Scrolling Text sensor node with new V_TEXT

  • Hero Member

    Another experiment for the V_TEXT variable/ sensor. Including brightness & speed setting and special Alarm function.
    A scrolling display to let the family now that the dog needs walking... nothing more than 1 nano, 8 (or whatever number) of displays with max7219 controller upload-f2290f64-a15d-48c9-8420-ab65e481a492 a radio and a few cables
    Total cost: €18 (with 8 displays)

    in Domoticz:
    Built around the very versatile "Parola" driver library

    (I will upload a video when I know how to .. ;-))
    MySensors - Scrolling text display – 00:05
    — Ad Imhoff

     PROJECT: MySensors / Scrolling Text display
     DATE: september 12, 2015/ last update: september 12, 2015
     FILE: AWI_scroll_MAX.ino
     LICENSE: Public domain
     Hardware: tbd ..Ceech - ATmega328p board w/ NRF24l01
    	and MySensors 1.5 ()
    	Need to use MySensors development edition 
    	3 S_xx devices for scrolling text
    	- Displays a scrolling text from a "V_TEXT" variable
     	- additional dimmer sensor for controlling display brightness
    	- 'Alarm' switch. If "On", overrides the text display to display ALARM message
    	- You can also input messages from the Serial monitor (testing)
    	Uses excellent MD_MAX72XX library 
    	Fixed node-id
    // Use the MD_MAX72XX library to scroll text on the display with the use of the callback function 
    // to control what is scrolled on the display text.
    // You need to set the used display in the library MD_MAX72XX.h
    // User can enter text on the serial monitor and this will display as a
    // Speed for the display is controlled by a pot on SPEED_IN analog in.
    #include <MD_MAX72xx.h>						// multipurpose library for MAX72xx diaplay driver
    #include <MySensor.h>          				// Mysensor network
    #include <SPI.h>
    #include <Time.h>   						//
    #define	USE_POT_CONTROL	0					// enable Scroll speed  potentiometer
    #define	PRINT_CALLBACK	0
    // Macro to simplify serial print
    #define	PRINT(s, v)	{ Serial.print(F(s)); Serial.print(v); }
    // Define the number of devices we have in the chain and the hardware interface
    // need to be adapted to your setup
    const int MAX_DEVICES = 8 ;					// number of 8x8 displays
    const int CLK_PIN = 7 ; 					// SPI like clock
    const int DATA_PIN = 8 ;					// SPI like data
    const int CS_PIN = 6 ; 						// SPI like select
    // Parola is able to use SPI hardware interface, not testted in combination with MySensors
    // now use Arbitrary pins
    MD_MAX72XX mx = MD_MAX72XX(DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);	// instantiate one display chain
    // Scrolling parameters, you can attach normal potentiometer to A5, Vcc, Gnd
    const int SPEED_IN = A5 ;
    const int SCROLL_DELAY = 20 ;				// in milliseconds
    #endif // USE_POT_CONTROL
    const int CHAR_SPACING = 1 ;				// pixels between characters
    // MySensors constants & variables
    const byte nodeId = 51 ;					// MySensors fixed node id
    const byte messageCHILD = 8 ;				// Text from ControllerLCD
    const byte brightnessChild = 9 ;			// Brightness of display
    const byte alarmChild = 10 ;				// Display Alarm text (overrides normal text)
    boolean timeReceived = false ;				// Flag to indicate time received
    // Display constants & variables
    byte textBrightness = 1 ;					// brightness of display (between 0 - MAX_INTENSITY (0xF)
    byte textOnOff = true ;						// textOnOff = ! shutdown
    boolean textAlarm = false ;					// Alarm (switch S_BINARY)
    // Global message buffers shared by MySensors and Scrolling functions
    const int BUF_SIZE = 25 ;					// max payload for MySensors(NRF24l01)
    char curMessage[BUF_SIZE];					// current displayed message
    char newMessage[BUF_SIZE];					// next message to be displayed if available
    bool newMessageAvailable = false ;			// new message available flag
    uint16_t	scrollDelay;					// in milliseconds
    // *** Definition and initialisation
    // define the MySensor network (1.5)
    MyTransportNRF24 transport(9,10); 			// Sensoduino (8,7) Ceech board, 3.3v (7,8)  (pin default 9,10)
    MySensor gw(transport);  
    // Initialize messages for sensor network
    MyMessage textMsg(messageCHILD, V_TEXT);	// message for Sending Text to Controller
    /* MD_MAX72XX functions: can be found in the documentation for the library,
     * no need to customtize callback & scroll routines (unless you want to...)
    uint8_t scrollDataSource(uint8_t dev, MD_MAX72XX::transformType_t t)
    // Callback function for data that is required for scrolling into the display
      static char		*p = curMessage;
      static uint8_t	state = 0;
      static uint8_t	curLen, showLen;
      static uint8_t	cBuf[8];
      uint8_t colData;
      // finite state machine to control what we do on the callback
        case 0:	// Load the next character from the font table
          showLen = mx.getChar(*p++, sizeof(cBuf)/sizeof(cBuf[0]), cBuf);
          curLen = 0;
          // if we reached end of message, reset the message pointer
          if (*p == '\0')
            p = curMessage;			// reset the pointer to start of message
            if (newMessageAvailable)	// there is a new message waiting
              strcpy(curMessage, newMessage);	// copy it in
              newMessageAvailable = false;
          // !! deliberately fall through to next state to start displaying
        case 1:	// display the next part of the character
          colData = cBuf[curLen++];
          if (curLen == showLen)				// end of character insert interchar space
            showLen = CHAR_SPACING;
            curLen = 0;
            state = 2;
        case 2:	// display inter-character spacing (blank column)
          colData = 0;
          if (curLen == showLen)
            state = 0;
          state = 0;
    // Callback (not used here)
    void scrollDataSink(uint8_t dev, MD_MAX72XX::transformType_t t, uint8_t col){
    // Callback function for data that is being scrolled off the display
    	Serial.print("\n cb ");
    	Serial.print(' ');
    	Serial.print(' ');
    // non-blocking text display to be used in loop (call frequently)
    void scrollText(void){
    	static uint32_t	prevTime = 0;
    	if (millis()-prevTime >= scrollDelay){					// Is it time to scroll the text?
    		mx.transform(MD_MAX72XX::TSL);						// scroll along - the callback will load all the data
    		prevTime = millis();								// starting point for next time
    // sets the scroll delay (read from potentiometer if enabled)
    uint16_t getScrollDelay(void){
    	uint16_t t = analogRead(SPEED_IN);
    	t = map(t, 0, 1023, 25, 250);
    void setup(){
    	// set up the display first
    	mx.begin();												// initialize display chain					
    	mx.setShiftDataInCallback(scrollDataSource);			// define function to get the scrolldata (returned as int8)
    	//mx.setShiftDataOutCallback(scrollDataSink); 			// not used
    	mx.control(MD_MAX72XX::INTENSITY, 0x01);
    #if USE_POT_CONTROL											// initialize speed potentiometer if enabled
    	pinMode(SPEED_IN, INPUT);
    	scrollDelay = SCROLL_DELAY;
    	strcpy(curMessage, "I \x03 MySensors ");				// first message on display
    	newMessage[0] = '\0';									// new message initialized to empty
    	// Setup MySensors 
       //Serial in Sensor network = 115200
        gw.begin(incomingMessage, nodeId); 						// this node is 51 fixed 
        //Send the sensor node sketch version information to the gateway
        gw.sendSketchInfo("AWI Scroll MAX 51", "1.1");
     	gw.present(messageCHILD, S_INFO, "Text line Scroll");	// new S_type 20150905 (not know by domoticz)
     	gw.present(alarmChild, S_BINARY, "Alarm display");		// to display alarm text
    	gw.present(brightnessChild, S_DIMMER, "Text brightness"); // new S_type 20150905 (not know by domoticz)
        //gw.send(textMsg.set("-"));							// initialize the V_TEXT at controller for sensor to none (trick for Domoticz)
    	gw.request(messageCHILD, V_TEXT, 0); 					// request value from controller
    	// Initializations
        gw.requestTime(receiveTime);							// get the time from controller (handled by receiveTime)
    // loop only uses non-blocking functions
    void loop() {
    	static unsigned long lastUpdate ;						// Static hold the last update time
    	unsigned long now = millis();
    	scrollDelay = getScrollDelay();							// update scroll delay from potentiometer
        // Check for new conditions & ask for new information from controller every 10 seconds
        if (now-lastUpdate > 10000){
    		if (textAlarm){										// if alarmstatus: override all text and set max intensity
    			strcpy(curMessage, "   ALARM   ");
    			mx.control(MD_MAX72XX::INTENSITY, MAX_INTENSITY);	// set current brightness
    			mx.control(MD_MAX72XX::SHUTDOWN, false) ;
    		} else {											// standard (non Alarm actions)
    			mx.control(MD_MAX72XX::INTENSITY, textBrightness);	// set current brightness
    			mx.control(MD_MAX72XX::SHUTDOWN, textOnOff) ;
    			gw.request(messageCHILD, V_TEXT, 0); 				// request new value from controller
    		lastUpdate = now;
    // This is called when a new time value was received
    void receiveTime(unsigned long controllerTime) {
        Serial.print("Time value received: ");
        setTime(controllerTime); 								// time from controller
        timeReceived = true;
    // This is called when a message is received 
    void incomingMessage(const MyMessage &message) {
    	Serial.print("Message: "); Serial.print(message.sensor); Serial.print(", Message: "); Serial.println(message.getString());
    	if (message.sensor == messageCHILD){
    		if (message.type==V_TEXT) {						// Text content
    		strcpy(newMessage, message.getString());		// copy it in
     			newMessageAvailable = true ;
    	} else if (message.sensor == alarmChild) {
    		if (message.type==V_STATUS) {					// True/ false content
     			textAlarm = message.getBool()?true:false ;	// set alarmflag
    			Serial.print("TextAlarm: ");
    	} else if (message.sensor == brightnessChild){
    		if (message.type==V_PERCENTAGE) {				// Level 0..100  content
     			textBrightness = map(message.getInt(),0, 100, 0, MAX_INTENSITY ) ;	// map to brightnesslevel 
    			Serial.print("TextBrightness: ");
    		} else if (message.type==V_STATUS) {			// Display on/off
     			textOnOff = message.getBool()?false:true ;		// set shutdown/ !on/off
    			Serial.print("Text on/off: ");
    // Testing purposes: input routine character buffer. Reads serial characters in buffer newMessage.
    // sets flag newMessageAvailable to true if completed
    void readSerial(void)
      static uint8_t	putIndex = 0;
      while (Serial.available())
        newMessage[putIndex] = (char);
        if ((newMessage[putIndex] == '\n') || (putIndex >= BUF_SIZE-3))	// end of message character or full buffer
          // put in a message separator and end the string
          newMessage[putIndex++] = ' ';
          newMessage[putIndex] = '\0';
          // restart the index for next filling spree and flag we have a message waiting
          putIndex = 0;
          newMessageAvailable = true;
          // Just save the next char in next location

  • Admin

    Wow, cool @AWI

  • Wow, thats great !

    Could you please post an AliExpress link to the displays you used ?


  • Wow, I so want to build this!

  • Hero Member

    @billy123 That would be the right one. You can use most of the max7219 driven display. Sometimes these are 90 deg rotated but that can be adjusted in the library. Have fun!

  • Will this work in Vera??

  • Hero Member

    @Hoffan I don't know the abilities of VERA but since this (V_TEXT) is new functionality I expect it works only in Domoticz. I hope the functionality will be extended to the other controllers soon..

  • Thanx for the answer, I hope that too

  • Plugin Developer

    found this library for scrolling effect

  • Hero Member

    @Dheeraj I have tried this library also but it did not suit my purpose. Only one type of display orientation is supported but it is easier to comprehend.

  • Umm, this is awesome! Looks like I have a tinker project coming up!

  • Looks great. Is it posible (Or do you think it will be) to sen dynamic values to the display from Domoticz? Like the temperature or soil moist procentage.

  • Hero Member

    @popunonkok it is very possible. In fact this is what I'm doing. You need to work on the controller side. For domoticz you can use a lua time script which sends new text every x time. For long messages you will need to script a fifo with multiple text messages.

  • Hardware Contributor

    Is it possible to send text to the node without a request call from the node itself?

    The example is not clear on this point and the json example only sets the text value within Domoticz, right?

  • Hero Member

    @GertSanders Domoticz does not "push" the Text value when changed. The published sketch "asks" periodically for the Text value. What I do now is create a Switch (S_BINARY/ light) with function "New text available". This switch triggers the polling sequence.

  • Hardware Contributor

    @GizMoCuz : It would be nice to be able to define the text of the S_INFO sensor in de UI of Domoticz, instead of only via json. I'm not capable of programming that myself, but it would make the use of text easier. I already log all incoming SMS messages into my SMS connected sensor in V_TEXT and have it this way a nice view on what nodes are sending to my SMS passthrough node or what SMS messages are received into my MySensors network. I know Domoticz has it's own SMS interface, but my node is capable of switching on stuff based on directly received SMS commands, and with V_TEXT I can now follow what is happening without needing a serial connection to the node. I should be clear that I'm a big fan of Domoticz 🙂

  • Hero Member

    @Jager If your controller supports it you can. In Domoticz the text value is not pushed so you need to make a request for it.

  • What am i missing, Because i get this when i try to compile it

    Arduino:1.6.5 (Mac OS X), Kort:"Arduino Nano, ATmega328"

    ScrollingText:55: error: 'V_TEXT' was not declared in this scope
    ScrollingText.ino: In function 'void setup()':
    ScrollingText:166: error: 'S_INFO' was not declared in this scope
    ScrollingText:170: error: 'V_TEXT' was not declared in this scope
    ScrollingText.ino: In function 'void loop()':
    ScrollingText:191: error: 'V_TEXT' was not declared in this scope
    ScrollingText.ino: In function 'void incomingMessage(const MyMessage&)':
    ScrollingText:210: error: 'V_TEXT' was not declared in this scope
    'V_TEXT' was not declared in this scope

Log in to reply





Looks like your connection to MySensors Forum was lost, please wait while we try to reconnect.