This system records video/stills of nesting garden birds. Although the complete system could be categorised as "video" the Picaxe part of the system is concerned with battery conservation.
This bird box includes a Raspberry Pi, camera and an 08m2 Picaxe, and is powered by a 12V 12Ahr battery. If the system was continuously powered, it may run for 80-100hrs before the battery would require recharging. However, the Picaxe controller only draws around 12mA, and monitors activity at the entrance to the box. When activity is detected, the Picaxe turns on Pi powered supply allowing the system to record video.
When activity stops, the Pi continues to run for a short time before being shutdown by the Picaxe. This considerably increases the period between recharging, especially during the early weeks of the nesting season, when birds are just checking out the box, or building a nest.
While the Pi is running, the Picaxe sends battery voltage readings to the Pi via a serial link. If the battery voltage falls below a set minimum limit, the Picaxe will not power the Pi until the battery has been recharged.
Since the Pi is equipped with WiFi and runs a VNC server, ongoing changes may be made to the Pi software. The Picaxe can also be re-programmed "in-circuit" from the Pi.
More details: http://captainbodgit.blogspot.co.uk/2015/12/birdbox2016-role-of-picaxe.html
This bird box includes a Raspberry Pi, camera and an 08m2 Picaxe, and is powered by a 12V 12Ahr battery. If the system was continuously powered, it may run for 80-100hrs before the battery would require recharging. However, the Picaxe controller only draws around 12mA, and monitors activity at the entrance to the box. When activity is detected, the Picaxe turns on Pi powered supply allowing the system to record video.
When activity stops, the Pi continues to run for a short time before being shutdown by the Picaxe. This considerably increases the period between recharging, especially during the early weeks of the nesting season, when birds are just checking out the box, or building a nest.
While the Pi is running, the Picaxe sends battery voltage readings to the Pi via a serial link. If the battery voltage falls below a set minimum limit, the Picaxe will not power the Pi until the battery has been recharged.
Since the Pi is equipped with WiFi and runs a VNC server, ongoing changes may be made to the Pi software. The Picaxe can also be re-programmed "in-circuit" from the Pi.
More details: http://captainbodgit.blogspot.co.uk/2015/12/birdbox2016-role-of-picaxe.html