Using Flashy With Bluetooth Module Causes Transfer Error

[elmfrain]

I've been trying circle for the past week and it works great!

So then I tried to enable the flashing functionality so I can more quickly upload my code the Raspberry Pi. I don't have a USB to Serial adapter, but I do have a HC-06 Bluetooth module. It basically does the same thing but wirelessly, and I made sure that the module is running at the 115200 baud rate. I can confirm that data is being transferred correctly.

So then I tried this:

• Added FLASHBAUD = 115200, USEFLASHY = 1, SERIALPORT = /dev/rfcomm0 to `Config.mk
• Did npm install for Flashy
• Did make all in /boot circle directory, giving me the firmware and the Kernel.img of the bootloader.
• Put files into SD card of Raspberry PI (Zero) and booted it up.

I think I setup the flashing functionality correctly.

However, when I do make flash on my project, I get this:

node  ../circle/tools/flashy/flashy.js \
        /dev/rfcomm0 \
        --flashBaud:115200 \
        --userBaud:115200 \
        --reboot: \
         \
        kernel.hex

Opening /dev/rfcomm0 at 115200...ok
Sending reset command...ok
Waiting for device...ok
Fast mode enabled
Sending............................ok
Finished in 0.1 seconds.
Sending go command...

An error occurred during the transfer: format
make: *** [../circle/Rules.mk:223: flash] Error 9

Yeah, so am I doing something wrong here, or is it a bug?

[rsta2]

Unfortunately the developer of Flashy is not available any more. Because it works all right with a normal USB-to-serial adapter here, I can only guess that this problem is caused by the specifics of your Bluetooth adapter (e.g. increased latency). Have you tried the default bootloader (without USEFLASHY = 1)?

[elmfrain]

Yeah, I tried using the python flasher (without USEFLASHY = 1), but for some reason, it doesn't work on my machine because I get this:

python3 ../circle/tools/flasher.py kernel.hex /dev/rfcomm0 115200
ERROR: Serial Port /dev/rfcomm0 busy or inexistent!

Nevertheless though, I just received a USB to Serial adapter today (an FTDI breakout board), and it finally works!

Sending reset command...ok
Waiting for device...ok
Fast mode enabled
Sending.......................ok
Finished in 39.2 seconds.
Sending go command...ok
Closing serial port...ok
Done!

So my guess is that you are right! The Bluetooth module has too much latency, and Flashy wasn't designed for that.

Although, it wouldn't be a bad idea for the Bluetooth module to work with Flashy. It allows for remote development, and it can be convenient. Maybe something to work on in the future!

[elmfrain]

Good News!

I've been tinkering with Flashy's code, and I've actually got the HC-06 Bluetooth to work! I don't know exactly how I got it to work, but I somewhat know. In simple terms, the flasher rams too much data at once which causes some data to get scrambled during transfer.

I'm planning to contribute my findings, but I want to iron out my research and code before I publicize it. I'd also want to know if it could work with the faster HC-05 Bluetooth module. The HC-05 has a max baud rate of 1382400, so this can be a great solution to wireless programming!

[rsta2]

Some time has passed now and I want to ask, if you have been successful with your research work about using Flashy with the HC-05 Bluetooth module? Is there something, you can contribute?

[elmfrain]

My apologies for the wait. Yes the HC-05 does work with Flashy flawlessly, however the HC-06 does need Flashy to work a little differently or else the data gets corrupted (perhaps it can't handle mass data). I'll publish my findings in a PR tomorrow from now.

[rsta2]

Solved in Circle 45.