Using Adafruit Feather or ItsyBitsy

I am building a relay device that needs to collect data via a serial port. I also need to use Outboard Firmware Update because I want to add features. The Swan board looks good because it has multiple serial ports. I am also trying to squeeze it all in a small enclosure using a Notecarrier B. I am very familiar with Adafruit Feather and other boards, and have numerous Feather and ItsyBitsy boards lying around.

It seems that I can’t use outboard firmware update and communicate with the Notecard via serial, and that I have to use I²C. I’m not sure that is correct.

Would it be possible/practical to use a Feather M0, communicating with the Notecard via I²C, and have Outboard Firmware Update available?

Thanks in advance,

Rob

Hi Rob!

If you are keen on using Outboard Firmware Update, then I think the Swan is the board you want.

I checked out the Adafruit Feather M0, and it appears to have a Atmel ATSAMD21. Unfortunately, that chipset is not supported by Outboard Firmware Update. Outboard Firmware Update predominately works with any ESP32 and STM32 chips with the boot pin exposed. The Swan is based on the STM32L4R5 and is therefore compatible.

It seems that I can’t use outboard firmware update and communicate with the Notecard via serial, and that I have to use I²C. I’m not sure that is correct.

Outboard Firmware Update works as an “In-system programmer” similar to an STLINK, JLink or ESP-Prog. It will physically manipulate the strapping pins and can rewrite the entire flash (if necessary).

EDIT: You are correct. Outboard Firmware Update will use the AUX TX/RX on the Notecard to rewrite the firmware via the UART (TX/RX) on the Swan.

You may communicate with the Notecard via I²C or Serial, based on your needs. That decision has no effect on your ability to use Outboard Firmware Update.

Hopefully this helps you get moving in the right direction.

Cheers,
Zak

1 Like

Hi Zak,

Thank you very much.

Is the I²C likely to be faster then the serial? I am finding working at 9600 baud a bit limiting.

Regards,

Rob

Hey Rob,

No, unfortunately I²C is quite a bit slower than UART.

If you are discussing the speed in the context of Outboard Firmware Update, then the good news is that it bypasses both I²C and UART altogether and is generally a quick operation.

Sincerely,
Zak