FAQ
TL;DR: Measured −79 dBm at the Sonoff Mini R2 [Elektroda, pioooo9999, post #21326091] “−80 dB is the limit for internet devices” [Elektroda, Erbit, post #21326136] Your 2.4 GHz channel is crowded; change the Huawei router’s channel and use 20 MHz width [MetaGeek, 2024].
Why it matters: This FAQ helps Sonoff/eWeLink users fix disappearing devices by improving 2.4 GHz coverage and reducing channel interference.
Quick Facts
- Sonoff Mini R2 uses 2.4 GHz 802.11 b/g/n only; works with eWeLink [ITEAD, 2024]. Schedules execute locally on the device (offline capable) [eWeLink, 2023].
- Target Wi‑Fi strength: ≥ −67 dBm is strong; −70 to −80 dBm is borderline for reliability [MetaGeek, 2024].
- Use non‑overlapping 2.4 GHz channels 1, 6, or 11; set channel width to 20 MHz [MetaGeek, 2024].
- Typical interior wall attenuation: ~3–6 dB; metal enclosures can add 20–50 dB loss [Ekahau, 2020].
- If coverage is weak, a basic 2.4 GHz extender/mesh node costs approx. $40–$120 [Wirecutter, 2024].
Is my Sonoff Mini R2 disappearing from eWeLink because of Wi‑Fi coverage?
Very likely. You measured −79 dBm near the device, which is borderline. IoT can work there, but reliability drops and discovery/control often fail [Elektroda, pioooo9999, #21326091; MetaGeek, 2024]. Your scan also showed many networks on the same channel, increasing interference [Elektroda, Erbit, post #21327758]
Why does scheduling still work even when the device is offline in the app?
Schedules are stored and executed locally on Sonoff devices. So timed actions can work while cloud/app control is unavailable, as long as power remains [eWeLink, 2023]. “Offline schedule execution is by design for reliability” [eWeLink, 2023].
How do I check if channel congestion is my problem?
Do a quick site survey near the Mini R2 with WifiMonitor/WiFi Analyzer. 1) Stand next to the switchboard. 2) Note RSSI and list of 2.4 GHz channels in use. 3) Capture a screenshot [Elektroda, Erbit, post #21325874] Many SSIDs on your channel indicate co/adjacent‑channel interference [MetaGeek, 2024].
How do I change the 2.4 GHz channel on a Huawei router?
1) Log in to the router admin page, open WLAN/Wi‑Fi settings. 2) Select 2.4 GHz, disable Auto channel, set channel to 1, 6, or 11 (start with the least congested). 3) Set channel width to 20 MHz, save, and reboot if prompted [Huawei Support, 2024; MetaGeek, 2024].
Which channel should I pick: 1/6/11 or 9 (as suggested in the thread)?
Standards guidance is 1, 6, or 11 to avoid overlap [MetaGeek, 2024]. The thread advice to try 9 can work as a temporary dodge if 1/6/11 are packed, but it overlaps neighbors and may regress later [Elektroda, Erbit, #21328223; MetaGeek, 2024].
What RSSI should I aim for at the Sonoff Mini R2?
Aim for at least −67 dBm for stable control. −70 to −80 dBm often connects but can drop, especially with interference [MetaGeek, 2024]. A 3 dB loss halves signal power, so small changes in placement matter [MetaGeek, 2024].
Does a plastic switchboard attenuate Wi‑Fi, and what if it’s metal?
Thin plastic adds little attenuation. Metal enclosures can block 20–50 dB, which is severe [Ekahau, 2020]. If the board is metal, route the device outside or use an external antenna model/AP closer to it [Ekahau, 2020].
Can the nearby solar inverter Wi‑Fi interfere?
Yes, if it broadcasts on the same/overlapping 2.4 GHz channel, it adds contention. Your scan showed many networks, including the inverter SSID [Elektroda, Erbit, #21327782; Elektroda, pioooo9999, #21328134]. Move your router to a cleaner channel [MetaGeek, 2024].
My Mini R2 is 15 m from the router. Is that too far for 2.4 GHz?
Distance is fine for 2.4 GHz in open space, but walls and interference dominate. At −79 dBm you’re at the edge; improve channel selection or move/raise the AP slightly to gain a few dB [Elektroda, pioooo9999, #21326091; MetaGeek, 2024].
Router settings to stabilize Sonoff/eWeLink?
- Lock 2.4 GHz to 20 MHz width. - Pick 1/6/11 with least congestion. - Disable band steering/“Smart Connect” for the IoT SSID. - Keep WPA2/WPA3‑SAE Mixed off for legacy IoT; use WPA2‑PSK/AES [MetaGeek, 2024; ITEAD, 2024].
Should I create a separate 2.4 GHz SSID for IoT devices?
Yes. A dedicated IoT SSID at 2.4 GHz avoids band steering and lets you set conservative channels and widths. It reduces contention with 5 GHz clients and simplifies troubleshooting [MetaGeek, 2024].
Will a repeater or mesh node help in this case?
If channel tuning isn’t enough, add a nearby 2.4 GHz AP/mesh node to lift RSSI above −67 dBm. Use wired backhaul if possible to avoid extra airtime consumption on 2.4 GHz [Wirecutter, 2024; MetaGeek, 2024].
Why might the issue return after I change channels?
Neighbors on Auto can migrate onto your channel later. The thread notes it may break again “until someone comes up with the same idea” [Elektroda, Erbit, post #21327758] Re‑survey monthly and adjust if needed [MetaGeek, 2024].
