1 /*
   2   LabPSU2R, control of 2 switching PSU modules, with remote control
   3   Protocol: SCPI 1997.0
   4   2015-03-10 Rudolf Reuter DL5FA
   5   2016-10-17 RR, OUTPUT->STATe
   6 
   7   This program is free software; you can redistribute it and/or
   8   modify it under the terms of the GNU Lesser General Public
   9   License as published by the Free Software Foundation; either
  10   version 2.1 of the License, or (at your option) any later version.
  11 
  12   This program is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15   Lesser General Public License for more details.
  16 
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with this library; if not, write to the Free Software
  19   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20 
  21   version for LCD shield by ElecFreaks.com
  22   using internal Rotary Encoder (D2, D3) and Joystick (A0)
  23 
  24   Todo:  Display Power [W]
  25        Display Charge Capacity [mAh]
  26 
  27   Arduino LED: D13
  28 
  29   Encoder:  D2, D3, push contact A0 = show encoder value & intRemote = 0
  30 
  31   Joystick: A7 in  Analog Voltage Input from Joystick
  32               switch "left"   = show current limit value I1
  33               switch "right"  = show current limit value I2
  34               switch "up"     = No function
  35               switch "down"   = No function
  36               switch "Center Push"   = Move active set pointer
  37               switch "Encoder Push"  = show Encoder value
  38 
  39   LCD:  D4  LCD, D4
  40       D5  LCD, D5
  41       D6  LCD, D6
  42       D7  LCD, D7
  43       D8  LCD, RS
  44       D9  LCD, E
  45       D10 LCD, Illumination
  46 
  47   PSU:  D11 CL1 (CL = Current Limit)
  48       D12 CL2
  49       A0  Enable PSU
  50       A1  I1
  51       A2  U1
  52       A3  I2
  53       A4  SDA, I2C digital poti
  54       A5  SCL, I2C digital poti
  55       A6  U2
  56 
  57   Current limit function for encoder: f(x) = 0.0219 + 0.033 A
  58     Correction: 0.0213
  59   Voltage conversion: encoder = (U[V] - 32.7) * -0.126
  60   File: Schaltregler_Current_Limit.ods
  61 
  62   Library SerialCommand, version 3.6 (Stafan Rado)
  63   https://github.com/kroimon/Arduino-SerialCommand
  64   Patch for SerialCommand.h:
  65   l67 char delim[3]; // null-terminated list of character to be used as delimiters for tokenizing (default " ")
  66     2015-03-04 RR, 2 -> 3
  67   Patch for SerialCommand.cpp:
  68   l36 strcpy(delim, " :"); // strtok_r needs a null-terminated string
  69     2015-03-04 RR, " " -> " :" for SCPI
  70 
  71   Library for Digital Encoder and LCD
  72   http://www.elecfreaks.com/store/download/product/shield/LCD_Key_Shield/CODE/LCD_ENCKEY_TEST.zip
  73 
  74   Library for Digital Potentiometer MCP4461
  75   https://github.com/jmgiacalone/Arduino-libraries/tree/master/MCP4461
  76 
  77   The libraries must be copied to folder Arduino/libraries/
  78   MCP4461/
  79   Rotary/
  80   SerialCommand/
  81   --------------------------------*/
  82 
  83 //--------- Declarations
  84 #include <Rotary.h>
  85 #include <LiquidCrystal.h>
  86 #include <Wire.h>
  87 #include <MCP4461.h>
  88 
  89 #include <SerialCommand.h>
  90 
  91 #define arduinoLED 13 // Arduino LED on board
  92 
  93 SerialCommand sCmd; // The SerialCommand object
  94 
  95 //---------------------
  96 // Joystick defines
  97 #define btnNone 0
  98 #define btnUp 1
  99 #define btnRight 2
 100 #define btnDown 3
 101 #define btnCenter 4
 102 #define btnLeft 5
 103 #define btnEnc 6
 104 
 105 //set PSU pins
 106 #define ENA A0  // Enable PSU module
 107 #define CL1 11 // Current Limit 1, high=active
 108 #define CL2 12 // Current Limit 2, high=active
