uncannyeyes - only one eye possible?

[AloisKlingler]

Hi,

I have two ST7735 which I wanted to drive with a esp8266, both displays are working fine.

i tried to adapt the example eps8266_uncannyeyes like the adafruit uncannyeyes is for two displays with the for-loop:

void setup(void) {
  uint8_t e;

  Serial.begin(250000);
  randomSeed(analogRead(A0)); // Seed random() from floating analog input

  for(e=0; e<NUM_EYES; e++) {
    Serial.print("Create display #"); Serial.println(e);
  }

  eye[e].tft.init();
  eye[e].tft.fillScreen(TFT_BLACK);
  eye[e].tft.setRotation(1);

but now the esp8266 crashes with exception28:

Create display #1

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

Exception (28):
epc1=0x4020dd89 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000020 depc=0x00000000

>>>stack>>>

ctx: cont
sp: 3ffffdf0 end: 3fffffc0 offset: 0190
3fffff80:  3fffdad0 3ffe861c 3ffee64c 3ffee6b8  
3fffff90:  3fffdad0 3ffe861c 3ffee624 4020107e  
3fffffa0:  feefeffe 00000000 3ffee678 40204c44  
3fffffb0:  feefeffe feefeffe 3ffe84f8 40100c39  
<<<stack<<<

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

anything I can do here?

Thanks!

Best regards Alois

[Bodmer]

e has been increased in the for loop and this exits with e set to 2, reset e to a sensible number after the for loop!

[AloisKlingler]

Hello @Bodmer ,

thanks. So, the crash was a misplaced bracket. Sorry, was too late for beeing able to see this.

But, the main issue remains: Only one display is in use, it is always the one which is cabled to D8 on the nodeMCU.

I originally tought it is only necessary to initiate the second displays, that's why I placed the loop:

now the loop looks like this:

  for(e=0; e<NUM_EYES; e++) {
    Serial.print("Create display #"); Serial.println(e);
    eye[e].tft.init();
    eye[e].tft.fillScreen(TFT_BLACK);
    eye[e].tft.setRotation(1);
  }

the eye-struct:

struct {
  TFT_eSPI tft; // OLED/eye[e].tft object
  uint8_t     cs;      // Chip select pin
  eyeBlink    blink;   // Current blink state
} eye[] = { // OK to comment out one of these for single-eye display:
  TFT_eSPI(),SELECT_L_PIN,{WINK_L_PIN,NOBLINK},
  TFT_eSPI(),SELECT_R_PIN,{WINK_R_PIN,NOBLINK},
};

I can see on serial console, it entering twice the loop.

SELECT_L_PIN and SELECT_R_PIN are to D6 and D8.

The display which is connected to D8 is flickering, so it shows left and right eye. In function frame(... I placed a serial output for eyeIndex (function draweye(... is called from there), it show me swapping 0 and 1, so it tries to draw both eyes. user_setup.h is adapted according to my displays: #define ST7735_DRIVER / #define TFT_WIDTH 128 / #define TFT_HEIGHT 160 / #define ST7735_GREENTAB nothing else changed. I have also tried to comment-out there the #define TFT_CS PIN_D8 - but it did not change anything (it still compiled and installed, same eye behavior, only one display is used). user_setup_select.h is left default.

Do you have an idea what I am doing wrong?

Thanks!

Best regards Alois

[AloisKlingler]

I do not get why the CS-Pin is not honored.

with the following code both displays are initialized, but still they follow both D8. I have to comment-out the second eye[] struct to have it working now for two displays, but it does not look as nice as if could look, with mirrored stuff and so on...

  for(e=0; e<NUM_EYES; e++) {
    pinMode(eye[e].cs, OUTPUT);
    digitalWrite(eye[e].cs, HIGH);
  }

  for(e=0; e<NUM_EYES; e++) {
    Serial.print("Create display #"); Serial.println(e);
    digitalWrite(eye[e].cs, LOW);
    eye[e].tft.init();
    eye[e].tft.fillScreen(TFT_BLACK);
    eye[e].tft.setRotation(0);
    digitalWrite(eye[e].cs, HIGH);
  }

also I have added in the draweye function the digitalWrite(eye[e].cs, LOW); and digitalWrite(eye[e].cs, HIGH); accordingly.

Any help is appreciated.

Thanks :-)

Best regards Alois

[Bodmer]

When you take control of the chip select in you code you must comment out the define in the setup file otherwise TFT_eSPI will always control that pin.

[AloisKlingler]

I did, but it does not help. Is a special recompile necessary if the header of the lib is changed?

[Bodmer]

Always set the chip select to a high level when a screen update has been completed.

[AloisKlingler]

I do, in drawEye:

void drawEye(
...
  //eye[e].tft.setAddrWindow(319-127, 0, 319, 127);
  eye[e].tft.setAddrWindow(0, 0, 128, 128);

  digitalWrite(eye[e].cs, LOW);                       // Chip select
  digitalWrite(DISPLAY_DC, HIGH);                     // Data mode

  // Now just issue raw 16-bit values for every pixel...

  scleraXsave = scleraX; // Save initial X value to reset on each line
...
        }
      }
      *(pbuffer + pixels++) = p>>8 | p<<8;

      if (pixels >= BUFFER_SIZE) { yield(); eye[e].tft.pushColors((uint8_t*)pbuffer, pixels*2); pixels = 0;}
    }
  }

   if (pixels) { eye[e].tft.pushColors(pbuffer, pixels); pixels = 0;}

  digitalWrite(eye[e].cs, HIGH);                       // Chip unselect

}

[Bodmer]

D8 is the hardware chip select for the port so perhaps the SPI library has a preference to always use that pin. Try allocating the chip selects to pins other than D8. For tests I suggest GPIO D4 and D5.

[AloisKlingler]

sadly this does not work either. it get's better for one eye (rendered correctly now), but not for the other (still flickering as it is rendered for left and right). I tried several combinations of D2, D1 and D6. D8 is always used (as you wrote).

Thanks for your help, very appreciated.

[Bodmer]

Have you commented out TFT_CS completely in the setup?

Run the diagnostic "Read_User_Setup" to check no TFT_CS pin has been allocated.

[Bodmer]

I have added 2 new examples:

• Animated_Eyes_1 for a single display (240x320 minimum) with 2 eyes
• Animated_Eyes_2 driving two ST7735 128x128 displays

[Bodmer]

Info here.

[AloisKlingler]

Hello @Bodmer ,

sorry for late replying - thanks for your instructable project.

With your latest library and the sample 2-eye-script it works. one thing (maybe this information helps somebody): I must not use D8 (altough in User_Setup.h disabled: #define TFT_CS ) as soon as I use D8 either the display on D8 renders both eyes or stays blank. As soon as I use e.g. D1 / D2 it works perfect.

ESP8266 performance: 21fps with 80MHz, 30fps with 160MHz. Used two ST7735_GREENTAB with 160x128 in User_Setup.h

best regards Alois

[InvisiKing]

Hi @Bodmer, I am using the ESP32-C3 with the LCD screen connected directly to it, And I want to flip the Eye Eyelid from left to right, how do I go about doing that, the rotation just rotate the eye 90 degrees with each setting, but i need the eye flipped from left to right, as i am using independent ESP32-C3 with the LCD screen for each eye.