Loading and updating a firmware

A can-enocean is updated over the boat's CAN bus, from the Brain, without opening anything and without a programmer. How that works — the anatomy of an image name, what must line up, what an interrupted upload leaves behind — is the same for every MUXEN box and is described in Loading and updating a firmware.

This page is what is particular to a can-enocean.

Which image goes in which box

One board and one application, so one image:

010010033-app_sfsp_enocean-firmware.srec

There is no board tag in the name, because there is only one board. Both of the things that must line up — the signature and the product ID — are checked by the box itself before anything is started.

Save the configuration first

The pairing list is the commissioning of a can-enocean: 63 slots, each holding the identifier of one switch, matched to the position that switch controls. Nothing on the boat rebuilds it for you and there is no undo. Read it out and keep the file:

muxen-uds -i can0 -d <address> readconfig --save-as-json before.json

Plan on re-applying it afterwards, and check the instance number came back with it:

muxen-uds -i can0 -d <address> writeconfig --from-json before.json

Doing the update

muxen-uds -i can0 listfirmware
muxen-uds -i can0 -d <address> firmware --name 010010033-app_sfsp_enocean-firmware.srec

While it runs the box is out of service: it stops publishing, and every switch behind it disappears from the boat's screens. Expect that, and do not do it under way.

What a failed update leaves behind

Two different failures, with two different outcomes.

An upload that stops early — a cable pulled, a Brain that reboots, a bus quiet for more than five seconds — leaves the spare slot visibly unfinished, and the bootloader ignores it. The box comes back on the firmware it already had, undamaged. Check that first:

muxen-uds -i can0 -d <address> readconfig --only-name SoftwareVersion

If it answers, nothing is lost. Work out which of the two alignments was wrong, pick the matching image, and try again.

An image that is complete, correctly signed, and then misbehaves stays. A can-enocean image is confirmed when it is built, not after it has proved itself running, so there is no automatic return to the previous version — see the table in Loading and updating a firmware. Recovering means uploading a good image over it, which works as long as the box still answers on the bus.