 109 #define I1 1   // analog Current PSU1
 110 #define U1 2   // analog Voltage PSU2
 111 #define I2 3   // analog Current PSU2
 112 #define U2 6   // analog Voltage PSU2 
 113 #define VOLT 0
 114 #define AMPERE 1
 115 #define DP_U1 0 // digital poti U1, Set
 116 #define DP_U2 1 // digital poti U2, Set
 117 #define DP_I1 2 // digital poti I1, Current Limit
 118 #define DP_I2 3 // digital poti I2, Current Limit
 119 // target ADC: 1023 = 25 V
 120 #define U_CONV1 39.3  // analog to Voltage factor 1 
 121 #define U_CONV2 39.7  // analog to Voltage factor 2 
 122 // target ADC: 1023 = 5 A
 123 #define I_CONV1 218.9  // analog to Ampere factor 1
 124 #define I_CONV2 218.9  // analog to Ampere factor 2
 125 #define CL_CONV 0.0213 // encoder to Current Limit Set
 126 #define CL_OFST 0.033  // Current Limit Offset
 127 #define UR_CONV1 -0.1023  // voltage to encoder factor 1
 128 #define UR_OFST1 26.73    // voltage to encoder Offset 1
 129 #define UR_CONV2 -0.1035  // voltage to encoder factor 2
 130 #define UR_OFST2 26.9    // voltage to encoder Offset 2
 131 #define Imin 0.04
 132 #define Imax 3.0
 133 #define Umin 0.5
 134 #define Umax 23.0
 135 
 136 // I2C/TWI for digital potentiometer MCP4461
 137 
 138 // http://www.elecfreaks.com/store/lcd-key-shield-p-688.html
 139 // http://www.komputer.de/zen/index.php?main_page=product_info&products_id=290
 140 Rotary r = Rotary(2, 3); // sets the pins the rotary encoder uses.
 141 LiquidCrystal lcd(8, 9, 4, 5, 6, 7);    // settings for EleyFreaks Key Shield
 142 
 143 int intEncoder;  // store Encoder movement
 144 int intEncoder_old;
 145 float fDisp[4];  // float value for LCD Diplay
 146 float fVoltDisp[2]; /// Volt for Display
 147 int intVoltM[2];   // Volt measured
 148 int intSet[4] = {255, 255, 9, 9};   // Volt set, about 0.5 V, 230 mA
 149 float fAmpereDisp[2];
 150 float fUR_CONV[2] = {UR_CONV1, UR_CONV2};
 151 float fUR_OFST[2] = {UR_OFST1, UR_OFST2};
 152 int intAmpereM[2];
 153 int result;
 154 int intValue;  // analog value
 155 int intActive = DP_U1; // active value
 156 int intJoystick;
 157 int intPressed;
 158 unsigned long time;
 159 long previousMs400 = 0;
 160 long interval400 = 400;
 161 long previousMs200 = 0;
 162 long interval200 = 200;
 163 int adc_key_in = 0;
 164 char charCH1;
 165 char charCH2;
 166 String strMessage = String(20);
 167 char charMessage[20];
 168 int intNumChar;
 169 int intNumCharRcv;
 170 int intOut = 1;  // Output
 171 int intSel = 0;  // PSU number 0 | 1
 172 int intRemote;
 173 
 174 // Instantiate objects used in this project
 175 MCP4461 myMCP4461;
 176 
 177 //----- Setup ------------------------
 178 void setup() {
 179   Serial.begin(9600);
 180   Serial.println("LabPSU2R V1.1");
 181   pinMode(ENA, OUTPUT);
 182   pinMode(A1, INPUT);
 183   pinMode(A2, INPUT);
 184   pinMode(A3, INPUT);
 185   pinMode(A6, INPUT);
 186   pinMode(A7, INPUT);
 187   pinMode(CL1, INPUT_PULLUP); // Diode
 188   pinMode(CL2, INPUT_PULLUP); // Diode
 189 
 190   // set Backlight ON
 191   pinMode(10, OUTPUT);
 192   digitalWrite(10, 1);
 193 
 194   lcd.begin (16, 2); // display init
 195   lcd.setCursor(0, 0); // Char 1, Line 1
 196   lcd.print(" LabPSU2R  ");
 197   lcd.setCursor(0, 1); // Char 1, Line 2
 198   lcd.print("DL5FA 2016-10-07");
 199   delay(3000);
 200   lcd.clear();
 201 
 202   Wire.begin();
 203   Serial.println("Wire.begin");
 204   TWBR = 12; // 400 kHz (maximum)
 205   myMCP4461.begin();
 206   Serial.println("myMCP4461.begin");
 207   result = myMCP4461.testConnection();
 208   Serial.print("I2Cinit: ");
 209   Serial.print(result);
 210   if (result == 1) Serial.println(" OK");
 211   else Serial.println(" Error");
 212   result = myMCP4461.setVolatileWiper(DP_U1, intSet[DP_U1]); // U1 min.
