Size of uart rx_buffer_size

[Sleeper85]

Hi @syssi

For my YamBMS project where UART ports are preconfigured, I would like to increase the rx_buffer_size value to 1024.

What would be the impact of doing this with your jk_bms component over UART ?

The goal would be to have a buffer size that can work with both JK-B and JK-PB (RS485).

Thanks for your help

[syssi]

IMO there is no impact. The cell info frame must fit into the buffer (once!). If you increase the buffer the memory will be reserved but never used.

[Sleeper85]

And if the buffer is too small, what happens ?

@txubelaxu RS485 component uses a rx_buffer of 1000 by default.
Unfortunately, I don't have a JK-PB to do the tests. I wonder if his component could work with a rx_buffer of 512?

I have someone who uses my project with 7x JK-PB, I can ask him to do some tests.
I also wonder if having 7x JK-PB requires a bigger rx_buffer than with 1x JK-PB ?

I would like to find a value that can fit both components without choosing 1024 if it is not necessary.

[syssi]

If the RX buffer is too small the component won't be able to decode incoming frames (which exceeds the size of the buffer).

[Sleeper85]

Ok so the problem will be visible directly, it remains to be seen whether the size of this frame increases with the number of BMS used (a single UART connection with RS485).

[syssi]

I don't understand your last statement. Why do you expect the frame length increases with the number of devices?

[Sleeper85]

This is a question I ask myself.

Does the size of this frame increase with the number of BMS to supervise? Retrieving information from 7x JK-PB (on the same RS485 links) is 7x more information. But maybe @txubelaxu code makes a request for each BMS and the frame keeps the same size...

I don't have a JK-PB to check this, the easiest thing is to ask someone to test it for me.