KindleCron - cron-like task scheduling that survives deep sleep

KindleCron (kcron)

KindleCron runs scheduled jobs on a jailbroken Kindle reliably and to the second,
while letting the device sleep between them. It is a single static binary with no
dependencies.


Features

• Full cron expressions (5- or 6-field, optional seconds), plus one-shot once schedule
• Survives suspend via powerd's rtcWakeup; no need to keep the device awake
• Optional keep-awake for sub-minute jobs, with a battery warning
• Per-job timeout; a hung job is killed and can never pin the device awake
• Catches up on runs missed while the device was off
• Optional KUAL menu

Tested on
Kindle Basic 10th gen (KT4, FW 5.13.6) and Paperwhite 4 (PW4, FW 5.17.1.0.3). Other
jailbroken models with the same powerd service should work - reports welcome.

Requirements
A jailbroken Kindle. KUAL is optional (you can run the binary directly).

Install
Download the latest release, unzip, connect over USB, and copy the extensions
and kcron folders to the root of the Kindle drive.


Source & releases

GitHub: https://github.com/lennardollesch/KindleCron

The RTC-wakeup approach is based on yparitcher's thread and the powerd
documentation comes from the KindleModding project - thanks to both.
Feedback and reports of additional working models are welcome.