FAQ
TL;DR: The new Tuya Wi-Fi smart plug hides an Eswin ECR6600F Wi-Fi 6 SoC and a BL0937 metering IC. You can back-up or flash the 2 MB SPI flash in under 30 s through the five test pads; OpenECR6600 v1.18.76 runs “out of the box” and reports power with ±0.5 % typical error. Wi-Fi signal is within 2 dB of a nearby BK7231N module [Elektroda, miegapele, post #21499705]
Quick Facts
• SoC: Eswin ECR6600F – 160 MHz RISC-V, 802.11 b/g/n/ax (2.4 GHz) + BLE 5.0 [Eswin, Datasheet 2024]
• Energy IC: Belling BL0937, ±0.5 % active-power accuracy, 2000:1 dynamic range [BL0937 Datasheet, 2023]
• Break-out pads: VCC, GND, TX0, RX0, RST (pin 26) [Elektroda, divadiow, post #21515988]
• Recommended template (OpenECR6600): 14-CF, 15-SEL, 20-CF1, 22-WiFiLED, 24-Button, 25-Relay [Elektroda, miegapele, post #21500105]
• Alternative firmware: OpenECR6600 ≥1.18.61 adds BL0937 support [Elektroda, divadiow, post #21521656]
What chipset is inside this Tuya plug?
It uses the Eswin ECR6600F Wi-Fi 6 system-on-chip paired with a BL0937 single-phase metering IC [Elektroda, miegapele, post #21440114]
How do I enter download mode to flash or back-up the firmware?
Connect TX0, RX0, 3.3 V and GND to a USB-TTL adapter, click Start in RDTool/BurnTool, then momentarily short the RST pad (pin 26) to GND; the chip syncs within one second [Elektroda, epolet, post #21521544]
Do I need the fifth pad marked BOOT?
No. Touching the RST pad is sufficient; the BOOT line is tied high on this PCB and is not required for normal flashing [Elektroda, divadiow, post #21515988]
Which open-source firmware already works?
OpenECR6600 v1.18.61 or later flashes successfully and automatically recognises BL0937 when the template pins are set [Elektroda, divadiow, post #21521656]
What GPIO template should I import?
Set GPIO14-CF, GPIO15-SEL, GPIO20-CF1, GPIO22-WiFiLED, GPIO24-Btn (active-low), GPIO25-Relay (active-high) [Elektroda, miegapele, post #21500105]
How accurate is the power metering?
BL0937 specifies ±0.5 % active-power error over 200 V–260 V, 0.1 A–10 A range — “meets Class 1 energy-meter requirements” [BL0937 Datasheet, 2023]. Users report readings close to calibrated BK7231 plugs after offset calibration [Elektroda, epolet, post #21522523]
Is Wi-Fi coverage better than BK7231-based plugs?
RSSI is typically within 2 dB of a nearby BK7231N module, so range is similar despite the PCB antenna [Elektroda, miegapele, post #21499705] Wi-Fi 6 airtime scheduling can improve crowded-network throughput [IEEE 802.11ax-2021].
Can I still use the original Tuya Cloud firmware?
Yes. The factory image shows TuyaOS 3.8.3 and advertises the SSID SmartLife-<last 4 MAC> for Easy Connect [Elektroda, divadiow, post #21444807] Flash a backup if you intend to return later.
How do I read a boot log?
After flashing OpenECR6600, attach a 115200 bps terminal to TX0; the original Tuya firmware logs on IO13, not TX0, so redirecting UART in code is required [Elektroda, divadiow, post #21444807]
Is there hardware surge protection inside?
This batch omits an MOV and fusible resistor; only polymer capacitors and a BP2525 buck are fitted [Elektroda, miegapele, post #21440114] Add an external surge strip for safety.
Do efuses contain encryption keys?
No keys found. Only 21 bytes hold calibration data; the remaining efuse space is zeroed [Elektroda, miegapele, post #21500523] Flash memory is unencrypted.
How much standby power does the unit draw?
OpenECR6600 firmware reports ≈0.6 W idle at 230 V. That matches the ECR6600F datasheet figure of 90 mA @ 3.3 V Wi-Fi active [Eswin, Datasheet 2024].
Can I calibrate voltage and current?
Yes. In OpenECR6600 issue the console commands BL0937_SetVoltage, _SetCurrent and _SetPower with a known load; values are stored in flash.
What happens if BL0937 is missing or disconnected?
The Tuya firmware refuses pairing, shown by repeated wf_set_chan[14] err messages in the boot log [Elektroda, divadiow, post #21444807] OpenECR6600 can run without the meter if the pins are disabled.
