Mini-Multi-Tool Computer (MMTC v1.2) EASY DIY LCD NO SD and all run on one Arduino (SIMPLEST and MOST COMPACT)

1#include <LiquidCrystal.h>
2#include <math.h>
3
4// ─── LCD & BACKLIGHT ─────────────────────────────────────────
5const int rs = 2, en = 3, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
6LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
7
8const int cs = 9, bl = 10;
9const int CONTRAST = 1, BACKLIGHT = 50;
10
11// ─── BUTTONS & SCREENS ───────────────────────────────────────
12const int HS_PIN  = 0;    // H button
13const int MS_PIN  = 1;    // M button
14const int BTN_PIN = 8;    // page toggle
15const uint8_t MAX_SCREENS = 3;
16uint8_t currentScreen = 0;
17
18// ─── CLOCK VARIABLES ─────────────────────────────────────────
19int h = 9, m = 0, s = 8, flag = 1;
20uint32_t lastSec  = 0;
21uint32_t lastUpdate = 0;
22
23// ─── DEGREE CHAR ──────────────────────────────────────────────
24byte degreeChar[8] = {
25  B00110, B01001, B00110, B00000,
26  B00000, B00000, B00000, B00000
27};
28
29// ─── CALCULATOR (PAGE B) ─────────────────────────────────────
30const char calcMenu[] = {
31  '0','1','2','3','4','5','6','7','8','9',
32  '+','-','*','/','=','C'
33};
34const int CALC_MENU_LEN = sizeof(calcMenu);
35int calcIdx = 0;
36String calcExp;
37bool prevHs_Calc = HIGH, prevMs_Calc = HIGH;
38
39// ─── PERFORMANCE DASHBOARD (PAGE C) ──────────────────────────
40unsigned long lastPerfUpdate = 0;
41
42// ──────────────────────────────────────────────────────────────
43void setup() {
44  pinMode(HS_PIN,  INPUT_PULLUP);
45  pinMode(MS_PIN,  INPUT_PULLUP);
46  pinMode(BTN_PIN, INPUT_PULLUP);
47
48  analogWrite(cs, CONTRAST);
49  analogWrite(bl, BACKLIGHT);
50
51  lcd.begin(16,2);
52  lcd.noBlink();
53  lcd.noCursor();
54  lcd.createChar(0, degreeChar);
55
56  drawPageA();
57}
58
59void loop() {
60  uint32_t now = millis();
61
62  // ─── clock tick ───────────────────────────────────────
63  if (now - lastSec >= 1000) {
64    lastSec += 1000;
65    tickClock();
66    if (currentScreen == 0) redrawTime();
67  }
68
69  // ─── page toggle ──────────────────────────────────────
70  if (digitalRead(BTN_PIN) == LOW) {
71    currentScreen = (currentScreen + 1) % MAX_SCREENS;
72    delay(300);
73    lcd.clear();
74    prevHs_Calc = prevMs_Calc = HIGH;
75
76    if (currentScreen == 0) drawPageA();
77    else if (currentScreen == 1) drawPageB();
78    else drawPageC();
79  }
80
81  // ─── PAGE A: clock + temp ─────────────────────────────
82  if (currentScreen == 0) {
83    if (digitalRead(HS_PIN) == LOW) setHour();
84    if (digitalRead(MS_PIN) == LOW) setMin();
85
86    if (now - lastUpdate >= 1000) {
87      lastUpdate = now; 
88      drawTemp();
89    }
90  }
91
92  // ─── PAGE B: calculator ───────────────────────────────
93  else if (currentScreen == 1) {
94    bool hsNow = digitalRead(HS_PIN);
95    if (prevHs_Calc == HIGH && hsNow == LOW) {
96      calcIdx = (calcIdx + 1) % CALC_MENU_LEN;
97      lcd.setCursor(2,1);
98      lcd.print(calcMenu[calcIdx]);
99      delay(200);
100    }
101    prevHs_Calc = hsNow;
102
103    bool msNow = digitalRead(MS_PIN);
104    if (prevMs_Calc == HIGH && msNow == LOW) {
105      handleCalcSelect(calcMenu[calcIdx]);
106      delay(200);
107    }
108    prevMs_Calc = msNow;
109  }
110
111  // ─── PAGE C: performance dashboard ────────────────────
112  else {
113    if (now - lastPerfUpdate >= 1000) {
114      lastPerfUpdate = now;
115      drawPageC();
116    }
117  }
118}
119
120// ─── DRAW STATIC PAGES ─────────────────────────────────
121void drawPageA() {
122  lcd.setCursor(0,0); lcd.print("Time 00:00:00 AM");
123  lcd.setCursor(0,1); lcd.print("Temp:      "); lcd.write((byte)8); lcd.print("F");
124  lastSec = millis();
125  lastUpdate = millis();
126  redrawTime();
127  drawTemp();
128}
129
130void drawPageB() {
131  calcExp = "";
132  calcIdx = 0;
133  lcd.setCursor(0,0); lcd.print("Calc:");
134  lcd.setCursor(0,1); lcd.print("> ");
135  lcd.setCursor(2,1); lcd.print(calcMenu[calcIdx]);
136}
137
138void drawPageC() {
139  lcd.clear();
140
141  // Free RAM display
