Legacy RS232 to WIFI adapter / Air Quality Cell Phone App

prusaprinters

<p>I've been playing with computers since the 1970's. I've gone thru many generations of computers and sensors. Technology is always changing and it obsoletes your old projects. I have several old sensors that have RS232 interfaces. They still work fine (although in many cases the computers died or the service I was pushing the data to went out of business).</p><p>This project show how simple it is to make an RS232 to WIFI adapter that pushes data to the Internet. It then shows you how to make a cell phone app to display the data.</p><p>The project parts:</p><ul><li>Dylos Air Quality Monitor ( <a href="https://amzn.to/2V8Uy0W">https://amzn.to/2V8Uy0W</a> )</li><li>RS232 to TTL Converter ( <a href="https://amzn.to/376AdyM">https://amzn.to/376AdyM</a> )</li><li>5V Micro USB Power Adapter ( <a href="https://amzn.to/3pZ3MLn">https://amzn.to/3pZ3MLn</a> )</li><li>Particle Photon ( <a href="https://www.sparkfun.com/products/13774">https://www.sparkfun.com/products/13774</a> )</li><li>DB9 Null Modem ( <a href="https://amzn.to/3fF0yIf">https://amzn.to/3fF0yIf</a> )</li><li>Jumper wires ( <a href="https://amzn.to/37e4trs">https://amzn.to/37e4trs</a> )</li><li>PETG Transparent filament ( <a href="https://shop.prusa3d.com/en/prusament/1216-prusament-petg-clear-1kg.html">https://shop.prusa3d.com/en/prusament/1216-prusament-petg-clear-1kg.html</a> )</li></ul><p>As an Amazon Associate I earn from qualifying purchases.</p><figure class="media"><oembed url="https://youtu.be/Vn33wZlQlN4"></oembed></figure><p>Particle code:</p><p>/* &nbsp; Program by Christopher Nafis &nbsp; Written November 2020 &nbsp; Reads data from the Dylos DC1100 with PC Interface &nbsp; Send the data to a Blynk application or to IFTTT &nbsp; The DC1100 is a true Laser Particle Counter with 2 size ranges - small (&gt;1 micron bacteria, mold, etc) large (&gt;5 micron pollen, etc.) */ #include #define BLYNK_PRINT Serial &nbsp;// Set serial output for debug prints #include "Particle.h" const size_t READ_BUF_SIZE = 64; char auth[] = "YourBlynkKey"; BlynkTimer timer; WidgetLCD lcd(V2); // Forward declarations void processBuffer(); // Global variables char readBuf[READ_BUF_SIZE]; size_t readBufOffset = 0; int small = 0; int large = 0; void setup() { &nbsp; &nbsp;Serial.begin(9600); &nbsp; &nbsp;Serial1.begin(9600); &nbsp; &nbsp;delay(5000); // Allow board to settle &nbsp; &nbsp;Particle.variable("small", small); &nbsp; &nbsp;Particle.variable("large", large); &nbsp; &nbsp;Blynk.begin(auth); } void loop() { &nbsp; &nbsp;// Read data from serial &nbsp; &nbsp;while(Serial1.available()) { &nbsp; &nbsp; &nbsp; &nbsp;if (readBufOffset &lt; READ_BUF_SIZE) { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;char c = Serial1.read(); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;if (c != '\n') { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;// Add character to buffer &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;readBuf[readBufOffset++] = c; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;else { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;// End of line character found, process line &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;readBuf[readBufOffset] = 0; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;processBuffer(); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;readBufOffset = 0; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp; &nbsp; &nbsp;else { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Serial.println("readBuf overflow, emptying buffer"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;readBufOffset = 0; &nbsp; &nbsp; &nbsp; &nbsp;} &nbsp; &nbsp;} &nbsp; &nbsp;Blynk.run(); } // Since the Dylos only outputs values once a minute, it is OK to // put the Blynk updates in the loop without a separate timer void processBuffer() { &nbsp; &nbsp;sscanf(readBuf,"%d,%d",&amp;small,&amp;large); &nbsp;// units are average particles/100 per cubic foot &nbsp; &nbsp;Serial.print(small); &nbsp; &nbsp;Serial.print(' '); &nbsp; &nbsp;Serial.println(large); &nbsp; &nbsp;Blynk.virtualWrite(V0, small*100); &nbsp; &nbsp;Blynk.virtualWrite(V1, large*100); &nbsp; &nbsp;// The Dylos has a "rule of thumb" charts on the back of the sensor &nbsp; &nbsp;lcd.clear(); &nbsp; &nbsp;lcd.print(1,0,"Air Quality is:"); &nbsp; &nbsp;if (small &lt; 75) &nbsp; &nbsp; &nbsp; lcd.print(1,1,"Excellent"); &nbsp; &nbsp; &nbsp; else if (small &lt; 150) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;lcd.print(1,1,"Very Good"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;else if (small &lt; 300) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; lcd.print(1,1,"Good"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else if (small &lt; 1050) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;lcd.print(1,1,"Fair"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;else if (small &lt; 3000) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; lcd.print(1,1,"Poor"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;lcd.print(1,1,"Very Poor"); }</p>