Update SetVCOM.ino

Author: mtoldi

examples/Inkplate10/Diagnostics/SetVCOM/SetVCOM.ino

@@ -1,42 +1,28 @@
 /**
  **************************************************
  *
- * @file        SetVCOM_Inkplate10.ino
- * @brief       WARNING! - VCOM voltage is written in EEPROM, which means it can be
- *              set a limited number of times, so don't run this sketch repeatedly!
- *              VCOM should be set once and then left as is.
- *
- *              This example:
- *                - Reads the current VCOM value from the panel
- *                - Shows it on screen with a grayscale test pattern (LVGL)
- *                - Lets you type a new VCOM value over Serial ([-5.00, 0.00] V)
- *                - Programs it into the panel EEPROM (and stores it in ESP32 EEPROM too)
+ * @file        SetVCOM.ino
+ * @brief       WARNING! - VCOM voltage is written in EEPROM, which means it can be set a limited number of times,
+ *              so don't run this sketch repeateadly! VCOM should be set once and then left as is.
  *
  * For info on how to quickly get started with Inkplate 10 visit:
  * https://soldered.com/documentation/inkplate/10/overview/
  *
- * WARNING: Each VCOM write wears panel EEPROM. Use sparingly.
- *
  * @authors     Soldered
  * @date        November 2025
  ***************************************************/
 
-#if !defined(ARDUINO_INKPLATE10) && !defined(ARDUINO_INKPLATE10V2)
-#error "Wrong board selection for this example, please select e-radionica Inkplate10 or Soldered Inkplate10 in the boards menu."
-#endif
 
 #include <EEPROM.h>
 #include <Inkplate-LVGL.h>
 #include <Wire.h>
 
-// Inkplate 10 in 3-bit grayscale mode
-Inkplate inkplate(INKPLATE_3BIT);
+Inkplate inkplate(INKPLATE_3BIT); // Create an object on Inkplate library and also set the grayscale to 3bit.
 
-double currentVCOM;          // Stores the current VCOM value read from panel
-const int EEPROMAddress = 0; // Keep address 0 for correct VCOM storage in ESP32 EEPROM
+double currentVCOM;         // Stores the current VCOM value stored on EEPROM
+const int EEPROMAddress=0;  // Should leave the address as it is for correct EEPROM reading later
 double vcomVoltage;
 
-// Forward declarations
 double readPanelVCOM();
 double getVCOMFromSerial(double *_vcom);
 uint8_t writeVCOMToEEPROM(double v);
@@ -46,214 +32,171 @@ void displayTestImage();
 void writeReg(uint8_t reg, float data);
 uint8_t readReg(uint8_t reg);
 
-void setup()
+void setup() 
 {
-    Serial.begin(115200);     // Start serial at 115200 baud
-    EEPROM.begin(512);        // Initialize ESP32 EEPROM
-    Wire.begin();             // Initialize I2C bus
-    inkplate.begin();         // Initialize Inkplate + LVGL backend
-
-    Serial.println("The optimal VCOM Voltage for your Inkplate's panel can sometimes");
-    Serial.println("be found written on the flat cable connector.");
-    Serial.println("Write VCOM voltage from epaper panel.");
-    Serial.println("Don't forget negative (-) sign!");
-    Serial.println("Use dot as the decimal point.");
-    Serial.println("For example: -1.23");
-    Serial.println();
-
-    // First screen: current VCOM + grayscale bars
-    displayTestImage();
+  Serial.begin(115200);     //Start serial at 115200 baud
+  EEPROM.begin(512);        //Initialize EEPROM
+  Wire.begin();             //Initialize I2C buss
+  inkplate.begin();          //Initialize the Inkplate 
+  Serial.println("The optimal VCOM Voltage for your Inkplate's panel can sometimes be found written on the flat cable connector");
+  Serial.println("Write VCOM voltage from epaper panel. \r\nDon't forget negative (-) sign!\r\nUse dot as the decimal point.\r\nFor example -1.23\n");
+  displayTestImage();
 }
 
