Raspi example

[PatrickLang]

PR description

This merges in a community sample for using the library on a Raspberry Pi, along with a test cross build using GitHub Actions which are free for public open source repos. This was based on a sample shared in #48 which worked well for me.

What do you think about the organization? I can add a few more missing details on how to wire up the lcd and do other cleanup if needed.

Work remaining

• [x] CircleCI build step for this sample
• [x] Ensure this sample uses the current version of ssd1306 from this repo, not an older released version

Other checks

• [x] Check that you've added documentation to any new methods
• [x] Rebase from master if you're not already up to date
• [ ] Add a CHANGELOG.md entry in the Unreleased section under the appropriate heading (Added, Fixed, Changed, etc)
• [x] Run rustfmt on the project with cargo fmt --all - CI will not pass without this step
• [x] Check that your branch is up to date with master and that CI is passing once the PR is opened

Not applicable

• [ ] Add or modify an example if there are changes to the public API

[jamwaffles]

Thanks for the PR! I think the example might be better placed under examples/raspi as opposed to the current top-level examples-raspi. I'd also prefer not to use two different CI pipelines, so if you're familiar with CircleCI please move the build there. If not, I can take a look at adding the cross based build into CircleCI for you.

[PatrickLang]

Sure will update the layout and take a look at circleci. I have used it before

[PatrickLang]

I changed the paths, but still need to add CircleCI. I should be able to do that by end of week.

[PatrickLang]

@chux0519 - does this look ok to you? I just added more details in the readme. I think my OLED pinout matches yours but I wanted to double check.

I will do the circleCI update soon

[chux0519]

@PatrickLang It's been a while since I wrote that, and all code looks good to me. I think as long as the pipeline passed(not breaking current version), it should be ok

[PatrickLang]

Sorry it took me a bit to get back to this. I've been fighting with Jenkins in my day job and haven't been in the mood to work on CI at home ;) I got the sample up to the current library revision and it builds in CircleCI.

Just a note - you may want to move the other build steps to cimg/rust which will supercede circleci/rust

[patricklangsonos]

Thanks! I need to pull my Raspberry Pi back out and make some updates. I put this on hold for a while to work on other projects but may need it again soon.