# HG changeset patch # User Steve Losh # Date 1699209132 18000 # Node ID 1d91d45e243dcb914f25fc833c4a9bfe77251276 # Parent c8af1ec6611bf038f975a5e08928beabf4f125aa Update diff -r c8af1ec6611b -r 1d91d45e243d README.markdown --- a/README.markdown Fri Nov 03 13:35:51 2023 -0400 +++ b/README.markdown Sun Nov 05 13:32:12 2023 -0500 @@ -730,3 +730,58 @@ Did a bit of dotfile cleanup. Realized I can also sync `htoprc` which is nice. Also discovered `htop` has an option for highlighting new processes and recently-killed ones, which will be *really* handy. + +## 2023-11-04 + +Poking around at getting my Pine64 working again. Dug out what I think is power +suppy (5V 3A), and it seems to work, so that's good. Booted it with the tiny +screen and one of my old UHK's, but couldn't remember the password I had set +(and apparently I never bothered saving it in my password manager, which is +bizarre for me). Oh well, probably a good idea to do a fresh install of Armbian +on it anyway. Attempted this and no matter what I try, the board just doesn't +ever boot. Tried multiple different SD cards, no luck. Linux is such a goddamn +mess some times. + +Eventually I realized that I was trying to use the Pine64 images from Armbian +because the page is titled "Pine64 and LTS" and I have a Pine A64-LTS. But +apparently the A64-LTS needs to use the SOPINE images, even though I don't have +a SOPINE. Christ, what a mess. Got SSH set up, dotfiles synced easily. + +Starting to look at the GPIO stuff now. Useful links: + +* +* +* + +HelLEDo, world: + + echo 77 >/sys/class/gpio/export + cd /sys/class/gpio77 + echo 1 > direction + echo 1 > value + echo 0 > value + echo 77 >/sys/class/gpio/unexport + + (defparameter *f* + (open "/sys/class/gpio/gpio77/value" :direction :output :if-exists :supersede)) + (write-char #\0 *f*) + #\0 + (force-output *f*) + +Neat. Dug around and tried to figure out how to use hardware PWM, but the +documentation is… a mess, so I janked together PWM in software instead. That… +kind of worked. I (much) later realized the site that gave me the duty cycle +timings lied to me (it said 1ms-2ms when it's really much closer to 0.5ms-2.5ms +according the manufacturer). But even so, it's still really janky to try to +software PWM from an SBC, so everyone seems to recommend breaking out an Arduino +to make *that* control the servos, and then have the SBC drive that. Poked +around a bunch more and eventually got that working too. + +Next step is to get a web server running, which wasn't too hard with +Hunchentoot. Looked at various routing libraries and went with `easy-routes` +for now. Seems okay, though there are a few parts I don't love. But it's good +enough for now. And with that I can `curl` and move the arm. Neat. + +## 2023-11-05 + +HG545 review session.