changed to match common Griduino file

examples/DAC_timer_v4/hardware.h

@@ -54,6 +54,7 @@ On-board lights:
 
 // TFT display and SD card share the hardware SPI interface, and have
 // separate 'select' pins to identify the active device on the bus.
+
 #if defined(SAMD_SERIES)
 // Adafruit Feather M4 Express pin definitions
 // To compile for Feather M0/M4, install "additional boards manager"
@@ -67,53 +68,80 @@ On-board lights:
 #define SD_CD  10   // SD card detect pin - Feather
 #define SD_CCS 11   // SD card select pin - Feather
 
-#elif defined(ARDUINO_AVR_MEGA2560)
-#define TFT_BL 6    // TFT backlight
-#define SD_CCS 7    // SD card select pin - Mega
-#define SD_CD  8    // SD card detect pin - Mega
-#define TFT_DC 9    // TFT display/command pin
-#define TFT_CS 10   // TFT chip select pin
+#elif defined(ARDUINO_ADAFRUIT_FEATHER_RP2040)
+// Ref: https://arduino-pico.readthedocs.io/en/latest/index.html
+// Adafruit Feather_RP2040 pin definitions
+// To compile for Feather_RP2040, install "additional boards manager"
+// https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
+
+#define TFT_BL 4    // TFT backlight
+#define TFT_CS 5    // TFT chip select pin
+#define TFT_DC 12   // TFT display/command pin
 #define BMP_CS 13   // BMP388 sensor, chip select
 
+#define SD_CD  10   // SD card detect pin - Feather
+#define SD_CCS 11   // SD card select pin - Feather
+
 #else
 #warning You need to define pins for your SPI bus hardware
 #endif
 
 // ------- TFT 4-Wire Resistive Touch Screen configuration parameters
-// For touch point precision, we need to know the resistance
-// between X+ and X- Use any multimeter to read it
-#define XP_XM_OHMS 295   // Resistance in ohms between X+ and X- to calibrate touch pressure
-                         // measure this with an ohmmeter while Griduino turned off
-
-#define TOUCHPRESSURE 200   // Minimum pressure threshhold considered an actual "press"
-
-#define X_MIN_OHMS 150   // Expected range on touchscreen's X-axis readings
-#define X_MAX_OHMS 880
-#define Y_MIN_OHMS 110   // Expected range on touchscreen's Y-axis readings
-#define Y_MAX_OHMS 860
+#define XP_XM_OHMS 0   // Set to zero to receive raw pressure measurements
+
+#define START_TOUCH_PRESSURE 200   // Minimum pressure threshold considered start of "press"
+#define END_TOUCH_PRESSURE   50    // Maximum pressure threshold required before end of "press"
+
+#define X_MIN_OHMS 100   // Expected range on touchscreen's X-axis readings
+#define X_MAX_OHMS 900
+#define Y_MIN_OHMS 100   // Expected range on touchscreen's Y-axis readings
+#define Y_MAX_OHMS 900
+
+#if defined(ARDUINO_ADAFRUIT_FEATHER_RP2040)
+// ---------- Touch Screen pins - Adafruit Feather RP2040
+#define PIN_XM A2   // Touchscreen X- must be an analog pin, use "An" notation
+#define PIN_YP A3   // Touchscreen Y+ must be an analog pin, use "An" notation
+#define PIN_XP 24   // Touchscreen X+ can be a digital pin
+#define PIN_YM 25   // Touchscreen Y- can be a digital pin
+
+// ---------- Audio output pins
+//  #define DAC_PIN     0   // do not use - RP2040 has no DAC
+//  #define PIN_SPEAKER 0   // do not use - RP2040 has no DAC
+#else
+// ---------- Touch Screen pins - Feather M4
+#define PIN_XP      A3     // Touchscreen X+ can be a digital pin
+#define PIN_XM      A4     // Touchscreen X- must be an analog pin, use "An" notation
+#define PIN_YP      A5     // Touchscreen Y+ must be an analog pin, use "An" notation
+#define PIN_YM      9      // Touchscreen Y- can be a digital pin
+// ---------- Audio output pins
+#define DAC_PIN     DAC0   // onboard DAC0 == pin A0
+#define PIN_SPEAKER DAC0   // uses DAC
+#endif
 
-// ---------- Touch Screen
-#define PIN_XP A3   // Touchscreen X+ can be a digital pin
-#define PIN_XM A4   // Touchscreen X- must be an analog pin, use "An" notation
-#define PIN_YP A5   // Touchscreen Y+ must be an analog pin, use "An" notation
-#define PIN_YM 9    // Touchscreen Y- can be a digital pin
+// ---------- Battery voltage sensor
+#if defined(ARDUINO_ADAFRUIT_FEATHER_RP2040)
+#define BATTERY_ADC A1
+#endif
 
-// ---------- Feather's onboard lights
+// ---------- Feather RP2040 onboard led
+#if defined(ARDUINO_ADAFRUIT_FEATHER_RP2040)
+#define RED_LED 25   // diagnostics RED LED
+#else
 #define RED_LED 13   // diagnostics RED LED
-// define PIN_LED 13                    // already defined in Feather's board variant.h
+#endif
 
 // ---------- neopixel
 #define NUMPIXELS 1   // Feather M4 has one NeoPixel on board
-// efine PIN_NEOPIXEL 8     // already defined in Feather's board variant.h
-
-// ---------- Audio output
-#define DAC_PIN     DAC0   // onboard DAC0 == pin A0
-#define PIN_SPEAKER DAC0   // uses DAC
+// define PIN_NEOPIXEL 8     // already defined in Feather's board variant.h
 
 // ---------- Digital potentiometer
-// Adafruit Feather M4 Express pin definitions
+#if defined(ARDUINO_ADAFRUIT_FEATHER_RP2040)
+// todo - Griduino PCB v7 uses volume control on I2C
+#else
+// Griduino PCB v7 uses volume control DS1804 on SPI
 #define PIN_VCS A1   // volume chip select
 #define PIN_VUD A2   // volume up/down
+#endif
 
 // Adafruit ItsyBitsy M4 Express potentiometer wiring
 #if defined(ADAFRUIT_ITSYBITSY_M4_EXPRESS)