Post 'SD Card Backer Upper'

_posts/2021-03-27-sd-card-backer-upper.md

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+---
+layout: post
+title: "Automatic SD Card Backer Upper"
+---
+# Automatic SD Card Backer Upper
+
+I play on my DSi a lot, and i have all of my cartridges dumped to an SD card
+so I don't need to carry them with me to switch games. All my saves are stored
+on the SD card too, and sometimes I worry about the card getting corrupted or
+lost. So I used my Raspberry Pi to easily back it up. All I have to do is plug
+the card into the Pi, and it copies the files into a new folder and toggles a
+light when its done.
+
+## What I used:
+ * SD Card adapter
+ * USB mouse that I didn't care about
+ (any usb device that can light up will work)
+ * Raspberry Pi 3
+ (any raspberry pi with a USB connection and 3.5mm jack will work)
+  
+I did this on Ubuntu, but the instructions should work for Raspbian as well.
+
+## Files
+
+I made a few files for this to work: a udev rule file, a systemd unit, and a
+shell script.
+
+### Udev Rule
+```
+# /etc/udev/rules.d/999-automount.rules 
+ACTION=="add", SUBSYSTEM=="block", ENV{ID_SERIAL_SHORT}=="000000000828", RUN+="/usr/bin/systemctl start DSi.service"
+```
+You'll have to modify the `000000000828` to match the serial of your device,
+which you can get by plugging in the device, finding its /dev file, and running
+`udevadm info /dev/sdx | grep ID_SERIAL_SHORT`.
+
+### Systemd Service
+```
+# /etc/systemd/system/DSi.service
+[Unit]
+Description=back up dsi sd
+[Service]
+ExecStart=/home/ubuntu/autocopy.sh
+[Install]
+```
+There's nothing in the `[Install]` section because this isn't made to be enabled
+with `systemctl enable`, just executed with `systemctl start`, which the udev
+rule will do automatically. You'll want to modify the `ExecStart` line to point
+to your shell script.
+
+### Shell Script
+```
+#!/bin/sh
+# /home/ubuntu/autocopy.sh
+TIME=$(TZ=EST date +%F_%T) # used for folder name
+LABEL=DSi # the label of the SD cards filesystem
+MNT=/home/ubuntu/dsimnt # mount point of the sd card
+BACKUPDIR=/home/ubuntu/DSi # main directory all backups go to
+USBDEV=/sys/bus/usb/devices/1-1.5 # the sysfs entry for the usb device to use as a light
+
+# turn on the "led indicator" thats really a usb mouse torn apart
+echo 1 > ${USBDEV}/authorized
+mount "/dev/disk/by-label/${LABEL}" ${MNT}
+mkdir "${BACKUPDIR}/${TIME}"
+cp -r ${MNT}/* ${BACKUPDIR}/${TIME}/
+umount ${MNT}
+echo "done! you can remove the card."
+# turn that mouse back off
+echo 0 > ${USBDEV}/authorized
+```
+You'll want to change the `LABEL` variable to whatever the label of your SD card
+filesystem is.
+
+You will probably want to change the `TZ=EST` inside the `TIME` variable unless 
+you happen to live on the eastern coast of the United States.
+
+The mount point in the `MNT` variable is where the SD card should mount, which
+can be anywhere.
+
+The `BACKUPDIR` variable should be on a separate drive unless you have a 
+decently sized microSD inside your Pi that you don't mind filling up.
+
+The `USBDEV` variable is the path to your USB "light" inside 
+`/sys/bus/usb/devices`. You can run `lsusb` to get the ID of the usb device,
+then `cat` the `idProduct` and `idVendor` files inside each usb device folder
+until you find the one that matches your usb device.
+
+## Final Product
+
+What you'll have is something you can plug your SD card into and have a backup
+taken automagically. The light turns on when it's copying files, and turns off
+and unmounts the card when its done.
+You can see [a video of it working](/assets/sdcardpithing.mp4) here. Excuse the
+mess :) To access these backups, just go to the backup directory.
+
+![image](/assets/sdcardfolder.png)