-void loop()
-{
-    if (Serial.available())
-    {
-        // Read VCOM from Serial until it's in range [-5.0, 0.0]
-        do
-        {
-            getVCOMFromSerial(&vcomVoltage);
-            Serial.println(vcomVoltage, 2);
-
-            if (vcomVoltage < -5.0 || vcomVoltage > 0.0)
-            {
-                Serial.println("VCOM out of range! [-5.0, 0.0]");
-            }
-        } while (vcomVoltage < -5.0 || vcomVoltage > 0.0);
-
-        // Program the panel EEPROM
-        // Internal IO pin 6 is used as the TPS65186 VCOM programming status pin
-        inkplate.internalIO.pinMode(6, INPUT_PULLUP);
-
-        if (writeVCOMToEEPROM(vcomVoltage))
-        {
-            EEPROM.put(EEPROMAddress, vcomVoltage);
-            EEPROM.commit();
-        }
-
-        // Clear LVGL screen and redraw test image with updated VCOM value
-        lv_obj_clean(lv_scr_act());
-        displayTestImage();
+void loop() 
+{  
+  if (Serial.available()){
+    //Serial.println("Enter VCOM value, it must be [-5, 0]");
+    do{
+      getVCOMFromSerial(&vcomVoltage);
+      Serial.println(vcomVoltage, 2);
+      if(vcomVoltage < -5.0 || vcomVoltage > 0.0){
+        Serial.println("VCOM out of range! [-5, 0]");
+      }
+    }while(vcomVoltage <-5.0 || vcomVoltage > 0.0);
+
+    //Program the panel EEPROM
+    inkplate.internalIO.pinMode(6, INPUT_PULLUP);
+    if(writeVCOMToEEPROM(vcomVoltage)){
+      EEPROM.put(EEPROMAddress, vcomVoltage);
+      EEPROM.commit();
     }
+    lv_obj_clean(lv_scr_act());
+    displayTestImage();
+  }
 }
 
-// ----- VCOM helpers -----
-
 double readPanelVCOM()
 {
-    delay(10); // Give TPS65186 time so registers respond
-    uint8_t vcomL = readReg(0x03);         // Low 8 bits from register 0x03
-    uint8_t vcomH = readReg(0x04) & 0x01;  // Mask bit 0 (MSB of raw)
-    delay(10);
-    int raw = (vcomH << 8) | vcomL;        // 0 .. 511
-    return -(raw / 100.0);                 // VCOM in volts (negative)
+  delay(10); //Wake up TPS65186 so registers respond
+  uint8_t vcomL=readReg(0x03); // Read low 8 bits from register 0x03
+  uint8_t vcomH = readReg(0x04) & 0x01; // Read full byte, mask off all but bit 0 (MSB)
+  delay(10); //Power down driver
+  int raw=(vcomH << 8) | vcomL; //Value between 0 - 511
+  return -(raw/100.0);
 }
 
 double getVCOMFromSerial(double *_vcom)
 {
-    double vcom = 0;
-    char buff[32];
-    unsigned long start;
-
-    // Wait for first char
-    while (!Serial.available())
-        ;
-
-    start = millis();
-    int idx = 0;
-
-    // Collect characters for up to 500 ms idle gap
-    while ((millis() - start) < 500 && idx < (int)sizeof(buff) - 1)
-    {
-        if (Serial.available())
-        {
-            char c = Serial.read();
-            buff[idx++] = c;
-            start = millis();
-        }
+  double vcom=0;
+  char buff[32];
+  unsigned long start;
+  while (!Serial.available());
+  start=millis();
+  int idx=0;
+  while ((millis()-start)<500 && idx<sizeof(buff)-1){
+    if(Serial.available()){
+      char c=Serial.read();
+      buff[idx++]=c;
+      start=millis();
     }
-
-    buff[idx] = '\0';
-    sscanf(buff, "%lf", &vcom);
-    *_vcom = vcom;
-    return vcom;
+  }
+  buff[idx]='\0';
+  sscanf(buff, "%lf", &vcom);
+  *_vcom=vcom;
+  return vcom;
 }
 