 213   Serial.print("DP0-U1, result:");
 214   if (result == 1) Serial.print(" OK");
 215   else Serial.print(" Error");
 216   Serial.print(", set: ");
 217   Serial.println(intSet[DP_U1]);
 218   result = myMCP4461.getVolatileWiper(DP_U1); // U1 min.
 219   Serial.print("DP0-U1, get: ");
 220   Serial.print(result);
 221   if (result == intSet[DP_U1]) Serial.println(" OK");
 222   else Serial.println(" Error");
 223 
 224   result = myMCP4461.setVolatileWiper(DP_U2, intSet[DP_U2]); // U2 min.
 225   result = myMCP4461.setVolatileWiper(DP_I1, intSet[DP_I1]);   // Curren Limit I1
 226   result = myMCP4461.setVolatileWiper(DP_I2, intSet[DP_I2]);   // Curren Limit I2
 227 
 228   analogReference(DEFAULT); // Reference voltage is +5 V
 229 
 230   // digital Encoder interrupt
 231   PCICR |= (1 << PCIE2);
 232   PCMSK2 |= (1 << PCINT18) | (1 << PCINT19);
 233   sei();
 234 
 235   digitalWrite(ENA, 1); // Enable PSU Modules
 236 
 237   pinMode(arduinoLED, OUTPUT); // Configure the onboard LED for output
 238   digitalWrite(arduinoLED, LOW); // default to LED off
 239 
 240   // Setup callbacks for SerialCommand commands
 241   sCmd.addCommand("ON", LED_on); // Turns LED on
 242   sCmd.addCommand("OFF", LED_off); // Turns LED off
 243   sCmd.addCommand("HELLO", sayHello); // Echos the string argument back
 244   sCmd.addCommand("P", processCommand); // Converts two arguments to integers and echos them back
 245   sCmd.addCommand("*IDN?", Ident);  // Send Identification string
 246   sCmd.addCommand("INST", Instrument);  // SCPI Instrument
 247   sCmd.addCommand("MEAS", Measure); // SCPI Measure
 248   sCmd.addCommand("OUTP", Output);  // SCPI Output
 249   sCmd.addCommand("SOUR", Source);  // SCPI Source
 250   sCmd.addCommand("*STB?", Status); // Query Status Byte
 251   sCmd.addCommand("SYST", System); // SCPI System
 252   sCmd.setDefaultHandler(unrecognized); // Handler for command that isn't matched (says "What?")
 253   Serial.println("sCmd Ready");
 254 }
 255 
 256 //----- main -------------------------
 257 void loop() {
 258   // update LCD every 400 ms
 259   unsigned long currentMillis = millis();
 260 
 261   //---------- refresh LCD every 400 ms
 262   if (currentMillis - previousMs400 > interval400) {
 263     previousMs400 = currentMillis;
 264     lcd.setCursor(0, 0); // Char 1, Line 1
 265     if ((intActive == DP_U1) && (intJoystick == btnEnc))
 266       show_EncValue(intSet[intActive]);
 267     else {
 268       intValue = analogRead(U1);
 269       fDisp[DP_U1] = intValue / U_CONV1;
 270       if (fDisp[DP_U1] < 10.0)
 271         lcd.print("0");
 272       lcd.print(fDisp[DP_U1], 1);
 273     }
 274     lcd.print("V1");
 275     charCH1 = ' ';
 276     if (intActive == DP_U1)   charCH1 = '*';
 277     if (digitalRead(CL1) > 0) charCH1 = 'L';
 278     lcd.print(charCH1);
 279     lcd.print(' ');
 280     if ((intActive == DP_U2) && (intJoystick == btnEnc))
 281       show_EncValue(intSet[intActive]);
 282     else {
 283       intValue = analogRead(U2);
 284       fDisp[DP_U2] = intValue / U_CONV2;
 285       if (fDisp[DP_U2] < 10.0)
 286         lcd.print("0");
 287       lcd.print(fDisp[DP_U2], 1);
 288     }
 289     lcd.print("V2");
 290     charCH2 = ' ';
 291     if (intActive == DP_U2)   charCH2 = '*';
 292     if (digitalRead(CL2) > 0) charCH2 = 'L';
 293     lcd.print(charCH2);
 294     if (intRemote > 0) lcd.print('R');
 295     else lcd.print(' ');
 296     lcd.setCursor(0, 1); // Char 1, Line 2
 297     if ( intJoystick == btnLeft) show_CurLimit(intSet[DP_I1]);
 298     else {
 299       if ((intActive == DP_I1) && (intJoystick == btnEnc))
 300         show_EncValue(intSet[intActive]);
 301       else {
 302         intValue = analogRead(I1);
 303         fDisp[DP_I1] = intValue / I_CONV1;
 304         lcd.print(fDisp[DP_I1], 2);
