Not fully about pimatic related but I hope that here someone will know a fix for my issue. I’ve got a Synology 716+II NAS with 3 USB 3.0 ports and I’ve connected an arduino with 433MHz receiver/transmitter attached to it and homeduino as software. After installing the correct drivers it shows up under /dev/ttyUSB0.

The problem is that it takes a few minutes for the device to empty it’s buffers so pimatic will first give a timeout issue when I switch on a light and after a few minutes (usually around 5) it will flip the switch to reflect changes. This is also reflected when looking at the output for pimatic which is something like (pseudo):

<current time> - Send command “on” to “light”

  • wait some time…-
    <5min later> - “ACK”
    <5min later> - “PING”
    <5min later> - “PING”
    <5min later> - “PING”

I’m not really into (serial) hardware but for me it looks like somewhere the system is waiting for some buffer to fill up and flushed when full. When slightly modifying the homeduino code to output “PING” on every 10000th iteration so it will output a lot more data pimatic works without any issue and changes are displayed instantly. This confirms my theory on the buffer.
I’ve also tried different USB ports and included a USB 2.0 hub but the results stayed the same.

My question: is anyone familiar with this issue about some buffer that I have to lower (perhaps with some stty config command) to make sure it will work without pushing a lot of useless PINGs over the line?