 uint8_t writeVCOMToEEPROM(double v)
 {
-    // Build a 9-bit raw value (0 - 511)
-    int raw = int(abs(v) * 100) & 0x1FF;
-    uint8_t lsb = raw & 0xFF;
-    uint8_t msb = (raw >> 8) & 0x01;
-
-    // NOTE: With Inkplate-LVGL, power control is handled internally.
-    // We assume the TPS65186 is powered from inkplate.begin().
-
-    writeReg(0x03, lsb);
-    uint8_t r4 = readReg(0x04) & ~0x01;
-    writeReg(0x04, r4 | msb);
-    // Set bit 6 to trigger EEPROM programming
-    writeReg(0x04, (r4 | msb) | (1 << 6));
-
-    // Wait for VCOM programming to finish
-    while (inkplate.internalIO.digitalRead(6))
-    {
-        delay(1);
-    }
-
-    // Clear interrupt flag and clean registers
-    readReg(0x07);  // clear interrupt flag
-    writeReg(0x03, 0);
-    writeReg(0x04, 0);
-
-    // We skip explicit einkOff/einkOn here because those are private
-    // in the LVGL Inkplate10 driver and the driver takes care of power.
-
-    // Verify written value
-    uint8_t vL = readReg(0x03);
-    uint8_t vH = readReg(0x04) & 0x01;
-    int check = (vH << 8) | vL;
-
-    if (check != raw)
-    {
-        Serial.printf("Verification failed: got %d, want %d\n", check, raw);
-        return 0;
-    }
-
-    Serial.println("VCOM EEPROM PROGRAMMING OK");
-    return 1;
+  //Build a 9-bit raw value (0 - 511)
+  int raw=int(abs(v)*100)&0x1FF;
+  uint8_t lsb=raw & 0xFF;
+  uint8_t msb=(raw >> 8)&0x01;
+  
+  inkplate.einkOn();
+  delay(10);
+
+  writeReg(0x03, lsb);
+  uint8_t r4=readReg(0x04)&~0x01;
+  writeReg(0x04, r4 | msb);
+  writeReg(0x04, (r4 | msb) | (1 << 6));
+  while ( inkplate.internalIO.digitalRead(6) ) {
+    delay(1);
+  }
+  readReg(0x07);  // clear interrupt flag
+  writeReg(0x03, 0);
+  writeReg(0x04, 0);
+  inkplate.einkOff(); // WAKEUP low
+  delay(10);
+  inkplate.einkOn();  // WAKEUP high
+  delay(10);
+  uint8_t vL = readReg(0x03);
+  uint8_t vH = readReg(0x04) & 0x01;
+  int check = (vH << 8) | vL;
+  if (check != raw) {
+    Serial.printf("Verification failed: got %d, want %d\n", check, raw);
+    return 0;
+  }
+  Serial.println("VCOM EEPROM PROGRAMMING OK");
+  return 1;
 }
 
-// ----- TPS65186 I2C access -----
-
 void writeReg(uint8_t reg, float data)
 {
-    Wire.beginTransmission(0x48);
-    Wire.write(reg);
-    Wire.write((uint8_t)data);
-    Wire.endTransmission();
+  Wire.beginTransmission(0x48);
+  Wire.write(reg);
+  Wire.write((uint8_t)data);
+  Wire.endTransmission();
 }
 
 uint8_t readReg(uint8_t reg)
 {
-    Wire.beginTransmission(0x48);
-    Wire.write(reg);
-    Wire.endTransmission(false);
-    Wire.requestFrom((uint8_t)0x48, (uint8_t)1);
-    return Wire.read();
+  Wire.beginTransmission(0x48);
+  Wire.write(reg);
+  Wire.endTransmission(false);
+  Wire.requestFrom((uint8_t)0x48, (uint8_t)1);
+  return Wire.read();
 }
 
-// ----- LVGL helpers -----
-
 static inline int display_width()
 {
-    lv_display_t *disp = lv_disp_get_default();
-    return lv_display_get_horizontal_resolution(disp);
+  lv_display_t *disp = lv_disp_get_default();
+  return lv_display_get_horizontal_resolution(disp);
 }
 
 static inline int display_height()
 {
-    lv_display_t *disp = lv_disp_get_default();
-    return lv_display_get_vertical_resolution(disp);
+  lv_display_t *disp = lv_disp_get_default();
+  return lv_display_get_vertical_resolution(disp);
 }
 
