When I declared Sawppy the Rover has reached version 1.0 and posted instructions online, I was fully aware of the fact that the instructions would be incomplete. Not out of neglect or malice, but out of the fact all of Sawppy is in my head and there will be places where I decided something was obvious enough not to require documentation – and learn I was wrong in that judgement.

Such is the case now. One member of RSSC accepted my invitation to build a Sawppy after my presentation in January, and submitted the feedback that I need to post a schematic of how I’ve wired up Sawppy. I previously submitted this answer as response to a comment on this Hackaday.io project page, but more detail was needed.

The minimum electronics components for a bare-bones Sawppy has [10 * LewanSoul LX-16A] wired in parallel with each other and to [1 * LewanSoul “BusLinker” a.k.a. “Debug Board”] to translate generic USB serial to servo half-duplex serial. That translator board is connected to [1 * Raspberry Pi] via USB.

I thought this was a good opportunity to try Scheme-It from Digit-Key. It is a web-based electronics schematic editor that purports to let people quickly sketch up electronics schematics for sharing. The electrical wiring for a bare-bones Sawppy version 1.0 should be a nice easy exercise for this tool.

The terms and conditions for using Scheme-It is fairly typical for a web-based application. A Digi-Key account is required for login, something I already had from earlier purchases for electronics experiments. In exchange for free use of the software, a user also has to grant Digit-Key a license to the schematic. Not a big deal in this case, as I wanted Sawppy to be shared as widely as possible. And finally, Digi-Key reserves the right to take down this service at any time, deleting all of my data. This is irritating but not unexpected. If this is important to me I better make a copy for my own storage.

Since my sample schematic is fairly simple, it only took about an hour to go from absolute beginner to the schematic I wanted to create. I could (and did) choose to share the project file publicly via a URL, though it appears accessing the project requires logging in to Scheme-It, which required a Digi-Key account as previously mentioned. I could also export to PDF or PNG formats. The PDF export feature was unsatisfactory. Many labels were moved out-of-place making the schematic illegible. In contrast the PNG export looks OK so I’ve posted this schematic PNG to the files section of this project page, as well as Sawppy’s assembly instructions hosted on Github.

(Cross-posted to NewScrewdriver.com)