mqtt_pi_led-display/src/controller.py

import paho.mqtt.client as mqtt

import time
import board
import busio
from adafruit_ht16k33 import segments
from enum import Enum

__TOPIC_BRIGHTNESS__ = "brightness"
__TOPIC_SCROLL_INTERVAL__ = "scrollinterval"
__TOPIC_TEXT_STATIC__ = "textstatic"
__TOPIC_TEXT_ONCE__ = "textonce"
__TOPIC_TEXT_SCROLL__ = "textscroll"
__TOPIC_TEXT_SCROLL_REPEAT__ = "textscrollrepeat"
__TOPIC_TEXT_SCROLL_LR__ = "textscrolllr"

NUMDIGITS = 8

class Mode(Enum):
	STATIC = 1 #show text constantly. may cut digits
	ONCE = 3 #show once for some time
	SCROLL = 2 #scroll thorugh once
	SCROLL_LR = 4 #scroll back and forth
	SCROLL_REPEAT = 5

class Controller:
	connected = False
	displayL = None
	displayR = None
	last_scrollupdate = 0
	mode = Mode.STATIC

	def __init__(self, base_topic, mqtt_host, mqtt_port = 1883):

		self.scroll_interval = 0.25
		self.text = "    "
		self.poscount = 0
		
		# Create the I2C interface.
		self.i2c = busio.I2C(board.SCL, board.SDA)
		
		# Create the LED segment class.
		# This creates a 14 segment 4 character display:
		self.displayL = segments.Seg14x4(self.i2c, address=0x70) # find address with "sudo i2cdetect -y 1"   . you need to install: sudo apt-get install -y python-smbus i2c-tools
		self.displayR = segments.Seg14x4(self.i2c, address=0x71)
		
		# Clear the display.
		self.displayL.fill(0)
		self.displayR.fill(0)
		
		# set brightness, range 0-1.0, 1.0 max brightness
		self.displayL.brightness = 1.0
		self.displayR.brightness = 1.0
		
		self.mqtt = mqtt.Client()
		self.mqtt.on_connect = self.on_connect
		self.mqtt.on_message = self.on_message
		self.mqtt.on_disconnect = self.on_disconnect
		self.mqtt.connect(mqtt_host, mqtt_port)
		self.topic = base_topic
		
		self.displayL.print("LEFT")
		self.displayR.print("RIGH")


	def on_disconnect(self, client, userdata, rc):
		print("MQTT disconnected")
		self.connected = False

	def on_message(self, client, userdata, message):
		msg = str(message.payload.decode("utf-8"))
		print("msg = " +  msg)
		
		if message.topic.endswith(__TOPIC_BRIGHTNESS__ + "/set"):
			val = float(msg)
			if val >= 0.0 and val <=1.0:
				self.displayL.brightness = val
				self.displayR.brightness = val
				print("changed brightness to ", self.displayL.brightness)
				self.mqtt.publish(self.topic + "/" + __TOPIC_BRIGHTNESS__, self.displayL.brightness, 1 )
			else:
				print("invalid brightness ", val)
		
		if message.topic.endswith(__TOPIC_SCROLL_INTERVAL__ + "/set"):
			val = float(msg)
			if val > 0.0:
				self.scroll_interval = val
				print("changed scroll_interval to ", self.scroll_interval)
				self.mqtt.publish(self.topic + "/" + __TOPIC_SCROLL_INTERVAL__, self.scroll_interval, 1 )
			else:
				print("error not >0.0: ", val)
		
		
		if message.topic.endswith(__TOPIC_TEXT_SCROLL_REPEAT__ + "/set"):
			self.mode = Mode.SCROLL_REPEAT
			self.poscount = 0 #start at beginning of new text
			self.text = msg
			if len(self.text)==0:
				self.text="    "
			print("changed text to ", self.text)
			self.mqtt.publish(self.topic + "/" + __TOPIC_TEXT_SCROLL_REPEAT__, self.text, 1 )
			
		if message.topic.endswith(__TOPIC_TEXT_SCROLL_LR__ + "/set"):
			self.mode = Mode.SCROLL_LR
			self.poscount = 0 #start at beginning of new text
			self.text = msg
			if len(self.text)==0:
				self.text="    "
			print("changed text to ", self.text)
			self.mqtt.publish(self.topic + "/" + __TOPIC_TEXT_SCROLL_LR__, self.text, 1 )


	def on_connect(self, client, userdata, flags, rc):
		print("Connected to MQTT Broker")
		self.mqtt.subscribe(self.topic + "/#")
		self.connected = True

	def displayTextOffset(self, _text, _offset = 0, _wrap=True):
		while len(_text)<NUMDIGITS:
			_text+=" "
			
		if _wrap:
			self.displayL[0] = _text[((_offset+0)%len(_text))]
			self.displayL[1] = _text[((_offset+1)%len(_text))]
			self.displayL[2] = _text[((_offset+2)%len(_text))]
			self.displayL[3] = _text[((_offset+3)%len(_text))]
			self.displayR[0] = _text[((_offset+4)%len(_text))]
			self.displayR[1] = _text[((_offset+5)%len(_text))]
			self.displayR[2] = _text[((_offset+6)%len(_text))]
			self.displayR[3] = _text[((_offset+7)%len(_text))]
		else:
			if _offset+0>=0 and _offset+0<len(_text):
				self.displayL[0] = _text[((_offset+0))]
			if _offset+1>=0 and _offset+1<len(_text):
				self.displayL[1] = _text[((_offset+1))]
			if _offset+2>=0 and _offset+2<len(_text):
				self.displayL[2] = _text[((_offset+2))]
			if _offset+3>=0 and _offset+3<len(_text):
				self.displayL[3] = _text[((_offset+3))]
			if _offset+4>=0 and _offset+4<len(_text):
				self.displayR[0] = _text[((_offset+4))]
			if _offset+5>=0 and _offset+5<len(_text):
				self.displayR[1] = _text[((_offset+5))]
			if _offset+6>=0 and _offset+6<len(_text):
				self.displayR[2] = _text[((_offset+6))]
			if _offset+7>=0 and _offset+7<len(_text):
				self.displayR[3] = _text[((_offset+7))]

	def loop_forever(self):
		run = True

		while run:
			self.mqtt.loop(0.1) #with block timeout

			if self.displayL is not None and self.displayR is not None: #displays initialized
				if self.mode == Mode.SCROLL_REPEAT:
					if time.time() > self.last_scrollupdate+self.scroll_interval: #time to update animation
						self.displayTextOffset(self.text, self.poscount, True)
						
						self.poscount += 1
						self.poscount %= len(self.text)
						self.last_scrollupdate = time.time()
						
				if self.mode == Mode.SCROLL_LR:
					if time.time() > self.last_scrollupdate+self.scroll_interval: #time to update animation
						print("pos=", self.poscount)
						scrolloffset = self.poscount
						if scrolloffset >= (len(self.text)-NUMDIGITS):
							scrolloffset = (len(self.text)-NUMDIGITS) - (scrolloffset-(len(self.text)-NUMDIGITS)) #reverse
						scrolloffset = max(0,scrolloffset) #cap at zero
						print("scrolloffset=", scrolloffset)
							
						self.displayTextOffset(self.text, scrolloffset, False)
						
						self.poscount += 1
						self.poscount %= (len(self.text)-NUMDIGITS)*2 #if poscount over scrollable width means scroll backwards 
						self.last_scrollupdate = time.time()