raspi
Raspberry Pi scripts for various projects
init_sdcard.sh
This script pulls down the latest Raspbian, enables SSH, sets the hostname, optionally sets up wpa_supplicant.conf, and writes the image to the sdcard. I use it for preparing Pis for cluster duty as follows:
./init_sdcard.sh -a ~/.ssh/id_rsa.pub -d usb_device -e clusternet -g cpu -r mmc0 clusterpi{00..10}
This will prompt for the wifi password once and then prompt each time you need to switch the sdcard. Everything else is automagic. If you don't want to configure wifi, just leave off the -e flag.
setup_leds.sh
By default, the LEDs on the Pi 3B+ are solid red for power and flashing green for SD card (mmc0) activity. There are, however, quite a few things you can trigger on:
none rc-feedback kbd-scrolllock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock timer oneshot heartbeat backlight gpio [cpu] cpu0 cpu1 cpu2 cpu3 default-on input panic mmc1 mmc0 rfkill-any rfkill0 rfkill1
For reasons I don't fully understand, the red LED cannot be controlled as granularly as the green one. Basically red is on or off while green has variable brightness. To trigger the green activity LED on cpu utilization and the red power LED on sdcard activity for my cluster nodes:
./setup_leds.sh -g cpu -r mmc0 clusterpi{00.10}
By default, the LED settings will be reset to default at boot. If you want to persist in /boot/config.txt, just add the -p flag.
setup_docker.sh
./setup_docker.sh [-j manager] nodes
If you provide an existing manager (-j), then all nodes will be setup with Docker then join the provided manager's swarm as workers. If you don't provide an existing manager, then the first node passed in will initialize a new swarm as the lead manager and the remaining nodes passed in will be added to its swarm as workers.
water_the_plants.py
A simple polling app that measures soil moisture content using a ubiquitous soil sensor. The cool part is that it only powers up the sensor when actively polling, so you save power and the sensor should be slower to corrode since it's not generally acting as an electrode. If you care about power efficiency and you don't care about logging or remote control, you might be better off using a purpose built board as they're super cheap and much less power hungry than the Pi.