 305       }
 306     }
 307     lcd.print("A1");
 308     if (intActive == DP_I1) {
 309       lcd.print('*');
 310     } else lcd.print(' ');
 311     lcd.print(' ');
 312     if (intJoystick == btnRight) show_CurLimit(intSet[DP_I2]);
 313     else {
 314       if ((intActive == DP_I2) && (intJoystick == btnEnc))
 315         show_EncValue(intSet[intActive]);
 316       else {
 317         intValue = analogRead(I2);
 318         fDisp[DP_I2] = intValue / I_CONV2;
 319         lcd.print(fDisp[DP_I2], 2);
 320       }
 321     }
 322     lcd.print("A2");
 323     if (intActive == DP_I2) {
 324       lcd.print('*');
 325     } else lcd.print(' ');
 326     if (intJoystick == btnEnc) intRemote = 0; // Manual to Local mode
 327   }
 328 
 329   //------ readout joystick every 200 ms
 330   if (currentMillis - previousMs200 > interval200) {
 331     previousMs200 = currentMillis;
 332     intJoystick = read_Joystick();
 333     if (intJoystick > btnNone) intPressed = intJoystick;
 334     if ((intPressed > btnNone) && (intJoystick == btnNone)) {
 335       // button just released
 336       switch (intPressed) {
 337         case btnUp:
 338           break;
 339         case btnRight:
 340           break;
 341         case btnDown:
 342           break;
 343         case btnCenter:
 344           intActive += 1;
 345           if (intActive > DP_U2) intActive = DP_U1;
 346           break;
 347         case btnLeft:
 348           break;
 349       }
 350       intPressed = btnNone;  // reset button
 351     }
 352   }
 353 
 354   // process Encoder for Set values (Voltage, Current) via Interrupt
 355   int intActive2; // consider Ampere setting switch
 356   if (intEncoder != intEncoder_old)  {
 357     intEncoder_old = intEncoder;
 358     if (intRemote == 0) {
 359       intActive2 = intActive;
 360       if (intJoystick == btnLeft)  intActive2 = DP_I1;
 361       if (intJoystick == btnRight) intActive2 = DP_I2;
 362       intValue = intSet[intActive2];
 363       if (intActive2 < 2)
 364         intValue = intValue - intEncoder_old;  // Set Voltage
 365       else
 366         intValue = intValue + intEncoder_old; // Set Ampere
 367       if (intValue > 255) intValue = 255;
 368       if (intValue < 1) intValue = 1;
 369       intSet[intActive2] = intValue;
 370       result = myMCP4461.setVolatileWiper(intActive2, intValue); // set poti
 371     }
 372     intEncoder = 0;
 373     // for debug
 374     //Serial.print("Encoder, Active, Value : ");
 375     //Serial.print(intEncoder_old);
 376     //Serial.print(", ");
 377     //Serial.print(intActive2);
 378     //Serial.print(", ");
 379     //Serial.println(intValue);
 380     intEncoder_old = 0;
 381   }
 382 
 383   sCmd.readSerial(); // We don't do much, just process serial commands
 384 
 385 }
 386 //-------- Subroutines -------------
 387 void LED_on() {
 388   Serial.println("LED on");
 389   digitalWrite(arduinoLED, HIGH);
 390 }
 391 void LED_off() {
 392   Serial.println("LED off");
 393   digitalWrite(arduinoLED, LOW);
 394 }
 395 void sayHello() {
 396   char *arg;
 397   arg = sCmd.next(); // Get the next argument from the SerialCommand object buffer
 398   if (arg != NULL) { // As long as it existed, take it
 399     Serial.print("Hello ");
 400     Serial.println(arg);
 401   }
 402   else {
 403     Serial.println("Hello, whoever you are");
 404   }
 405 }
 406 void processCommand() {
 407   int aNumber;
 408   char *arg;
 409   Serial.println("We're in processCommand");
 410   arg = sCmd.next();
 411   if (arg != NULL) {
 412     aNumber = atoi(arg); // Converts a char string to an integer
 413     Serial.print("First argument was: ");
 414     Serial.println(aNumber);
 415   }
 416   else {
 417     Serial.println("No arguments");
 418   }
 419   arg = sCmd.next();
