Hi, Thanks for the help before. I've encountered problem while upload sketch to Arduino on UDOO x86 with Ubuntu. The upload always failed, it seems to be /dev/ttyACM0 permission issue while uploading. So I did some search, and there's a way to fix it. Here's my solution: 1. create a file under /etc/udev/rules.d, I use "52-arduino101.rules" 2. Content as below, replace the owner attribute with your user name Code: SUBSYSTEM !="usb_device", ACTION !="add", GOTO="arduino101_rules_end" ATTRS{idVendor} =="8087", ATTRS{idProduct} =="0ab6", MODE="0666", OWNER="name", GROUP="root" ATTRS{idVendor} =="8087", ATTRS{idProduct} =="0aba", MODE="0666", OWNER="name", GROUP="root" LABEL="arduino101_rules_end" 3. sudo udevadm trigger Then upload should be working now. Have fun.