I'm very inexperienced with the RS-485(Half-duplex) and in Yocto/Linux and could use some guidance.
The board I'm using is :https://www.avalue.com.tw/Product/RISC-Platform/Single-Board-Computer/SBC/ACP-IMX6POS_2201
By using the supplier specific files, with small modifications in the .dtb files(just to add rs485 at boot for uart). I can successfuly send simple data with echo from another computer which supports RS-485 natively by echoing into that serial interface and with : cat /dev/ttymxc2 on my board. I cannot send data from my board.
However, why I try to send a file from my other computer with zmodem a few unreadble bits appear and then it crashes.
Before we get to techical I would like to ask a few simple questions.
1. Is it possible, or rather feasible to send files over RS-485 without any further protocol? (If not, how should it be done?).
2. My board only has support for kernel 3.14.28 which by reading on different forums doest not support RS-485. Yet I'm able to read RS-485 data. Why is that?
3. Do i need to manually upgrade the kernel to 4.1x before trying to implement further solutions?
Would be really thankful for help!