I've set up a Yun before to use the handshake line on pin 7 (thanks to this great forum post) and now I have a new project that I want to do something similar with the Tian. Based on the schematic, it's a similar idea: set the output, mark the output low. But so far I haven't been able to get it working. Anyone know how to adopt the following command from /etc/rc.local to the Tian?
# Added section to set the handshake line. # GP19 is connected to D7 of the 32U4 processor. # This requires setting GP22 high to enable the U7 level shifter. # This GPIO is already exported. # Then GP19 needs to be exported, set to output, and finally brought low. echo 1 > /sys/class/gpio/gpio15/value echo 21 > /sys/class/gpio/export echo "high" > /sys/class/gpio/gpio21/direction echo 0 > /sys/class/gpio/gpio21/value
This code is what I'm using now: it's the forum poster's text with my updates for the Tian.