BLDC controller Communication Protocol of Speed Data

[avd4]

Hello,

I read the relevant topics in the forum, but I couldn't get the result I wanted.

I have an e-bike BLDC controller(I guess it has XCM microcontroller), made in China, without documentation. I don't know if it would be OK to share a link, you know, it is with metallic gray boxes one. I can view speed data with the LCD screen. How can I find out which communication protocol is used during this data transmission? I can understand that mostly UART is used. I hope to understand the incoming data with a MCU. I plan to reverse engineering using CH340 and digital oscilloscope but I would be very happy if anyone with previous experience could help. So, yes, I know what I what to do, but I haven't seen any users achieving any successful results.

Thank you for your tolerance and answers.

 

[amberwolf]

UART is just a hardware device or a definition of a way of sending serial data. Some systems misuse the word to mean two-wire serial data vs one-wire serial data or LIN or CANbus, etc.

Protocol and data formats and even voltages used can be anything.

What did you need the speed data for, and what other data do you need from it?

If you only need speed data, it is MUCH simpler to simply read the speed sensor directly via whatever system you want it for; it's just pulses on a single wire in the system. Depending on the system it's for, there is probably a dedicated sensor and signal wire for this (though most of the DD hubmotor systems use one of the hall signals present for motor position sensing).

If you need other data from the system, it may be worth decoding the protocol.

There are a number of threads around the forum that discuss some of them, and some have a little info in them. There are also the various open-source firmwares here on ES and Github and the like for some controllers and some displays that may have other info as well.