Thanks for the feedback. I think for my purposes a simple buffer will work[now that I know how they work].
I want to attatch 2 BBB's to each other in a master/slave setup, so to stack them on top of each other means the board needs to reverse the P8/P9 headers[I'd make the board bigger than the BBB so the 2 sets of header attachments are offset and connections can be made between them]. I assume it is safe to tie the GROUND pins of each board directly to each other. Wheras the 3V and 1.8V power rails should not connect. The 5V pin from the master should connect to the 5V pin on the child to power it. For that, an i2c --> parallel latch can be used to enable a transistor after the Master boots in order to power up the Slave. Beyond that, around 8GPIO pins connecting one board to the other is all I need. So a couple of buffers for each direction can be used to connect them, and the same i2c-->parallel chip can be used to enable the chip. I figure if I get to the point of actually making a board for the device, I might as well throw some extra buffers on there to allow additional GPIO's to connect - my driver can simply not enable them, but someone else might want to use them and can go through and enable them in 8 pin blocks. The one exception for my purposes is that all the GPMC pins should map to each other without buffers to avoid timing issues. I want to play with connecting a camera cape to both boards at the same time. The slave board has a single job: processing the video stream, saving each frame out to permanent storage. The master board will only read about 5-6 FPS for "preview" mode. All in all, I think that by repurposing a lot of the software written for the Elphel, an open source camera can be put together for under $250 - which makes it much more accessible for hacking. At the same time, it would have lots of things which could be "improved" - ie replace the second BBB with the upcoming FPGA cape. Many options to swap the sensor for a better one either by replacing just the sensor[if pin compatible] or creating a new sensor connection board. If done right, it should even be possible to use a USB webcam instead of the cam cape, and run both the master and slave software on a single board. I can't imagine doing that for practical usage, but if someone just wanted to contribute a better user interface or additional jimage macro's, they can do so by purchasing just a single BBB. -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
