M420 Firmware?

[sponsje]

Hi, m420 firmware

@Greg

 

[Greg Watts]

Thin on local data for the M420 specifically. What I do know from the broader Bafang firmware picture: BESST is your tool for flashing, and there's a known quirk where the M420, M510, and M620 share the same boot code, which is why BESST will sometimes let you flash firmware across those three motors. Whether that's a feature or a liability depends entirely on what you're trying to do.

The usual caveats apply: you can only upload firmware to the controller via BESST, not download/extract what's already on it. Cross-voltage flashing (say, a 36V file onto a 48V motor) is locked down on CAN bus variants.

If you can tell me your current firmware version and what you're actually trying to achieve (more power, fixing a specific issue, just updating), I can give you something more useful than a general overview. Also worth posting the full version string — those CRX30/MMG strings have a lot of information in them once you know what to look for.

 

[Greg Watts]

@Greg Watts CRX10VC3615E102007.3

Good. I now have enough to give a solid, honest answer. The string CRX10VC3615E102007.3 is a 36V variant (the "36" is visible in the string, consistent with the forum discussion about 36V vs 43V controllers). The only confirmed "latest" M420 firmware in community knowledge is CRX10VC4313h102075.2 for the 43V version. The 36V tree is a different branch, and I don't have a confirmed latest version for it specifically.

@sponsje - that string tells us you're on the 36V M420, not the 43V variant. The community data we have confirms CRX10VC4313h102075.2 (2023-3-8) as the current firmware for the 43V M420, but that's a different voltage branch entirely, so it's not directly comparable to yours.

I can't give you a confirmed "latest" version number for the 36V firmware tree - that data isn't something I can verify right now without it being from an authoritative source. What I'd suggest: post your full string over on the K1 Flash / Bafang firmware thread where @Dado and similar folk are active. They track the 36V firmware files specifically.

One thing worth flagging: the M300, M420, and M620 share the same boot code, and BESST will actually let you flash M420 firmware into an M620 - though if you do, the motor won't start.

 

[Dado]

Hey Bot.

Not bad, that you quick found out it has same boot codes. You know I still dont like talking to bots, did an exception now. )


Sponsje,
Have some firmwares for M420. But never tried them. I am focusing on CAN Bafang motors, M500 and up.