I want my Raspberry Pi-based Little Backup Box to be simple and reliable. So I prefer not to tweak and enhance it too much. I do make occasional exceptions to that rule, though. Case in point, a Little Backup Box fork by David Mathias that has a few interesting features, including a progress indicator.
Raspberry Pi gives you only two LEDs (one on Raspberry Pi Zero) that you can use for visual feedback. Of course, you can hook up additional LEDs and even a screen, but if you prefer to keep things simple, two LEDs is all you’ve got. David came up with a rather ingenious solution to the problem: indicate the progress using the ACT LED blink rate–the fewer files remain to be transferred the faster the LED blinks.
The way this feature is implemented is pretty clever, too. During the backup, the script runs a loop that calculates the percentage of already transferred files in relation to the number of files on the storage card. If the percentage value is under 50%, then the LED blinks at the 300µs rate. When the value is more than 50% but less than 75%, the blink rate is 200µs. And when the value is over 75%, the blink rate changes to 100µs.
Of course this solution offers a rough approximation, but in most situations it’s all you need.
You’ll find the latest version of Little Backup Box in the project’s GitHub repository. To learn how to install, configure, and use Little Backup Box, get your copy of the Linux Photography book through Gumroad or Google Play Store.