mirror of https://github.com/kidoman/embd
86 lines
2.2 KiB
Go
86 lines
2.2 KiB
Go
/*
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* Copyright (c) Clinton Freeman 2017
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
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* associated documentation files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge, publish, distribute,
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* sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies or
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* substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
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* NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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package apa102
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import (
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"github.com/cfreeman/embd"
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)
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const (
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MAX_BRIGHTNESS = 31
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)
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type APA102 struct {
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Bus embd.SPIBus
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LED []uint8
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nLED int
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}
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func New(bus embd.SPIBus, numLEDs int) *APA102 {
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res := &APA102{
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Bus: bus,
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LED: make([]uint8, numLEDs*4),
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nLED: numLEDs,
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}
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// Init the intensity field for each LED which is
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// 0b111 + 5 intensity bits.
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for i := 0; i < (numLEDs * 4); i = i + 4 {
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res.LED[i] = 224
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}
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return res
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}
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func (a *APA102) SetLED(index int, r uint8, g uint8, b uint8, i uint8) error {
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intensity := i
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if i > 31 {
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intensity = 31
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}
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ind := index * 4
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a.LED[ind+0] = 224 + intensity // Brightness is 0b111 + 5 intensity bits
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a.LED[ind+1] = b
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a.LED[ind+2] = g
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a.LED[ind+3] = r
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return a.Show()
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}
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func (a *APA102) Show() error {
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// Start frame is 32 zero bits.
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err := a.Bus.TransferAndReceiveData([]uint8{0, 0, 0, 0})
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// LED data.
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// 111+5bits(intensity) + 1byte(Red) + 1byte(Green) + 1byte(Blue)
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err = a.Bus.TransferAndReceiveData(a.LED)
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if err != nil {
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return err
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}
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err = a.Bus.TransferAndReceiveData([]uint8{1, 1, 1, 1})
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if err != nil {
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return err
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}
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return nil
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}
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