 420   if (arg != NULL) {
 421     aNumber = atol(arg);
 422     Serial.print("Second argument was: ");
 423     Serial.println(aNumber);
 424   }
 425   else {
 426     Serial.println("No second argument");
 427   }
 428 }
 429 void Ident() {
 430   Serial.println("LabPSU2_2015-04-04_DL5FA");
 431 }
 432 
 433 void System () {  // Version date of SCPI & Remote
 434   char *arg;
 435   arg = sCmd.next();
 436   strMessage = arg;  // needed for "substring()"
 437   if (arg != NULL) { // As long as it existed, take it
 438     if (strMessage.substring(0, 4) == "VERS") Serial.println("1997.0");
 439     if (strMessage.substring(0, 3) == "REM") intRemote = 1;
 440     if (strMessage.substring(0, 3) == "LOC") intRemote = 0;
 441   }
 442 }
 443 
 444 void Source () {  // Current or Voltage
 445   char *arg;
 446   float fValue;
 447   int intLen;
 448   float fCurLimit;
 449   arg = sCmd.next();
 450   if (arg != NULL) {
 451     strMessage = arg;  // needed for "substring()"
 452     if (strMessage.substring(0, 4) == "VOLT") {
 453       intLen = strMessage.length();
 454       if (strMessage.charAt(intLen - 1) == '?') { // Query voltage
 455         arg = sCmd.next();
 456         if (arg != NULL) {
 457           strMessage = arg;
 458           if (strMessage.substring(0, 3) == "MIN") Serial.println(Umin);
 459           if (strMessage.substring(0, 3) == "MAX") Serial.println(Umax);
 460         } else {
 461           fValue = (intSet[DP_U1 + intSel] * fUR_CONV[intSel] + fUR_OFST[intSel]) ;
 462           Serial.println(fValue);
 463         }
 464       }
 465       else {  // set voltage
 466         arg = sCmd.next();
 467         if (arg != NULL) {
 468           strMessage = arg;
 469           fValue = strMessage.toFloat();
 470           if ((fValue >= Umin) && (fValue <= Umax)) {  // check for valid
 471             intSet[DP_U1 + intSel] = (fValue - fUR_OFST[intSel]) / fUR_CONV[intSel];
 472             result = myMCP4461.setVolatileWiper(DP_U1 + intSel, intSet[DP_U1 + intSel]);
 473           }
 474         }
 475       }
 476     } else  // current
 477       if (strMessage.substring(0, 4) == "CURR") {
 478         intLen = strMessage.length();
 479         if (strMessage.charAt(intLen - 1) == '?') { // Query current
 480           arg = sCmd.next();
 481           if (arg != NULL) {
 482             strMessage = arg;
 483             if (strMessage.substring(0, 3) == "MIN") Serial.println(Imin);
 484             if (strMessage.substring(0, 3) == "MAX") Serial.println(Imax);
 485           } else {
 486             fCurLimit = intSet[intSel + 2] * CL_CONV + CL_OFST;
 487             Serial.println(fCurLimit);
 488             //Serial.print(' ');
 489             //Serial.println(intSet[intSel+2]);
 490           }
 491         }
 492         else {  // set current limit
 493           arg = sCmd.next();
 494           if (arg != NULL) {
 495             strMessage = arg;
 496             fValue = strMessage.toFloat();
 497             if ((fValue >= Imin) && (fValue <= Imax)) {  // check for valid
 498               intSet[DP_I1 + intSel] = (fValue - CL_OFST) / CL_CONV;
 499               result = myMCP4461.setVolatileWiper(DP_I1 + intSel, intSet[DP_I1 + intSel]);
 500             }
 501           }
 502         }
 503       }
 504   }
 505 }
 506 
 507 void Measure () {  // Current or Voltage
 508   char *arg;
 509   arg = sCmd.next();
 510   if (arg != NULL) {
 511     strMessage = arg;  // needed for "substring()"
 512     if (strMessage.substring(0, 4) == "VOLT") {
 513       Serial.println(fDisp[DP_U1 + intSel]);
 514     }
 515     if (strMessage.substring(0, 4) == "CURR") {
 516       Serial.println(fDisp[DP_I1 + intSel]);
 517     }
 518   }
 519 }
 520 
 521 void Instrument () {  // PSU 1 or 2
 522   char *arg;
 523   int intLen;
