<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">Hi Julian, All,</span></div><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><br></span></div><div>I think I've figured out the [gpio] external. It works fine, but there there is no documentation, however, the .c file is not very complicated.</div><div><br></div><div>The test-gpio.pd file is not very good as documentation, so I am attaching a draft help file. </div><div><br></div><div>The argument of [gpio] is the pin number. The first thing to do is [enable 1( and not [open 1(, which is equivalent to the:</div><div>sudo echo "17" > /sys/class/gpio/export</div><div>command.</div><div><br></div><div>Then [open 1(, then [output 1/0( to choose direction and then write (float) to or read (bang) from the pin...</div><div><br></div><div>There are still a few more things I need to discover, but more tomorrow when I have some jumper cables and feel more awake.</div><div><br></div><div>best,</div><div><br></div><div>J</div><div><br></div><div></div></body></html>