From 116a48d410cbb12ff43d2d9f96b4b899d706086d Mon Sep 17 00:00:00 2001
From: Eric <luv.ilho@gmail.com>
Date: Sat, 27 Jul 2019 12:55:38 -0700
Subject: [PATCH] ESP32 | Flutter | BLE - Ultrasonic Range Finder with 1.5inch
 OLED, Part 1

---
 .../Esp32_Ultrasonic_module.ino               | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 Esp32_ultrasonic_range_finder/Esp32_Ultrasonic_module/Esp32_Ultrasonic_module.ino

diff --git a/Esp32_ultrasonic_range_finder/Esp32_Ultrasonic_module/Esp32_Ultrasonic_module.ino b/Esp32_ultrasonic_range_finder/Esp32_Ultrasonic_module/Esp32_Ultrasonic_module.ino
new file mode 100644
index 0000000..6e9b871
--- /dev/null
+++ b/Esp32_ultrasonic_range_finder/Esp32_Ultrasonic_module/Esp32_Ultrasonic_module.ino
@@ -0,0 +1,93 @@
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1351.h>
+
+#define SCREEN_WIDTH 128
+#define SCREEN_HEIGHT 128
+
+#define SCLK_PIN 18
+#define MOSI_PIN 23
+#define DC_PIN   17
+#define CS_PIN   5
+#define RST_PIN  4
+#define TRIG_PIN 0
+#define ECHO_PIN 2
+
+#define BLACK           0x0000
+#define BLUE            0x001F
+#define RED             0xF800
+#define GREEN           0x07E0
+#define CYAN            0x07FF
+#define MAGENTA         0xF81F
+#define YELLOW          0xFFE0  
+#define WHITE           0xFFFF
+
+Adafruit_SSD1351 tft = Adafruit_SSD1351(SCREEN_WIDTH, SCREEN_HEIGHT, CS_PIN, DC_PIN, MOSI_PIN, SCLK_PIN, RST_PIN);
+long prev_distance;
+
+void setup() {
+  Serial.begin(115200);
+
+  pinMode(TRIG_PIN, OUTPUT);
+  pinMode(ECHO_PIN, INPUT);
+
+  initDrawing();
+
+}
+
+void initDrawing(){
+  tft.begin();
+  tft.fillRect(0, 0, 128, 128, WHITE);
+  tft.setRotation(2);
+  tft.setCursor(4, 0);
+  tft.setTextColor(BLUE);
+  tft.setTextSize(1);
+  tft.print("BT::Not connected!");
+
+  tft.setCursor(54, 100);
+  tft.setTextColor(MAGENTA);
+  tft.setTextSize(2);
+  tft.print("CM");
+}
+
+void loop() {
+  long duration, distance;
+  digitalWrite(TRIG_PIN, LOW);
+  delayMicroseconds(2);
+
+  digitalWrite(TRIG_PIN, HIGH);
+  delayMicroseconds(10);
+  digitalWrite(TRIG_PIN, LOW);
+
+  duration = pulseIn(ECHO_PIN, HIGH);
+  distance = microsecondsTocentimeters(duration);
+  Serial.print("Ultrasonic Distance : " );
+  Serial.print(distance);
+  Serial.println(" CM");
+  updateDistance(distance);
+  delay(30);
+}
+
+void updateDistance(long distance){
+  if(prev_distance != distance){
+    tft.fillRect(0, 30, 128, 70, WHITE);
+    tft.setCursor(34, 40);
+
+    if((int)distance < 10){
+      tft.setTextColor(RED);
+    }else if((int)distance > 10 && (int)distance <=99){
+      tft.setTextColor(BLACK);
+    }else if((int)distance > 100){
+      tft.setTextColor(GREEN);
+    }
+
+    tft.setTextSize(4);
+    String tempString = "";
+    tempString += (int)distance;
+    tft.print(tempString);
+    prev_distance = distance;
+  }
+}
+
+long microsecondsTocentimeters(long duration){
+  return duration /29 / 2;
+}