 524   int intParam;
 525   arg = sCmd.next();
 526   if (arg != NULL) {
 527     strMessage = arg;  // needed for "substring()"
 528     if (strMessage.substring(0, 4) == "NSEL") {
 529       intLen = strMessage.length();
 530       if (strMessage.charAt(intLen - 1) == '?') { // Query
 531         Serial.println(intSel + 1);
 532       } else {
 533         arg = sCmd.next();
 534         if (arg != NULL) {
 535           strMessage = arg;
 536           intParam = strMessage.toInt();
 537           if ((intParam >= 1) && (intParam <= 2)) {  // check for valid
 538             intSel = intParam - 1;
 539           }
 540         }
 541       }
 542     }
 543   }
 544 }
 545 
 546 void Status() {  // show Current Limit
 547   char cStatus = 0x30;
 548   if (digitalRead(CL1) > 0) cStatus += 0x01;
 549   if (digitalRead(CL2) > 0) cStatus += 0x02;
 550   if (intRemote > 0)        cStatus += 0x04;
 551   Serial.println(cStatus);
 552 }
 553 
 554 void Output () {  // PSU OFF | ON
 555   char *arg;
 556   int intLen;
 557   arg = sCmd.next();
 558   if (arg != NULL) {
 559     strMessage = arg;  // needed for "substring()"
 560     if (strMessage.substring(0, 4) == "STAT") {
 561       intLen = strMessage.length();
 562       if (strMessage.charAt(intLen - 1) == '?') { // Query
 563         if (intOut == 0) Serial.println("OFF");
 564         else Serial.println("ON");
 565       } else {
 566         arg = sCmd.next();
 567         if (arg != NULL) {
 568           strMessage = arg;
 569           if (strMessage.substring(0, 3) == "OFF") {
 570             //digitalWrite(arduinoLED, HIGH);
 571             //delay(500);
 572             //digitalWrite(arduinoLED, LOW);
 573             intOut = 0;
 574             digitalWrite(ENA, 0); // PSU Modules -> OFF
 575           } else {
 576             intOut = 1;
 577             digitalWrite(ENA, 1); // PSU Modules -> ON
 578           }
 579         }
 580       }
 581     }
 582   }
 583 }
 584 
 585 // This gets set as the default handler, and gets called when no other command matches.
 586 void unrecognized(const char *command) {
 587   Serial.println("What?");
 588 }
 589 
 590 //------- show encoder value (4 places) instead of analog value
 591 void show_EncValue(int intEncValue) {
 592   // intEncoder: 1..255
 593   if (intEncValue < 100)
 594     lcd.print("0");
 595   if (intEncValue < 10)
 596     lcd.print("0");
 597   lcd.print(intEncValue);
 598   lcd.print(' ');
 599 }
 600 
 601 //------ show current limit value in A, instead of analog value
 602 void show_CurLimit(int intCurLimit) {
 603   // intCurLimit: 1..255
 604   float fCurLimit;
 605   fCurLimit = intCurLimit * CL_CONV + CL_OFST;
 606   lcd.print(fCurLimit, 2);
 607 }
 608 
 609 //------ read the joystick
 610 int read_Joystick() {
 611   adc_key_in = analogRead(7); // read the value from the sensor
 612   // 4.95 V = 1023
 613   // Serial.println(adc_key_in);
 614 
 615   if (adc_key_in > 1000) return btnNone; // 1000 = 4,84 V
 616   if (adc_key_in < 50) return   btnLeft;   //   50 = 0.24 V (0.01 V)
 617   if (adc_key_in < 150) return  btnUp;    //  150 = 0,73 V (0.35 V)
 618   if (adc_key_in < 250) return  btnRight; //  250 = 1,21 V (1,05 V)
 619   if (adc_key_in < 450) return  btnCenter;//  450 = 2,18 V (2,00 V)
 620   if (adc_key_in < 700) return  btnDown;  //  700 = 3,39 V (3,18 V)
 621   if (adc_key_in < 903) return  btnEnc;   //  903 = 4,37 V (3,90 V)
 622   return btnNone; // when all others fail, return this...
 623 }
 624 
 625 //----- digital Encoder Interrupt Service Routine
 626 ISR(PCINT2_vect) {
 627   unsigned char result = r.process();
 628   if (result) {
 629     if (result == DIR_CW) {
 630       intEncoder = intEncoder + 1;
 631     }
 632     else {
 633       intEncoder = intEncoder - 1;
 634     };
 635   }
 636 }