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package gpio
import (
"gobot.io/x/gobot"
)
const (
MAX7219Digit0 = 0x01
MAX7219Digit1 = 0x02
MAX7219Digit2 = 0x03
MAX7219Digit3 = 0x04
MAX7219Digit4 = 0x05
MAX7219Digit5 = 0x06
MAX7219Digit6 = 0x07
MAX7219Digit7 = 0x08
MAX7219DecodeMode = 0x09
MAX7219Intensity = 0x0a
MAX7219ScanLimit = 0x0b
MAX7219Shutdown = 0x0c
MAX7219DisplayTest = 0x0f
)
// MAX7219Driver is the gobot driver for the MAX7219 LED driver
//
// Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf
type MAX7219Driver struct {
pinClock *DirectPinDriver
pinData *DirectPinDriver
pinCS *DirectPinDriver
name string
count uint
connection gobot.Connection
gobot.Commander
}
// NewMAX7219Driver return a new MAX7219Driver given a gobot.Connection, pins and how many chips are chained
func NewMAX7219Driver(a gobot.Connection, clockPin string, dataPin string, csPin string, count uint) *MAX7219Driver {
t := &MAX7219Driver{
name: gobot.DefaultName("MAX7219Driver"),
pinClock: NewDirectPinDriver(a, clockPin),
pinData: NewDirectPinDriver(a, dataPin),
pinCS: NewDirectPinDriver(a, csPin),
count: count,
connection: a,
Commander: gobot.NewCommander(),
}
/* TODO : Add commands */
return t
}
// Start initializes the max7219, it uses a SPI-like communication protocol
func (a *MAX7219Driver) Start() (err error) {
a.pinData.On()
a.pinClock.On()
a.pinCS.On()
a.All(MAX7219ScanLimit, 0x07)
a.All(MAX7219DecodeMode, 0x00)
a.All(MAX7219Shutdown, 0x01)
a.All(MAX7219DisplayTest, 0x00)
a.ClearAll()
a.All(MAX7219Intensity, 0x0f)
return
}
// Halt implements the Driver interface
func (a *MAX7219Driver) Halt() (err error) { return }
// Name returns the MAX7219Drivers name
func (a *MAX7219Driver) Name() string { return a.name }
// SetName sets the MAX7219Drivers name
func (a *MAX7219Driver) SetName(n string) { a.name = n }
// Connection returns the MAX7219Driver Connection
func (a *MAX7219Driver) Connection() gobot.Connection {
return a.connection
}
// SetIntensity changes the intensity (from 1 to 7) of the display
func (a *MAX7219Driver) SetIntensity(level byte) {
if level > 15 {
level = 15
}
a.All(MAX7219Intensity, level)
}
// ClearAll turns off all LEDs of all modules
func (a *MAX7219Driver) ClearAll() {
for i := 1; i <= 8; i++ {
a.All(byte(i), 0)
}
}
// ClearAll turns off all LEDs of the given module
func (a *MAX7219Driver) ClearOne(which uint) {
for i := 1; i <= 8; i++ {
a.One(which, byte(i), 0)
}
}
// sendData is an auxiliary function to send data to the MAX7219Driver module
func (a *MAX7219Driver) sendData(address byte, data byte) {
a.pinCS.Off()
a.send(address)
a.send(data)
a.pinCS.On()
}
// send writes data on the module
func (a *MAX7219Driver) send(data byte) {
var i byte
for i = 8; i > 0; i-- {
mask := byte(0x01 << (i - 1))
a.pinClock.Off()
if data&mask > 0 {
a.pinData.On()
} else {
a.pinData.Off()
}
a.pinClock.On()
}
}
// All sends the same data to all the modules
func (a *MAX7219Driver) All(address byte, data byte) {
a.pinCS.Off()
var c uint
for c = 0; c < a.count; c++ {
a.send(address)
a.send(data)
}
a.pinCS.On()
}
// One sends data to a specific module
func (a *MAX7219Driver) One(which uint, address byte, data byte) {
a.pinCS.Off()
var c uint
for c = 0; c < a.count; c++ {
if c == which {
a.send(address)
a.send(data)
} else {
a.send(0)
a.send(0)
}
}
a.pinCS.On()
}
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