xctu remote firmware over the air (OTA) update fails every time

When using the xctu tool for remote over-the-air firmware updates, it fails every time and then places the radio into recovery mode.

This is on a network of ~100 xbee nodes, most of which are routers.

Reading through the forum, it seems as if this is expected behavior for XCTU. Are there other options for updating firmware? Could a MCU (like the ATMEGA328) flash the xbee?

Which XBee product and firmware version are you trying to perform the OTA upgrade with?

Its an xbee pro s2b (XBP24BZ7UIT-004) with the most recent router firmware. I am trying to update it to the most recent end device firmware.

Yes , if you have sufficient room on your processor, you could perform the firmware upgrade following the steps outlined in the product manual and on Embers documentation.

I’ve read through the manual, and have a decent grasp on how I might accomplish this.

One sticking point for me is I would like to communicate with the xbee s2b’s bootloader at 57600 or slower. I would imagine that is possible by changing out the bootloader. I’ve been search for documentation regarding doing this, but I cannot seem to find any.

Can you point me in the right direction?

I would suggest looking at Embers documentation for that as Digi is using a modified Ember bootloader. Just understand that if you replace the bootloader, Digi will be unable to assist you.