142  int ram = freeRam();
143  float ramKB = ram / 1024.0;
144  lcd.setCursor(0,0);
145  lcd.print("Free RAM:");
146  lcd.setCursor(10,0);
147  lcd.print(ramKB, 1); lcd.print("KB");
148
149  // Simulated CPU load (Technically The Arduino UNO R3's CPU can't multitask so it is always running)
150  int load = ((analogRead(A0) + analogRead(9) + analogRead(10) + analogRead(4) + analogRead(5) + analogRead(6) + analogRead(7) + (2048 - ram)) / 2.25);
151  int percent = map(load, 0, 1023, 0, 100);
152  lcd.setCursor(0,1);
153  lcd.print("CPU Load:");
154  lcd.print(percent); lcd.print("%   ");
155}
156
157// ─── REDRAW HELPERS ────────────────────────────────────
158void redrawTime() {
159  char b[3];
160  sprintf(b,"%02d", h); lcd.setCursor(5,0); lcd.print(b);
161  sprintf(b,"%02d", m); lcd.setCursor(8,0); lcd.print(b);
162  sprintf(b,"%02d", s); lcd.setCursor(11,0); lcd.print(b);
163  lcd.setCursor(14,0); lcd.print(flag ? "PM" : "AM");
164}
165
166// ─── DRAW TEMP (UPDATED TO AVERAGE MULTIPLE READINGS) ─────────────────────────────────
167void drawTemp() {
168  // Take 10 quick readings and average them
169  long sum = 0;
170  for (int i = 0; i < 10; i++) {
171    sum += analogRead(A0);
172    delay(5);
173  }
174  int avgReading = sum / 10;
175
176  // Convert average reading to Fahrenheit
177  int t = (int)(avgReading * 0.48828125);
178  char b[3];
179  sprintf(b, "%2d", t);
180  lcd.setCursor(7,1);
181  lcd.print(b);
182}
183
184// ─── CLOCK HELPERS ─────────────────────────────────────
185void tickClock() {
186  s++; if (s>=60){ s=0; m++; }
187  if (m>=60){ m=0; h++; }
188  if (h>=13){ h=1; flag^=1; }
189}
190
191void setHour() {
192  h++; if (h>=13){ h=1; flag^=1; }
193  redrawTime();
194  delay(200);
195}
196
197void setMin() {
198  s = 0; m++;
199  if (m>=60){ m=0; h++; }
200  if (h>=13){ h=1; flag^=1; }
201  redrawTime();
202  delay(200);
203}
204
205// ─── CALCULATOR HELPERS ────────────────────────────────
206void handleCalcSelect(char c) {
207  if (c == 'C') {
208    calcExp = "";
209    lcd.setCursor(2,1);
210    lcd.print("                "); // Clear line
211    lcd.setCursor(2,1);
212  }
213  else if (c == '=') {
214    double val = evalExp(calcExp);
215    calcExp = String(val, 4);
216    // Trim trailing zeros
217    while(calcExp.endsWith("0")) calcExp.remove(calcExp.length() - 1);
218    if(calcExp.endsWith(".")) calcExp.remove(calcExp.length() - 1);
219
220    lcd.setCursor(6,0);
221    lcd.print("                ");
222    lcd.setCursor(6,0);
223    lcd.print(calcExp);
224  }
225  else {
226    calcExp += c;
227    lcd.setCursor(6,0);
228    lcd.print(calcExp);
229  }
230}
231
232// Basic expression evaluator for +, -, *, / with no parentheses or operator precedence
233double evalExp(String expr) {
234  double result = 0;
235  char op = '+';
236  String number = "";
237
238  for (unsigned int i = 0; i < expr.length(); i++) {
239    char c = expr.charAt(i);
240    if ((c >= '0' && c <= '9') || c == '.') {
241      number += c;
242    } else if (c == '+' || c == '-' || c == '*' || c == '/') {
243      double numVal = number.toFloat();
244      if (op == '+') result += numVal;
245      else if (op == '-') result -= numVal;
246      else if (op == '*') result *= numVal;
247      else if (op == '/') {
248        if (numVal != 0) result /= numVal;
249        else return 0;
250      }
251      op = c;
252      number = "";
253    }
254  }
255  // Last number
256  double numVal = number.toFloat();
257  if (op == '+') result += numVal;
258  else if (op == '-') result -= numVal;
259  else if (op == '*') result *= numVal;
260  else if (op == '/') {
261    if (numVal != 0) result /= numVal;
262    else return 0;
263  }
264
265  return result;
266}
267
268// ─── MEMORY HELPER ─────────────────────────────────────
269#ifdef __arm__
270int freeRam() {
271  char top;
272  return &top - reinterpret_cast<char*>(sbrk(0));
273}
274#else
275extern unsigned int __heap_start;
276extern void *__brkval;
277int freeRam() {
278  int v;
279  return (int)&v - (__brkval == 0 ? (int)&__heap_start : (int)__brkval);
280}
281#endif