The DRB III reads to 0.1 degrees, though the sensors might be capable of more. I did play around with them some more and took some measurements against a digital inclinometer I have and the output appears to be linear. And I was wrong before, it's actually 6 byte output, which is pretty crazy resolution, though I'm not sure if the sensors can actually really read that reliably or not. The DRB also reads things as -180 to +180, so I need to do some testing on "negative" outputs to confirm how they work. Need to check on the zero function as well. It's easy enough to do in software (just apply an offset), but I don't know if the DRB actually sends a command to the sensors and the zero is stored internally on them or if it's just handled purely on the DRB III.
I thought about it some more, did a little testing, and I'm pretty sure I can actually power the system from a computer USB as well. Though the DRB powers the switch box with 12v, there is a 5v regulator inside it that runs pretty much everything else. The DRB also only outputs 5v on the line it uses to switch between left and right sensors. I realized a 5v regulator doesn't have to have 12v fed to it to work, it just wants 5 or more.
So my plan at the moment is a custom cable that would plug into the switch box on one end and the other end will have a DB9 connector, a switch, and a USB connector. The USB is there strictly for power and pulls 5v from the computer to run things. The switch will let you toggle back and forth between reading the right or left sensor (I'm not sure a good way to automate this just yet so both can be read at once like the DRB III does). This way you wouldn't have to fiddle around with a separate power supply or two cables or anything like that. Messed with it a bunch yesterday and was having a hard time understanding the cable, but I think it finally hit me what I was doing wrong, so planning to take another stab at it today. If the cable and power part is solved I just have to figure out the software side, which is going to be a little more interesting. The actual functional side of the program is pretty dirt simple, it's just a matter of figuring out what to code it in and how to talk to a serial port. I have very little experience with talking to hardware on Windows based computers, but I'm hoping I can make something work.
On a different note, any chance you could measure that tool up once you get it? I'm pretty sure the only difference between left and right are the hooks, so would think if you have one you could make another pretty easily by just mirroring things. If you can measure the main block part I think it would be really easy to recreate and I'd be interested in trying to make one myself. As for sensors, I'm pretty sure that tool is aluminum, so don't think a magnetic one is going to do you much good. Most of the ones I see are longer and meant to be more like a level, which isn't really that useful here. The factory ones are pretty compact and nicely machined to be square. There might be something out there though, I just haven't looked that much. The ones I have came in an alignment kit I got as a Christmas present a few years ago. They are more like the level style though and pretty long.
