Comparing revisions for MiniCarComputer
- [1994] 2013-12-27 18:22:29 by KarlMW (unregistered user) [add some more power management ideas to consider]
- [1870] 2013-05-25 16:03:51 by KarlMW (unregistered user) [mostly power management notes]
Additions:
====__More Power Management Notes__====
- connection to host
- minimum requirements:
- 1 signal to rPi to indicate current main power status (car running or off)
- 1 signal from rPi to request shutdown
- digital I/O is simple to connect to rPi
- USB would allow more flexibility to use this board for other things
- sensing of the world
- main power status input
- pref via R network with some voltage limiting so that it could be used for 12V or 5V or something else
- pref with schmitt input or such so that it has sharply defined threshold and does not get upset by slowly dropping voltage
- optional bridge rectifier for sensing AC?
- optocoupled input for sensing AC mains?
- optional analog sensing so as to measure input voltage?
- space for small C for transient suppression (or could do this in software)
further options:
- measure car 12V voltage as well as own battery voltage?
- extra signal to rPi to indicate impending SLA battery failure and shutdown
- domestic usage
- control a mains relay (or SSR/triac) so that we can use it for a domestic device
- pref optocoupled for safety
- could have 2 controlled outputs so that it can manage its own mains as well as another device?
- mains power loss sensing?
- optional timer in PSU controller to restore power after "x" time period
- eg. to use for a device which powers on and runs a scheduled backup of something every day
- connection to host
- minimum requirements:
- 1 signal to rPi to indicate current main power status (car running or off)
- 1 signal from rPi to request shutdown
- digital I/O is simple to connect to rPi
- USB would allow more flexibility to use this board for other things
- sensing of the world
- main power status input
- pref via R network with some voltage limiting so that it could be used for 12V or 5V or something else
- pref with schmitt input or such so that it has sharply defined threshold and does not get upset by slowly dropping voltage
- optional bridge rectifier for sensing AC?
- optocoupled input for sensing AC mains?
- optional analog sensing so as to measure input voltage?
- space for small C for transient suppression (or could do this in software)
further options:
- measure car 12V voltage as well as own battery voltage?
- extra signal to rPi to indicate impending SLA battery failure and shutdown
- domestic usage
- control a mains relay (or SSR/triac) so that we can use it for a domestic device
- pref optocoupled for safety
- could have 2 controlled outputs so that it can manage its own mains as well as another device?
- mains power loss sensing?
- optional timer in PSU controller to restore power after "x" time period
- eg. to use for a device which powers on and runs a scheduled backup of something every day