On Friday 28 November 2014 05:33:48 [email protected] wrote: > C3-Wireless has developed a fully 802.3af-compliant PoE cape as part of an > internal project. We are trying to determine if there is enough demand to > release it as a commercial product. We would need to build a minimum of > 1000 units to make the price affordable. Do you think crowd-funding would > be a good approach? I'd love some feedback at [email protected]. > (Mods, please delete if you consider this spam. Thanks.) > > Casey > > On Wednesday, May 14, 2014 3:18:25 AM UTC-4, Christian wrote: > > Can BeagleBone Black only be powered by using PoE? In my project I want to > > avoid using too many cables. So the possibilty to use one cable for power > > and data would be very interesting. In this case a network switch would be > > working as an injector. The BeagleBone Black would only receive power from > > the Ethernet Port without using the 5V DC Port or microUSB Port. If PoE is > > not available by default, are there possibilties to upgrade by using a > > cape > > or an additional circuit? Remember that there are two forms of PoE. One is the full architected 802.3af version, which is 48V with a handshake to establish things like current requirement, and then there is the simpler "passive" PoE which just pushes typically 12-24V over the power pins (+ is 4-5, - is 7-8).
The PoE pins on the BBB (if I remember correctly) are not used as PoE and are either grounded or connected to ground by a resistor, either way no use. However you can get PoE injectors such as:- http://www.rfelements.com/en/products/power-over-ethernet/passive-poe/ The one on the left would be used to power a BBB and the one on the right would be used to inject the 5VDC into the cat-5 cable. However be careful as voltage drop across cat5 is bigger than one might imagine, so you would be better putting 12VDC into the injector and then connecting a 12V - 5V converter (either a car USB adapter or one of the little DC-DC converter modules) and pluging that into the BBB as it will be a "better" 5VDC. David -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
