UART vs CAN comma protocol

Barnsleyrob

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Jul 20, 2020
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I was interested to read on another thread that UART based ebikes can’t use 3rd party batteries without the right chip or a workaround dongle.

I’ve got a Pinnacle Mercury which uses a Bafang hub motor and a Taiwanese battery. Bafang sent me the user guide for the handlebar control unit in both UART and CAN protocols. The UART version (which I have) is basically pretty dumb compared to the CAN version. In particular the battery gauge isn’t linear whereas the CAN version works as I would expect where each of the 5 segments represents 20% capacity (on the UART, one segment can represent anything between 30 to 10%).

So my question is can you really not recall a UART based unit or was the comment specific to the Haibike/Yamaha unit that was the subject of the other thread.
 

Barnsleyrob

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Jul 20, 2020
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This is the post I was referring to.
 

soundwave

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GLJoe

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I was interested to read on another thread that UART based ebikes can’t use 3rd party batteries without the right chip or a workaround dongle.

... UART and CAN protocols....
UART/CAN/Whatever - this is just referring to the fact that there is the potential for data communication. It doesn't tell you anything about how or what has been implemented on a particular bike.

So some bikes motors/controllers do indeed refuse to work unless they can perform a data handshake with a genuine battery. With others, this isn't the case.
So ignore any threads dealing with different models and instead seek out info specific to the exact system you want to find out about.
 

Barnsleyrob

Pedelecer
Jul 20, 2020
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UART/CAN/Whatever - this is just referring to the fact that there is the potential for data communication. It doesn't tell you anything about how or what has been implemented on a particular bike.

So some bikes motors/controllers do indeed refuse to work unless they can perform a data handshake with a genuine battery. With others, this isn't the case.
So ignore any threads dealing with different models and instead seek out info specific to the exact system you want to find out about.
It’s a Pinnacle Mercury 2021 from Evans Cycles. Do you know much about them ? Only info I found is that the pedals go round and round.
 
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Nealh

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Uart uses simple comms and only the display & controller communicate with each other, RX/TX comms are the normal used. It means that one can't mix n match controllers /displays from other brands.
Battery wise one can usually any generic battery if the wiring is simple two wires.

CANbus if a different kettle of fish and all part of the electronics handshake with each other, it means a battery is expensive as is the sytem should it go wrong.
 

GLJoe

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May 21, 2017
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Uart uses simple comms and only the display & controller communicate with each other, RX/TX comms are the normal used. It means that one can't mix n match controllers /displays from other brands.
Battery wise one can usually any generic battery if the wiring is simple two wires.

CANbus if a different kettle of fish and all part of the electronics handshake with each other, it means a battery is expensive as is the sytem should it go wrong.
It would be really good to have a bit more clarification on what you've just written.
I suspect you are probably correct in the context of some Bafang options, but as its written, someone just reading it as is could get a little confused (as I am reading what you've written!)
A system with a UART can be designed have a horrendously complex comms system and could talk to the battery as well if it wanted.
A CANbus system can be very simple.
UART is just the name for the hardware device that handles Received (RX) and transmitted (TX) data.
CAN just stands for Controller Area Network. Its just a different protocol. What it actually does can drastically vary depending on the manufactures implementation.

I don't know what someone like Bafang does with their different systems, so it would be good to differentiate between protocols and actual implementations.
 
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soundwave

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