7 segment LED

seven_seg.go

package main

import (
	"github.com/stianeikeland/go-rpio"
	"log"
	"time"
)

func main() {
	// TODO: Fix IO pins. Convert physical to gpio num.
	// https://github.com/stianeikeland/go-rpio/blob/master/rpio.go#L28
	// http://www.instructables.com/id/Controlling-a-7-segment-4-digit-display-with-a-Ras/
	// https://www.sengoku.co.jp/mod/sgk_cart/detail.php?code=EEHD-4KZB
	segments := []rpio.Pin{
		rpio.Pin(8),  // physical 24, CE0
		rpio.Pin(18), // physical 12, GPIO18
		rpio.Pin(10), // physical 19, MOSI
		rpio.Pin(9),  // physical 21, MISO
		rpio.Pin(11), // physical 23, SCLK
		rpio.Pin(25), // physical 22, GPIO25
		rpio.Pin(22), // physical 15, GPIO22
	}
	digits := []rpio.Pin{
		rpio.Pin(7),  // physical 26, CE1
		rpio.Pin(24), // physical 18, GPIO24
		rpio.Pin(23), // physical 16, GPIO23
		rpio.Pin(27), // physical 13, GPIO21 ?? Not connected! Should be GPIO27?
	}
	// Clickwise from top + middle
	// top, top right, bottom right, bottom, bottom left, top left, middle
	num := map[rune][]int{
		' ': {0, 0, 0, 0, 0, 0, 0},
		'0': {1, 1, 1, 1, 1, 1, 0},
		'1': {0, 1, 1, 0, 0, 0, 0},
		'2': {1, 1, 0, 1, 1, 0, 1},
		'3': {1, 1, 1, 1, 0, 0, 1},
		'4': {0, 1, 1, 0, 0, 1, 1},
		'5': {1, 0, 1, 1, 0, 1, 1},
		'6': {1, 0, 1, 1, 1, 1, 1},
		'7': {1, 1, 1, 0, 0, 0, 0},
		'8': {1, 1, 1, 1, 1, 1, 1},
		'9': {1, 1, 1, 1, 0, 1, 1},
	}
	dot := rpio.Pin(17) // physical 11, GPIO17
	dot.Output()
	dot.Low()

	err := rpio.Open()
	if err != nil {
		log.Fatal(err)
	}

	// TODO: What is this PullDown for?
	inPin := rpio.Pin(7)
	inPin.Input()
	inPin.PullDown()

	for _, segment := range segments {
		segment.Output()
		segment.Low()
	}

	for _, digit := range digits {
		digit.Output()
		digit.High()
	}

	defer rpio.Close()

	for {
		// TODO: Get string representation of number.
		s := "1234"

		// TODO: Loop through `digits`.
		// Draw each digit.
		for digitPos, digit := range s {
			for i, bit := range num[digit] {
				if bit == 0 {
					segments[i].Low()
				} else {
					segments[i].High()
				}
			}

			if digitPos == 1 {
				dot.High()
			} else {
				dot.Low()
			}

			digitPin := digits[digitPos]
			digitPin.Low()
			<-time.After(1 * time.Millisecond)
			digitPin.High()
		}
	}
}