-void displayTestImage()
+void displayTestImage() 
 {
-    inkplate.clearDisplay();
-    currentVCOM = readPanelVCOM();
-
-    // Top text: "Current VCOM: <value> V"
-    lv_obj_t *label = lv_label_create(lv_screen_active());
-    lv_label_set_text(label, "Current VCOM: ");
-    lv_obj_set_style_text_color(lv_screen_active(), lv_color_hex(0x000000), LV_PART_MAIN);
-    lv_obj_set_style_text_font(label, &lv_font_montserrat_28, 0);
-    lv_obj_align(label, LV_ALIGN_TOP_LEFT, 5, 5);
-
-    lv_obj_t *label2 = lv_label_create(lv_scr_act());
-    String vcomText = String(currentVCOM, 2) + " V";
-    lv_label_set_text(label2, vcomText.c_str());
-    lv_obj_set_style_text_color(label2, lv_color_hex(0x000000), 0);
-    lv_obj_set_style_text_font(label2, &lv_font_montserrat_28, 0);
-    lv_obj_align_to(label2, label, LV_ALIGN_OUT_RIGHT_MID, 5, 0);
-
-    // Grayscale gradient bars across the screen
-    for (int i = 0; i < 8; i++)
-    {
-        int x = (display_width() / 8) * i;
-
-        uint8_t v = (i * 255) / 7;
-        lv_color_t color = lv_color_make(v, v, v);
-
-        lv_obj_t *rect = lv_obj_create(lv_scr_act());
-        lv_obj_set_size(rect, display_width() / 8, display_height());
-        lv_obj_set_pos(rect, x, 40);
-        lv_obj_set_style_bg_color(rect, color, 0);
-        lv_obj_set_style_border_width(rect, 0, 0);
-        lv_obj_set_style_radius(rect, 0, 0);
-    }
-
-    // Push LVGL buffer to the e-paper
-    lv_tick_inc(50);
-    lv_timer_handler();
-    inkplate.display();
-}
+  inkplate.clearDisplay();
+  currentVCOM = readPanelVCOM();
+
+  /* Show text on the screen */
+  lv_obj_t *label = lv_label_create(lv_screen_active());
+  lv_label_set_text(label, "Current VCOM: ");
+  lv_obj_set_style_text_color(lv_screen_active(), lv_color_hex(0x000000), LV_PART_MAIN);
+  lv_obj_set_style_text_font(label,  &lv_font_montserrat_28, 0);
+  lv_obj_align(label, LV_ALIGN_TOP_LEFT, 5, 5);
+  
+  /* Display value */
+  lv_obj_t *label2 = lv_label_create(lv_scr_act());
+  lv_label_set_text(label2, String(currentVCOM, 2).c_str());
+  lv_obj_set_style_text_color(label2, lv_color_hex(0x000000), 0);
+  lv_obj_set_style_text_font(label2, &lv_font_montserrat_28, 0);
+  // Position label2 just to the right of label1
+  lv_obj_align_to(label2, label, LV_ALIGN_OUT_RIGHT_MID, 5, 0);
+
+  for (int i = 0; i < 8; i++) 
+  {
+    int x = (display_width() / 8) * i;
+
+    uint8_t v = (i * 255) / 7;
+    lv_color_t color = lv_color_make(v, v, v);
+
+    lv_obj_t *rect = lv_obj_create(lv_scr_act());
+    lv_obj_set_size(rect, display_width() / 8, display_height());
+    lv_obj_set_pos(rect, x, 40);
+    lv_obj_set_style_bg_color(rect, color, 0);
+    lv_obj_set_style_border_width(rect, 0, 0);  // Remove 'padding'
+    lv_obj_set_style_radius(rect, 0, 0);        // No round corners
+  }
+  // Update the display
+  lv_tick_inc(50);
+  lv_timer_handler();
+  inkplate.display();
+}