Flashing OpenBeken/OBK firmware to ESP8266/ESP8285 devices

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#61 21703172 28 Sep 2025 17:00

max4elektroda max4elektroda

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Post #61
21703172 28 Sep 2025 17:00

@Tilator do you know incidentally how multiple sensors on one device are handled? So we can follow this for the other driver, too?
If not, I can try to check the code ...

Added after 16 [minutes]:

No need to check - found it:

https://tasmota.github.io/docs/DS18x20/#multiple-sensors

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{"Time":"2021-01-02T09:09:44","DS18B20-1":{"Id":"00000566CC39","Temperature":13.3},"DS18B20-2":{"Id":"0000059352D4","Temperature":1.2},"DS18B20-3":{"Id":"000005937C90","Temperature":22.5},"TempUnit":"C"}

Sadly it doesn't use the human readable name but the ID...

Added after 2 [hours] 12 [minutes]:

Opened PR#1811 for the multiple DS1820 sensors.
There is one "plain" Tasmota version, adding "-<id>" to the sensor and an Id to identify the sensor (middle 48 bits from ROM address in reverse order).

Included is a (commented out) version which additionally adds a "Name": field in JSON:

(both images are with "wrong" index number, which is now corrected - Tasmota will start index with "-1" not with "-0")
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Topic summary

The discussion centers on flashing a 2MB OpenBeken/OBK firmware onto a 4MB ESP8266 board. Initial boot logs confirm successful recognition of the 4MB flash size with a detailed partition table including OTA data, WiFi NVS, two OTA app partitions, and an LFS partition. Users report smooth flashing and stable WiFi connectivity without resets after manual reboot. GPIO2 functionality is confirmed. Subsequent updates include added PWM and UART support, with UART implemented via a task-based polling method to avoid crashes seen with interrupt-driven approaches. PWM operates inverted but functional, with PWM_n also working as expected. OTA updates remain non-functional despite passing image checks. Adjustments to QuickTick timer handling and stack size were necessary to prevent crashes. Disabling PWM on GPIO0 resolved bootloop issues. Overall, the firmware demonstrates improved hardware compatibility and peripheral support on the 4MB ESP8266 platform.
Summary generated by the language model.

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Flashing OpenBeken/OBK firmware to ESP8266/ESP8285 devices

FAQ

TL;DR: You can safely flash the “2 MB” OpenBeken ESP-IDF image onto 4 MB or 8 MB ESP8266 boards—just keep the matching partition table; after PR #1707, OTA now works again on all sizes, handling images up to ~1 MB [Elektroda, insmod, post #21596825]

Quick Facts


• Supported flash sizes: 1 MB / 2 MB / 4 MB / 8 MB (common ESP8266 limits) [Elektroda, divadiow, #21595385; #21596199]
• Max OTA image size in ESP8266-RTOS SDK: 1 048 576 bytes (1 MB) [Espressif OTA Guide]
• Default OBK partition map (2-4 MB): 2× 0xE0000 OTA slots + 0x30000 LFS + NVS [Elektroda, boot log, #21595385]
• Fix that restored OTA on ≥4 MB boards: commit 2025-07-03, “partition layout corrected” [Elektroda, insmod, post #21596825]
• PWM console spam removed by updating duty only on change (25 ms loop disabled) [Elektroda, p.kaczmarek2, post #21596997]

Which ESP8266 flash sizes does the new OpenBeken build recognise?

Bootloader reports and works with 1 MB, 2 MB, 4 MB and 8 MB SPI flash chips [Elektroda, divadiow, #21595385; #21596199].

Can I flash the 2 MB image on a 4 MB or 8 MB module?

Yes. The image occupies the first 1 MB OTA slot; the extra space is unused unless you adjust the partition CSV before build [Elektroda, insmod, post #21596138]

What partition layout should I use?

Keep two 0xE0000 OTA slots starting at 0x10000 and 0xF0000, plus NVS and optional LFS. Use the provided partitions-2mb.csv for 2-4 MB, or enlarge offsets for 8 MB [Elektroda, insmod, post #21596825]

Why did OTA fail earlier and how was it fixed?

Older images wrote the second OTA slot outside valid flash range on bigger chips, triggering Exception 28. The July-03 patch realigned offsets and OTA now reboots cleanly [Elektroda, divadiow, #21596199; insmod, #21596825].

Does OTA work from Tasmota?

Not directly. Tasmota uses the NON-OS SDK, while OpenBeken uses ESP8266-RTOS SDK; cross-OTA requires a custom RTOS-format binary and a special stub per Espressif’s migration guide [Elektroda, insmod, post #21597062]

What is the maximum firmware size I can upload?

With the default map each OTA slot is 0xE0000 (917 504 bytes); ESP8266-RTOS SDK further limits proven images to 1 MB [Espressif OTA Guide].

How can I use the spare space on an 8 MB board?

Re-generate the partition CSV to give LFS several megabytes (e.g., 6 MB) for web assets or logs; firmware size stays the same [Elektroda, p.kaczmarek2, post #21597058]

Is gzip compression for WebApp files possible?

Yes. Serve pre-compressed .gz files and add the header Content-Encoding: gzip; LFS can first look for name.ext.gz before name.ext [Elektroda, insmod, #21597649; p.kaczmarek2, #21597813].

Why did PWM spam the console every 25 ms?

Old driver updated duty unconditionally; the fix triggers an update only on value change, removing the flood [Elektroda, insmod, #21596825; p.kaczmarek2, #21596997].

How is UART RX implemented in the RTOS build?

A simple task polls uart_read_bytes() and feeds a ring buffer; an interrupt version crashes on large bursts [Elektroda, insmod, post #21596138]

Does deep-sleep work?

Timer deep-sleep enters low-power mode but fails to wake on test boards; GPIO wake is not yet implemented in the SDK port [Elektroda, insmod, post #21597042]

Has Wi-Fi stability improved?

Yes. First-connect and reconnect bugs were cleared; modules stay online without resets for hours [Elektroda, insmod, #21596138; DeDaMrAz, #21596140].

Are there plans for UI or WebApp changes?

Developers discuss cleaning legacy fields, adding gzip uploads, and enlarging on-device WebApp for 8 MB modules [Elektroda, DeDaMrAz, #21597496; p.kaczmarek2, #21597272].