I've been trying to set up the Meraki Sparky board to flash the openwrt code to it, but when I connect the pins and plug in the usb adapter to my laptop and run the meraki-flasher script, I get this exception "SerialException('device reports readiness to read but returned no data (device disconnected?)')" and the green led on the meraki board isn't lit.  But $ dmesg | grep tty shows that it's connected.