Deriving the regulated 5 VDC supply from 24 VDC can be a simple as a single pass-regulator with a couple of capacitors. Or you can make it more efficient by using a little switching-regulator chip. 0-24 volt DC inputs just take a resistor divider (two resistors) to scale the input range down to 0-1.8 VDC. That would work for both GPIOs and ADCs. For 24 volt high-side output I would use an opto-isolator (AKA solid state relay) for each output. You drive a transistor (like a 2N2222) with a couple of milliamps from a GPIO pin, and that drives the opto-isolator’s LED with the required 10-20 ma (too much for a BBB GPIO).
All of those could go on a cape, but if you need more than a few of those 24 volt outputs then you might run out of room. Adding more RAM is going to take a custom main board redesign because the processor’s DRAM interface signals are not present on the P8 and P9 connectors. From: Mark Zeilenga Sent: Thursday, February 20, 2014 12:28 PM To: beagleboard@googlegroups.com Subject: [beagleboard] BBB Hardware Modifications I have a potential application for a device like the BBB but it needs a few changes. I'm a software guy so I don't know if they are minor design changes or major. I work as an OEM in the manufacturing world. Most devices I deal with are 24v. So how difficult would it be do redesign the BBB to have the following: 1. 24v power source 2. 24v I/O 3. 1 to 2gb RAM I assume a nice cape could also be designed to bring the I/O into nice screw terminals too. I understand the BBB was not intended for this but it seems a pretty good starting point and I just wanted to know the feasability and potential cost of doing something like this. Mark -- 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. -- 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.
