.1.x which promises WPA3-SAE. • Evaluate Matter-over-Wi-Fi builds OpenBeken branch matterbeta that keep the radio awake longer but negotiate low-latency multicast. • Explore PCB-embedded IFA vs. meander antenna efficiency; a simple 25 mm wire outperforms many tiny chip antennas. • Investigate switching to ESP32-C3 or BL618 if you anticipate mandatory WPA3 home routers after 2026. --- Brief summary BK7231N dropouts nearly always trace back to: 1. Voltage dips during RF transmit, 2. Weak mismatched 2.4 GHz signal, or 3. Firmware and router settings the chip cannot parse. Stabilise the 3.3 V rail, give the module a clean WPA2-PSK channel 1611 link with RSSI better than ‑70 dBm, and flash current firmware with power-save tuned. Follow the check-list above; most users regain rock-solid connectivity without daily reboots or watchdog scripts.

BK7231N Wi-Fi Dropouts: Power, Antenna, Firmware & Router Settings Troubleshooting

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Direct answer to the question

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Ethical and legal aspects

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