KT Display Speed ?

[qwerkus]

Hello,

I'm trying to adapt a uart code to display the correct speed value of my controller on the KT display. Unfortunately, results are not great. Since I kept getting weird numbers, I wrote a loop trying every number from 0 to 255 and send it over via Byte 4 to the display. It appears I can only show speed numbers between 22 and 79. Maybe Byte 3 has to be set, but that doesn't seem to work. Has anyone experience with KT protocol that could help ?

Thank you very much,

Felix

 

[stancecoke]

Has anyone experience with KT protocol that could help ?

The Kunteng protocol is well known.
The speed has to be transmitted as the duration of one wheel revolution in milliseconds in 16 bit resolution, where byte 3 is the Hi-byte and byte 4 is the Lo-byte.
There are several open source implementations of the Kunteng protocol:
https://github.com/EBiCS/EBiCS_Firm...11c0224509a0274d32/Src/display_kunteng.c#L115

And of course you must calculate the checksum properly for each new value...

regards
stancecoke

 

[qwerkus]

The Kunteng protocol is well known.
The speed has to be transmitted as the duration of one wheel revolution in milliseconds in 16 bit resolution, where byte 3 is the Hi-byte and byte 4 is the Lo-byte.
There are several open source implementations of the Kunteng protocol:
https://github.com/EBiCS/EBiCS_Firm...11c0224509a0274d32/Src/display_kunteng.c#L115

And of course you must calculate the checksum properly for each new value...

regards
stancecoke

Yes, that's the code I'm using for my script. I got the revolution period, but not the 16 bit resolution; was wondering why you'd need 2 bytes though... Thank you very much for you explanation now it works!

 

[qwerkus]

The Kunteng protocol is well known.
The speed has to be transmitted as the duration of one wheel revolution in milliseconds in 16 bit resolution, where byte 3 is the Hi-byte and byte 4 is the Lo-byte.
There are several open source implementations of the Kunteng protocol:
https://github.com/EBiCS/EBiCS_Firm...11c0224509a0274d32/Src/display_kunteng.c#L115

And of course you must calculate the checksum properly for each new value...

regards
stancecoke

Is it usual that the display takes so long to compute speed value at startup ? I timed 31s from the moment I power the display up to the correct speed value... Tested with a KT LCD8 and a LCD4