Add quad encoder Feather ESP32 S2 TFT example (#92)

* add example

* add feather esp32s2 tft to ci check

.github/workflows/githubci.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        arduino-platform: ["uno", "leonardo", "mega2560", "zero", "esp8266", "esp32", "metro_m4", "nrf52840"]
+        arduino-platform: ["uno", "leonardo", "mega2560", "zero", "esp8266", "esp32", "feather_esp32s2_tft", "metro_m4", "nrf52840"]
 
     runs-on: ubuntu-latest
 

examples/encoder/PID5752_QuadEncoder_TFTDemo/PID5752_QuadEncoder_TFTDemo.ino

@@ -0,0 +1,143 @@
+/*
+ * This is a demo for a Feather ESP32-S2 TFT connected to a Quad
+ * Rotary Encoder board
+ * https://www.adafruit.com/product/5300
+ * https://www.adafruit.com/product/5752
+ * 
+ */
+#include "Adafruit_seesaw.h"
+#include <seesaw_neopixel.h>
+#include <Adafruit_ST7789.h> 
+#include <Fonts/FreeSans12pt7b.h>
+// we hvae loooots of PSRAM so lets use a GFX canvas for flicker-free graphics!
+GFXcanvas16 canvas(240, 135);
+Adafruit_ST7789 display = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
+
+
+#define SS_NEO_PIN       18
+#define SS_ENC0_SWITCH   12
+#define SS_ENC1_SWITCH   14
+#define SS_ENC2_SWITCH   17
+#define SS_ENC3_SWITCH   9
+
+#define SEESAW_ADDR      0x49
+
+Adafruit_seesaw ss = Adafruit_seesaw(&Wire);
+seesaw_NeoPixel pixels = seesaw_NeoPixel(4, SS_NEO_PIN, NEO_GRB + NEO_KHZ800);
+
+int32_t enc_positions[4] = {0, 0, 0, 0};
+
+void setup() {
+  Serial.begin(115200);
+  //while (!Serial) delay(10);
+
+  pinMode(TFT_BACKLITE, OUTPUT);
+  digitalWrite(TFT_BACKLITE, LOW);
+
+  // turn on the TFT / I2C power supply
+  pinMode(TFT_I2C_POWER, OUTPUT);
+  digitalWrite(TFT_I2C_POWER, HIGH);
+  delay(10);
+
+  Serial.println("Looking for seesaw!");
+
+  if (! ss.begin(SEESAW_ADDR) || !pixels.begin(SEESAW_ADDR)) {
+    Serial.println("Couldn't find seesaw on default address");
+    while(1) delay(10);
+  }
+  Serial.println("seesaw started");
+  uint32_t version = ((ss.getVersion() >> 16) & 0xFFFF);
+  if (version  != 5752){
+    Serial.print("Wrong firmware loaded? ");
+    Serial.println(version);
+    while(1) delay(10);
+  }
+  Serial.println("Found Product 5752");
+
+  ss.pinMode(SS_ENC0_SWITCH, INPUT_PULLUP);
+  ss.pinMode(SS_ENC1_SWITCH, INPUT_PULLUP);
+  ss.pinMode(SS_ENC2_SWITCH, INPUT_PULLUP);
+  ss.pinMode(SS_ENC3_SWITCH, INPUT_PULLUP);
+  ss.setGPIOInterrupts(1UL << SS_ENC0_SWITCH | 1UL << SS_ENC1_SWITCH | 
+                       1UL << SS_ENC2_SWITCH | 1UL << SS_ENC3_SWITCH, 1);
+
+
+  // get starting positions
+  for (int e=0; e<4; e++) {
+    enc_positions[e] = ss.getEncoderPosition(e);
+    ss.enableEncoderInterrupt(e);
+  }
+
+  Serial.println("Turning on interrupts");
+
+  pixels.setBrightness(255);
+  pixels.show(); // Initialize all pixels to 'off'
+
+  display.init(135, 240);           // Init ST7789 240x135
+  display.setRotation(3);
+  display.fillScreen(ST77XX_BLUE);
+  digitalWrite(TFT_BACKLITE, HIGH);
+
+  canvas.setFont(&FreeSans12pt7b);
+  canvas.setTextColor(ST77XX_WHITE);  
+}
+
+uint8_t switch_pins[] = {SS_ENC0_SWITCH, SS_ENC1_SWITCH, SS_ENC2_SWITCH, SS_ENC3_SWITCH};
+
+void loop() {
+  bool changed = false;
+  canvas.fillScreen(ST77XX_BLACK);
+  canvas.setCursor(0, 25);
+  canvas.setTextColor(ST77XX_WHITE);
+  //canvas.println("Quad Encoder QT Demo");
+
+  for (int e=0; e<4; e++) {
+    int32_t new_enc_position = ss.getEncoderPosition(e);
+    // did we move around?
+    if (enc_positions[e] != new_enc_position) {
+      Serial.print("Rot. #");
+      Serial.print(e);
+      Serial.print(" -> ");
+      Serial.println(new_enc_position);      // display new position
+      enc_positions[e] = new_enc_position;      // and save for next round
+
+      // change the neopixel color, mulitply the new positiion by 4 to speed it up
+      pixels.setPixelColor(e, Wheel((new_enc_position*4) & 0xFF));
+      pixels.show();
+      changed = true;
+    }
+    canvas.setTextColor(ST77XX_WHITE);
+    canvas.print("Rotary #");
+    canvas.print(e);
+    canvas.print(": ");
+    canvas.print(enc_positions[e]);
+
+    if (! ss.digitalRead(switch_pins[e])) {
+       Serial.print("ENC");
+       Serial.print("e");
+       Serial.println("pressed!");
+       canvas.setTextColor(ST77XX_RED);
+       canvas.print(" DOWN");
+       changed = true;
+    }
+    canvas.println();
+  }
+
+  if (changed) {
+    display.drawRGBBitmap(0, 0, canvas.getBuffer(), 240, 135);
+  }
+}
+
+
+uint32_t Wheel(byte WheelPos) {
+  WheelPos = 255 - WheelPos;
+  if (WheelPos < 85) {
+    return seesaw_NeoPixel::Color(255 - WheelPos * 3, 0, WheelPos * 3);
+  }
+  if (WheelPos < 170) {
+    WheelPos -= 85;
+    return seesaw_NeoPixel::Color(0, WheelPos * 3, 255 - WheelPos * 3);
+  }
+  WheelPos -= 170;
+  return seesaw_NeoPixel::Color(WheelPos * 3, 255 - WheelPos * 3, 0);
+}