How to use a Raspberry Pi to flash new firmware onto the Coral Dev Board
If you’ve managed to get hands on with one of Google’s new Coral Dev Boards you might be a little surprised that you need a whole extra computer running Linux just to get started. As it ships without a system image, you need another computer running Linux to flash a fresh system image on to the Coral Dev Board. While not everyone will have a spare Linux computer just hanging around, fortunately it is entirely possible to use a Raspberry Pi for the task.
But you are also going to need a bunch of cables.
You’ll two micro-USB to USB-A cables; the first to power your Raspberry Pi, and the second to connect your Raspberry Pi to the Dev Board’s serial port. Additionally you’ll need a USB-A to USB-C cable to connect the Raspberry Pi to the Dev Board’s data port.
You’ll of course need a USB power adaptor to power your Raspberry Pi, and a micro SD Card for the Raspberry Pi’s system image.
If you want to connect your Linux computer, and the Coral Dev Board, to a wired — rather than wireless — network, you’ll also need two Ethernet cables.
Finally you’ll need a USB-C charger, and a USB-C to USB-C cable, to power the Dev Board.
While you might be able to get away with another USB-A to USB-C cable and a ‘normal’ USB charger to power the Coral Dev Board instead of a USB-C power supply, my experience with the Raspberry Pi suggests that most USB chargers aren’t rated, and will have some problems supplying, enough current.
While the Raspberry Pi needs a 2.5A power supply, the Coral Dev Board specifications say that it might well need more, from 2 to 3A. So I’m more that somewhat wary about trying a substitution, as I’ve got a sneaking suspicion that most if not all old style USB chargers won’t be up to powering the Dev Board.
I also wouldn’t try powering the Dev Board from your computer, even if you have a new MacBook with the appropriate USB-C sockets, as the datasheet explicitly warns against it. Presumably for very good reasons.