FAQ
TL;DR: A TR6260’s full 1 MB backup flashes in ~2 – 3 minutes, and “TR6260 can now be flashed via UART with OBK” [Elektroda, p.kaczmarek2, post #21351236] Use UTP at 921 600 bps and ground GPIO14 to enter boot mode.
Why it matters: Local firmware liberates Tuya devices from cloud lock-in and enables Home-Assistant auto-discovery.
Quick Facts
• SoC: 32-bit 2.4 GHz Wi-Fi, 6 PWM, single ADC, 1 MB flash [Elektroda, p.kaczmarek2, post #21351236]
• Typical baud for flashing: 921 600 bps; fallback 115 200 bps [Elektroda, Guide, post #21351236]
• Backup size: exactly 1 048 576 bytes [Elektroda, Guide, post #21351236]
• Flash tool: UTP v1.3; esptool incompatible [Elektroda, Guide, post #21351236]
• Reported RSSI may drop ≈ 15 dB after OBK flash, no functional loss observed [Elektroda, morgan_flint, post #21421792]
Which TR6260 pins are essential for UART flashing?
Connect UART0_TXD (pad TXD) to USB-TTL RX, UART0_RXD (pad RXD) to USB-TTL TX, VCC to 3.3 V, GND to GND, and hold GPIO14/TOUT2 low during power-up to enter UART boot mode [Elektroda, morgan_flint, post #21405320]
How do I create a factory backup?
- Ground GPIO14.
- Power the module and open UTP.
- Read 0x000000–0x0FFFFF to a file; size must be 1 048 576 bytes.
A full dump avoids soft-brick risk [Elektroda, Guide, post #21351236]
Why does flashing sometimes fail at “RAM Download uboot file fail”?
Uploading a raw 1 MB image alone returns that error. Always prepend boot_nocrc.bin at address 0x0000, then the backup or OBK image [Elektroda, divadiow, post #21407688]
What files are needed for a clean OBK install?
• boot_nocrc.bin @ 0x0000
• TR6260_partition_at_diff_0x6000.bin @ 0x6000
• OpenTR6260_xxxx.bin @ 0x7000
File 4 is no longer required [Elektroda, p.kaczmarek2, post #21351236]
Which baud rate shows correct boot-loader text?
The loader prints legibly at 58 000 bps; 57 600 bps yields gibberish on some modules [Elektroda, morgan_flint, post #21405320]
Does the OBK build support sensors?
Yes. Drivers for DHT11, BME/BMP280, DS18B20 and SHT3X are compiled in; enable them with startDriver commands or template GUI [Elektroda, p.kaczmarek2, #21351236; divadiow, #21367101].
Is power-save active on TR6260 builds?
The SDK sets wifi_config.sta_ps_mode = 1 at compile time, so extra PowerSave commands are unnecessary [Elektroda, insmod, post #21426475]
Why is Wi-Fi RSSI weaker after reflashing?
OBK reports ~15 dB lower RSSI than stock, yet maintains stable links; metric is cosmetic, RF table in flash stays intact when boot_nocrc.bin is preserved [Elektroda, morgan_flint, post #21421792]
Can I restore stock firmware?
Yes. Flash boot_nocrc.bin @0x0000, then the saved 1 MB backup @0x0000 in UTP. Device reboots with Tuya cloud firmware [Elektroda, divadiow, post #21416923]
What edge cases should I test?
• Boot with both BT0 and BT1 grounded prints “unsupport boot mode” and halts [Elektroda, morgan_flint, post #21405320]
• Pins 16 and 17 lack GPIO mode; avoid mapping outputs there [Elektroda, insmod, post #21419965]
How do I enable Home-Assistant discovery?
After Wi-Fi setup, run:
- setChannelType 1 Relay
- startDriver Wemo
HA and Alexa detect the switch via SSDP in ~30 s [Elektroda, divadiow, post #21367101]
What if the device draws too much standby current?
Use PowerSave 1 on legacy BK chips; TR6260 already sleeps. Measure 45 mA active vs ≤8 mA idle on HLK-M20 board (typical lab reading) [Elektroda, Guide, post #21351236]
Do I need to split backups for partial restore?
Splitting isn’t required anymore; flashing the full image works when boot_nocrc.bin precedes it [Elektroda, divadiow, post #21407688]
Where can I get the SDK and datasheets?
Community mirrors host them at github.com/divadiow/TR6260 and NonPIayerCharacter/OpenTR6260 [Elektroda, insmod, post #21358543]
What is the cost of TR6260 development boards?
HLK-M20 modules sell for US $4–6, or US $8–12 with breakout PCB on AliExpress (April 2025 price sweep) [Elektroda, thread pricing, #21351236].
How long does a flash erase take?
Full-chip erase via UTP requires roughly 25 s at 921 600 bps before write starts [Elektroda, divadiow, post #21353666]
