B4R Code Snippet [ESP32] .bin merging and flashing

It's all was for old B4R versions supporting only Arduino 1.x.

Merging 3 .bin files from B4R Object\bin folder into a single firmware file "merged-flash.bin":
Flashing "merged-flash.bin" file into the board via COM-port and esptool.exe:
esptool.py v4.5.1
Wrote 0x115300 bytes to file ..\Objects\bin\merged-flash.bin, ready to flash to offset 0x0
Completed. Exit code: 0

Forgotten to plug USB-cable from the board:
esptool.py v4.5.1
Found 0 serial ports
A fatal error occurred: Could not connect to an Espressif device on any of the 0 available serial ports.
Completed. Exit code: 2

Flashing: do not forget
  1. disconnect log of B4R from COM-port
  2. set the flash-mode by the board buttons (usually holding BOOT press and release EN and next release BOOT) of ESP32 module just after the IDE link clicked !
esptool.py v4.5.1
Found 1 serial ports
Serial port COM6
Chip is ESP32-D0WDQ6 (revision v1.0)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 08:3a:f2:a7:8e:ac
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Configuring flash size...
Flash will be erased from 0x00000000 to 0x00115fff...
Compressed 1135360 bytes to 691197...
Writing at 0x00000000... (2 %)
Writing at 0x0001293e... (4 %)
Writing at 0x0001d2a0... (6 %)
Writing at 0x00028e11... (9 %)
Writing at 0x0003753f... (11 %)
Writing at 0x0003cbef... (13 %)
Writing at 0x00042574... (16 %)
Writing at 0x00047b99... (18 %)
Writing at 0x0004d0ea... (20 %)
Writing at 0x00052591... (23 %)
Writing at 0x00057e00... (25 %)
Writing at 0x0005d29c... (27 %)
Writing at 0x000624f0... (30 %)
Writing at 0x00068905... (32 %)
Writing at 0x0006e1b6... (34 %)
Writing at 0x00073eb4... (37 %)
Writing at 0x00079697... (39 %)
Writing at 0x0007f399... (41 %)
Writing at 0x00085000... (44 %)
Writing at 0x0008a7c0... (46 %)
Writing at 0x0008fee3... (48 %)
Writing at 0x00095475... (51 %)
Writing at 0x0009ab7f... (53 %)
Writing at 0x000a089b... (55 %)
Writing at 0x000a6422... (58 %)
Writing at 0x000ad188... (60 %)
Writing at 0x000b3064... (62 %)
Writing at 0x000b8970... (65 %)
Writing at 0x000be494... (67 %)
Writing at 0x000c3928... (69 %)
Writing at 0x000c9190... (72 %)
Writing at 0x000cee30... (74 %)
Writing at 0x000d4bd8... (76 %)
Writing at 0x000daf88... (79 %)
Writing at 0x000e0b32... (81 %)
Writing at 0x000e6490... (83 %)
Writing at 0x000ebe54... (86 %)
Writing at 0x000f2744... (88 %)
Writing at 0x000fb045... (90 %)
Writing at 0x00102f8b... (93 %)
Writing at 0x001091f5... (95 %)
Writing at 0x0010e69e... (97 %)
Writing at 0x00114150... (100 %)
Wrote 1135360 bytes (691197 compressed) at 0x00000000 in 10.5 seconds (effective 863.3 kbit/s)...
Hash of data verified.
Hard resetting via RTS pin...
Completed. Exit code: 0

Commands for B4R IDE:
'Ctrl + click to merge binaries into merged-flash.bin: ide://run?file=%USERPROFILE%\AppData\Local\Arduino15\packages\esp32\tools\esptool_py\4.5.1\esptool.exe&args=--chip&args=ESP32&args=merge_bin&args=-o&args=..\Objects\bin\merged-flash.bin&args=--flash_mode&args=dio&args=--flash_size&args=4MB&args=0x1000&args=..\Objects\bin\src.ino.bootloader.bin&args=0x8000&args=..\Objects\bin\src.ino.partitions.bin&args=0x10000&args=..\Objects\bin\src.ino.bin
'Ctrl + click to flash into ESP32 board: ide://run?file=%USERPROFILE%\AppData\Local\Arduino15\packages\esp32\tools\esptool_py\4.5.1\esptool.exe&args=--chip&args=ESP32&args=--baud&args=921600&args=write_flash&args=0x0&args=..\Objects\bin\merged-flash.bin
where "%USERPROFILE%....." is your path to "esptool.exe" installed in Arduino IDE v.1.x.

These 2 links are useful for re-flashing the board if the B4R sketch was already compiled.
Last edited:

Hamied Abou Hulaikah

Well-Known Member
Licensed User
Longtime User
You mentioned one benefit of this is remote update, How can you update/replace app bin remotely inside IC?


Licensed User
Longtime User


Licensed User
Longtime User
Addition for Arduino 2.x - copying all the generated files during compilation into B4R Objects\bin folder:

Command for B4R IDE v.4.0+:

'Ctrl + click to copy FW file of Arduino 2.x: ide://run?file=%WINDIR%\System32\Robocopy.exe&args=%USERPROFILE%\AppData\Local\Temp\arduino\sketches\613611983B1DC48F5240C428509155C2&args=..\Objects\bin&FilesSync=True

, where "613611983B1DC48F5240C428509155C2" is the unique subfolder created by Arduino 2.x automatically for your sketch.
This folder can be found in the B4R log after compilation is complete.

Merging ESP32 partitions after Arduino 2.x:
'Ctrl + click to merge binaries into merged-flash.bin: ide://run?file=%USERPROFILE%\AppData\Local\Arduino15\packages\esp32\tools\esptool_py\4.5.1\esptool.exe&args=--chip&args=ESP32&args=merge_bin&args=-o&args=..\Objects\bin\merged-flash.bin&args=--flash_mode&args=dio&args=--flash_size&args=4MB&args=0x1000&args=%USERPROFILE%\AppData\Local\Temp\arduino\sketches\5F246370AC91E228B24A8A187BD6F440\src.ino.bootloader.bin&args=0x8000&args=%USERPROFILE%\AppData\Local\Temp\arduino\sketches\5F246370AC91E228B24A8A187BD6F440\src.ino.partitions.bin&args=0x10000&args=%USERPROFILE%\AppData\Local\Temp\arduino\sketches\5F246370AC91E228B24A8A187BD6F440\src.ino.bin
Last edited: