This project deals with an innovative and visual method of conveying the message to the people using a wireless notice board which is developed using WiFi technology. This will help us show any electronic message almost immediately with negligible delay just by sending a short message from the mobile application. That is better and more reliable than the old traditional way of passing the news on the notice board.
In today’s world, mobile phones and related technologies are becoming more and more popular. Various technical arenas in the field of Telecommunication and Embedded Systems are becoming upright to the people. Notice boards are one of the widely used ones ranging from primary schools to significant organizations to convey messages to large groups of people. A lot of paper is being used and which is later just to get wasted. It leads to a lot of deforestation, thus leading to global warming. A small innovative step in making use of technology for regular purposes would have an adverse effect on the environmental issues with which we are presently concerned.
The aim of this project is how to make a web-controlled Wireless Notice Board using ESP8266 NodeMCU and Dot Matrix Display. In our project, the ESP8266 NodeMCU establishes a strong connection between a WiFi network and the board itself and generates a webpage given by a local IP address. Using the Web dashboard, we can send any message by just typing in the blank space. And the NodeMCU will display it on the Dot Matrix Display as well.
I will recommend you to check out our another IoT Projects.
Project
Circuit Diagram
Components Required
- ESP8266 NodeMCU
- 4:1 MAX7219 Dot Matrix Display
- 7805 Regulator
- Capacitor (10uF/16V, 100uF/25V)
- Connection Wire
- Veroboard
- 5 Volt Power Source
About Parts of the Wireless Notice Board
Dot Matrix Display
LED matrices are available in the market in different colours like single colour, dual colour, and RGB colour. They are also available in different dimensions like 5×7, 8×8, 16×16, 8×32, 32×32, and more.
This 8×32 LED Matrix Display is a multitude of 4 single Matrix Displays which are internally connected. These displays also have the ability to separate from each other, as every module carries the same Maxim MAX7219 chip, and can be connected with the same power and data connection. That’s why if any of the single displays get damaged, they will be easily replaceable.
MAX7219 LED Driver Chip
This Matrix Displays can be driven in two ways. One is a parallel way where the parallel data is sent to each row or column. The second one is the serial way where the data is sent serially and an IC is used to convert this serial data into parallel data.
MAX7219 is a common cathode display driver with serial input and parallel output. It is used to interface microprocessors and microcontrollers with 64 individual LEDs. The 8×8 LED matrix is connected to the MAX 7219. The data input is received from the Arduino board to the MAX7219.
PCB Design
After designing the schematic diagram of the Wireless Notice Board, the assembled components and wiring are too clumsy and looked very unprofessional. In fact, the wiring also has a chance of loose connection. To give it a clean and professional look and compress the size, I decided to build its PCB prototype using EasyEDA software as it is so simple to use. Now come to the main part, where we need to order our PCB prototype. I always prefer PCBWay for its quality assurance, fastest delivery, and 24/7 customer support.
PCB View
PCBWay is a Chinese-based PCB manufacturing company which is providing prototypes, PCB assembly, SMT Stencil and Flexible PCBs. I am in collaboration with them for about recent 1.5 years, and I feel like PCBWay gives an excellent price and customer service factor in one single serving. What is also spectacular about PCBWay to me, as an electronics hobbyist and customer, is their on-time service. In this review, I will explain my personal opinion regarding the quality and processing aspects of PCBWay.
When I first approached PCBWay, I found their PCB prototyping and customisation options capture huge areas with every aspect of you can customize the PCB as per your wish. You can choose different types of solder masks, silkscreen, surface finish, materials and much more. Below, I have attached some solder mask quality provided by PCBWay.
Addressing their SMT stencil service, it is often ordered with your standard PCB boards if your design includes surface mount components being soldered on. Really it is too professional and accurate also checked by their engineers. It is like a template which makes it easy for your project as surface mount soldering isn’t the easiest skill to grasp. Besides the prototype customization, PCBWay also offers different interchangeable options such as the stencil type, thickness, existing fiducials, whether you like electropolishing or not etc.
Now come to the PCB Assembly service, where components can be assembled by them, and your PCB board will come ready to be used. Also here you could choose the option to have PCBWay supply all the components on your design or have the option for your own where you need to supply all the components. Alternatively, you could choose the combo option where PCBWay supplies some parts, along with you will have to supply the rest of the components. I strongly recommend going for the combo option if you have some of the parts you need for that project.
The best part of PCBWay in my opinion, their engineers check your Gerber file and if there is a correction needed, they might contact you or correct it with their PCB expertise. Pointing to that, I think this is the most valuable service that they are providing you than other companies.
Now, once you have done all your customisations and made your final choices, you can receive a quote along with a rough price estimate directly from their website. The price of your product will be based on the options you choose, with the higher, more expensive options contributing to your price more heavily. Shipping is also included separately, DHL is the expensive method and standard airmail is the cheapest method of shipment. The nice thing about PCBWay’s website is that you can see how the final price is broken down by certain costs. Furthermore, there is a choice for you to select your build time and shipping method so that when you change it, you can instantly see the price difference.
Circuit Connection of Wireless Notice Board
The left side of the Dot Matrix Display is basically for the input pins which are connected to any GPIO pins of a microcontroller. Similarly, the right side of the display is the output port for adding additional displays.
From the left side, connect the VCC and GND of the Dot Matrix Display to the 3.3V and GND of the ESP8266 board. The default SPI and GPIO pins of the ESP8266 are being used to connect with each of the remaining SPI terminals of the MAX7219 display module. Therefore, connect the DIN, CS, and CLK pins to the ESP8266 board’s D7, D8, and D5 pins.
NodeMCU Code
To compile this below code, you have to install these two library files into your Arduino IDE.
After uploading the code to ESP8266, you can see the IP address on the Dot Matrix Display for entering the webpage.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 | #include <ESP8266WiFi.h> #include <MD_Parola.h> #include <MD_MAX72xx.h> #include <SPI.h> // Turn on debug statements to the serial output #define DEBUG 0 #if DEBUG #define PRINT(s, x) { Serial.print(F(s)); Serial.print(x); } #define PRINTS(x) Serial.print(F(x)) #define PRINTX(x) Serial.println(x, HEX) #else #define PRINT(s, x) #define PRINTS(x) #define PRINTX(x) #endif #define HARDWARE_TYPE MD_MAX72XX::FC16_HW #define MAX_DEVICES 4 //Maximum single module connected #define CS_PIN 15 // HARDWARE SPI MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES); // WiFi network SSID and Pass const char* ssid = "**********"; const char* password = "**********"; // WiFi Server object and parameters WiFiServer server(80); // Scrolling parameters uint8_t frameDelay = 25; // default frame delay value textEffect_t scrollEffect = PA_SCROLL_LEFT; // Global message buffers shared by Wifi and Scrolling functions #define BUF_SIZE 512 char curMessage[BUF_SIZE]; char newMessage[BUF_SIZE]; bool newMessageAvailable = false; const char WebResponse[] = "HTTP/1.1 200 OK\nContent-Type: text/html\n\n"; const char WebPage[] = "<!DOCTYPE html>" \ "<html>" \ "<center>" \ "<head>" \ "<title>Electro Gadget</title>" \ "<script>" \ "strLine = \"\";" \ "function SendData()" \ "{" \ " nocache = \"/&nocache=\" + Math.random() * 1000000;" \ " var request = new XMLHttpRequest();" \ " strLine = \"&MSG=\" + document.getElementById(\"data_form\").Message.value;" \ " strLine = strLine + \"/&SD=\" + document.getElementById(\"data_form\").ScrollType.value;" \ " strLine = strLine + \"/&I=\" + document.getElementById(\"data_form\").Invert.value;" \ " strLine = strLine + \"/&SP=\" + document.getElementById(\"data_form\").Speed.value;" \ " request.open(\"GET\", strLine + nocache, false);" \ " request.send(null);" \ "}" \ "</script>" \ "</head>" \ "<body>" \ "<p><font size=\"6\"><b>Wireless Notice Board</b></font></p>" \ "<form id=\"data_form\" name=\"frmText\">" \ "<label><font size=\"4\"><b>Type Your Message</b></font><br><input type=\"text\" name=\"Message\" maxlength=\"255\"></label>" \ "<br><br>" \ "<input type = \"radio\" name = \"Invert\" value = \"0\" checked> Normal" \ "<input type = \"radio\" name = \"Invert\" value = \"1\"> Inverse" \ "<br>" \ "<input type = \"radio\" name = \"ScrollType\" value = \"L\" checked> Left Scroll" \ "<input type = \"radio\" name = \"ScrollType\" value = \"R\"> Right Scroll" \ "<br><br>" \ "<label>Speed<br>Fast<input type=\"range\" name=\"Speed\"min=\"10\" max=\"200\">Slow"\ "<br>" \ "</form>" \ "<br>" \ "<input type=\"submit\" value=\"Send Data\" onclick=\"SendData()\">" \ "</body>" \ "</html>"; const char *err2Str(wl_status_t code) { switch (code) { case WL_IDLE_STATUS: return ("IDLE"); break; // WiFi is in process of changing between statuses case WL_NO_SSID_AVAIL: return ("NO_SSID_AVAIL"); break; // case configured SSID cannot be reached case WL_CONNECTED: return ("CONNECTED"); break; // successful connection is established case WL_CONNECT_FAILED: return ("CONNECT_FAILED"); break; // password is incorrect case WL_DISCONNECTED: return ("CONNECT_FAILED"); break; // module is not configured in station mode default: return ("??"); } } uint8_t htoi(char c) { c = toupper(c); if ((c >= '0') && (c <= '9')) return (c - '0'); if ((c >= 'A') && (c <= 'F')) return (c - 'A' + 0xa); return (0); } void getData(char *szMesg, uint16_t len) // Message may contain data for: // New text (/&MSG=) // Scroll direction (/&SD=) // Invert (/&I=) // Speed (/&SP=) { char *pStart, *pEnd; // pointer to start and end of text // check text message pStart = strstr(szMesg, "/&MSG="); if (pStart != NULL) { char *psz = newMessage; pStart += 6; // skip to start of data pEnd = strstr(pStart, "/&"); if (pEnd != NULL) { while (pStart != pEnd) { if ((*pStart == '%') && isxdigit(*(pStart + 1))) { // replace %xx hex code with the ASCII character char c = 0; pStart++; c += (htoi(*pStart++) << 4); c += htoi(*pStart++); *psz++ = c; } else *psz++ = *pStart++; } *psz = '\0'; // terminate the string newMessageAvailable = (strlen(newMessage) != 0); PRINT("\nNew Msg: ", newMessage); } } // check scroll direction pStart = strstr(szMesg, "/&SD="); if (pStart != NULL) { pStart += 5; // skip to start of data PRINT("\nScroll direction: ", *pStart); scrollEffect = (*pStart == 'R' ? PA_SCROLL_RIGHT : PA_SCROLL_LEFT); P.setTextEffect(scrollEffect, scrollEffect); P.displayReset(); } // check invert pStart = strstr(szMesg, "/&I="); if (pStart != NULL) { pStart += 4; // skip to start of data PRINT("\nInvert mode: ", *pStart); P.setInvert(*pStart == '1'); } // check speed pStart = strstr(szMesg, "/&SP="); if (pStart != NULL) { pStart += 5; // skip to start of data int16_t speed = atoi(pStart); PRINT("\nSpeed: ", P.getSpeed()); P.setSpeed(speed); frameDelay = speed; } } void handleWiFi(void) { static enum { S_IDLE, S_WAIT_CONN, S_READ, S_EXTRACT, S_RESPONSE, S_DISCONN } state = S_IDLE; static char szBuf[1024]; static uint16_t idxBuf = 0; static WiFiClient client; static uint32_t timeStart; switch (state) { case S_IDLE: // initialise PRINTS("\nS_IDLE"); idxBuf = 0; state = S_WAIT_CONN; break; case S_WAIT_CONN: // waiting for connection { client = server.available(); if (!client) break; if (!client.connected()) break; #if DEBUG char szTxt[20]; sprintf(szTxt, "%03d:%03d:%03d:%03d", client.remoteIP()[0], client.remoteIP()[1], client.remoteIP()[2], client.remoteIP()[3]); PRINT("\nNew client @ ", szTxt); #endif timeStart = millis(); state = S_READ; } break; case S_READ: // get the first line of data PRINTS("\nS_READ "); while (client.available()) { char c = client.read(); if ((c == '\r') || (c == '\n')) { szBuf[idxBuf] = '\0'; client.flush(); PRINT("\nRecv: ", szBuf); state = S_EXTRACT; } else szBuf[idxBuf++] = (char)c; } if (millis() - timeStart > 1000) { PRINTS("\nWait timeout"); state = S_DISCONN; } break; case S_EXTRACT: // extract data PRINTS("\nS_EXTRACT"); // Extract the string from the message if there is one getData(szBuf, BUF_SIZE); state = S_RESPONSE; break; case S_RESPONSE: // send the response to the client PRINTS("\nS_RESPONSE"); // Return the response to the client (web page) client.print(WebResponse); client.print(WebPage); state = S_DISCONN; break; case S_DISCONN: // disconnect client PRINTS("\nS_DISCONN"); client.flush(); client.stop(); state = S_IDLE; break; default: state = S_IDLE; } } void setup() { Serial.begin(57600); PRINTS("\n[MD_Parola WiFi Message Display]\nType a message for the scrolling display from your internet browser"); P.begin(); P.setIntensity(0); P.displayClear(); P.displaySuspend(false); P.displayScroll(curMessage, PA_LEFT, scrollEffect, frameDelay); curMessage[0] = newMessage[0] = '\0'; // Connect to and initialise WiFi network PRINT("\nConnecting to ", ssid); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { PRINT("\n", err2Str(WiFi.status())); delay(500); } PRINTS("\nWiFi connected"); // Start the server server.begin(); PRINTS("\nServer started"); // Set up first message as the IP address sprintf(curMessage, "%03d:%03d:%03d:%03d", WiFi.localIP()[0], WiFi.localIP()[1], WiFi.localIP()[2], WiFi.localIP()[3]); PRINT("\nAssigned IP ", curMessage); } void loop() { handleWiFi(); if (P.displayAnimate()) { if (newMessageAvailable) { strcpy(curMessage, newMessage); newMessageAvailable = false; } P.displayReset(); } } |