SwiftyTM1637

A SwiftyGPIO based driver for the TM1637 7-segment chipset, as used in the LK-Digi LinkerKit element.

The module is heavily inspired by the Python code example shown at the LK-Digi wiki.

Example

A simple digital clock:

import Foundation
import SwiftyGPIO
import SwiftyTM1637

let gpios   = SwiftyGPIO.GPIOs(for: .RaspberryPi3)

// E.g. a LK-Digi connected to the P4/P5 digital pins
let display = TM1637(clock: gpios[.P4]!, data: gpios[.P5]!)

display.turnOff()
display.brightness = .typical

while true {
  let cal = Calendar.current
  let now = cal.dateComponents([.hour, .minute, .second], from: Date())
  
  let hour   = now.hour   ?? 0
  let minute = now.minute ?? 0
  let second = now.second ?? 0
  
  let segment2 = SevenSegment(digit: hour % 10, dot: second % 2 != 0)
  
  display.show(s1: hour   / 10, s2: segment2,
               s3: minute / 10, s4: minute % 10)
  
  Thread.sleep(forTimeInterval: 0.5)
}

How to setup and run

Note: This is for 32-bit, 64-bit doesn’t seem to work yet.

Raspi Docker Setup

You don’t have to, but I recommend running things in a HypriotOS docker container.

Setup is trivial. Grab the flash tool, then insert your empty SD card into your Mac and do:

$ flash --hostname zpi3 \
  https://github.com/hypriot/image-builder-rpi/releases/download/v1.8.0/hypriotos-rpi-v1.8.0.img.zip

Boot your Raspi and you should be able to reach it via zpi3.local.

I also recommend to use docker-machine (e.g. see here), but that is not necessary either.

Running an ARM Swift container

Boot the container like so:

$ docker run --rm \
  --cap-add SYS_RAWIO \
  --privileged \
  --device /dev/mem \
  -it --name swiftfun \
  helje5/rpi-swift-dev:4.1.0 /bin/bash

You end up in a Swift 4.1 environment with some dev tools like emacs pre-installed. Sudo password for user swift is swift.

Creating a small clock

In the container:

swift@fb630076e0ec:~/testit$ mkdir testit && cd testit && swift package init --type executable
Creating executable package: testit
Creating Package.swift
Creating README.md
Creating .gitignore
Creating Sources/
Creating Sources/testit/main.swift
Creating Tests/

Then edit the Package.swift file to look like this:

// swift-tools-version:4.0

import PackageDescription

let package = Package(
    name: "testit",
    dependencies: [
        .package(url: "https://github.com/uraimo/SwiftyGPIO.git",
                 from: "1.0.0"),
        .package(url: "https://github.com/SwiftyLinkerKit/SwiftyTM1637.git",
                 from: "0.1.2"),
    ],
    targets: [
        .target(
            name: "testit",
            dependencies: [ "SwiftyTM1637", "SwiftyGPIO" ]),
    ]
)

Edit the Sources/testit/main.swift and add the Swift code above.

Build everything:

swift@fb630076e0ec:~/testit$ swift build
Fetching https://github.com/uraimo/SwiftyGPIO.git
Fetching https://github.com/AlwaysRightInstitute/SwiftyTM1637.git
Cloning https://github.com/uraimo/SwiftyGPIO.git
Resolving https://github.com/uraimo/SwiftyGPIO.git at 1.0.5
Cloning https://github.com/SwiftyLinkerKit/SwiftyTM1637.git
Resolving https://github.com/SwiftyLinkerKit/SwiftyTM1637.git at 0.1.0
Compile Swift Module 'SwiftyGPIO' (10 sources)
Compile Swift Module 'SwiftyTM1637' (4 sources)
Compile Swift Module 'testit' (1 sources)
Linking ./.build/armv7-unknown-linux-gnueabihf/debug/testit

You need to run it using sudo, password is swift:

swift@fb630076e0ec:~/testit$ sudo .build/armv7-unknown-linux-gnueabihf/debug/testit

If your LK-Digi is connected to port D4/D5, it should now show a nice digital clock!

Want to see it in action? SwiftyGPIO driven input/output using LinkerKit components

Who

SwiftyTM1637 is brought to you by AlwaysRightInstitute. We like feedback, GitHub stars, cool contract work, presumably any form of praise you can think of.

There is a channel on the Swift-ARM Slack.