TTGO T-Watch-2020 Simple touch drawing example

examples/watch_draw.py

+'''
+watch_draw.py: A very simple drawing program for the TTGO T-Watch-2020
+using the adafruit_focaltouch driver modified for micropython by franz schaefer
+from https://gitlab.com/mooond/t-watch2020-esp32-with-micropython
+'''
+
+import machine
+import axp202c
+import st7789
+import focaltouch
+import vga1_8x8 as font
+
+# color swatches
+COLORS = [
+    st7789.BLACK,
+    st7789.BLUE,
+    st7789.RED,
+    st7789.GREEN,
+    st7789.CYAN,
+    st7789.MAGENTA,
+    st7789.YELLOW,
+    st7789.WHITE]
+
+def main():
+    '''
+    Draw on screen using focaltouch sensor
+    '''
+    try:
+        # Turn on display backlight
+        axp = axp202c.PMU()
+        axp.enablePower(axp202c.AXP202_LDO2)
+
+        # initialize display spi port
+        spi = machine.SPI(
+            2,
+            baudrate=32000000,
+            polarity=1,
+            phase=0,
+            bits=8,
+            firstbit=0,
+            sck=machine.Pin(18, machine.Pin.OUT),
+            mosi=machine.Pin(19, machine.Pin.OUT))
+
+        # configure display
+        tft = st7789.ST7789(
+            spi,
+            240,
+            240,
+            cs=machine.Pin(5, machine.Pin.OUT),
+            dc=machine.Pin(27, machine.Pin.OUT),
+            backlight=machine.Pin(12, machine.Pin.OUT),
+            rotation=2)
+
+        # enable display and clear screen
+        tft.init()
+        tft.fill(st7789.BLACK)
+        tft.text(font, "Draw", 104, 1, st7789.WHITE)
+
+        # enable focaltouch touchscreen
+        touch_i2c = machine.I2C(scl=machine.Pin(32), sda=machine.Pin(23))
+        touch = focaltouch.FocalTouch(touch_i2c)
+
+        color_index = 0
+        color = 0
+        # draw color swatches used to select color to draw
+        for color_index, color in enumerate(COLORS):
+            tft.fill_rect(color_index*30, 210, 30, 30, color)
+
+        # draw box around currently selected color
+        tft.rect(color_index*30, 210, 30, 30, st7789.WHITE)
+        tft.rect(color_index*30+1, 211, 28, 28, st7789.BLACK)
+        tft.rect(color_index*30+2, 212, 26, 26, st7789.BLACK)
+
+        while True:
+            # can be up to two touches
+            if touch.touched == 1:
+
+                # get x and y points of the first touch
+                p_x = touch.touches[0]['x']
+                p_y = touch.touches[0]['y']
+
+                # If point is in the lowest 30 rows of the screen
+                # change color to swatch pressed.
+                if p_y > 209:
+                    # remove box from around previous color swatch
+                    tft.rect(color_index*30, 210, 30, 30, color)
+                    tft.rect(color_index*30+1, 211, 28, 28, color)
+                    tft.rect(color_index*30+2, 212, 26, 26, color)
+
+                    # update new color
+                    color_index = p_x//30
+                    color = COLORS[color_index]
+
+                    # draw box around newly selected color swatch
+                    tft.rect(color_index*30, 210, 30, 30, st7789.WHITE)
+                    tft.rect(color_index*30+1, 211, 28, 28, st7789.BLACK)
+                    tft.rect(color_index*30+2, 212, 26, 26, st7789.BLACK)
+
+                else:
+                    # draw the pixel - would be better with lines
+                    tft.pixel(p_x, p_y, color)
+
+    finally:
+        # shutdown i2c
+        if 'touch_i2c' in locals():
+            touch_i2c.deinit()
+
+        # shutdown spi
+        if 'spi' in locals():
+            spi.deinit()
+
+        # turn off display backlight
+        axp.disablePower(axp202c.AXP202_LDO2)
+
+main()

lib/focaltouch.py

+# The MIT License (MIT)
+#
+# Copyright (c) 2017 ladyada for adafruit industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""
+`adafruit_focaltouch`
+====================================================
+
+CircuitPython driver for common low-cost FocalTech capacitive touch chips.
+Currently supports FT6206 & FT6236.
+
+* Author(s): ladyada
+
+* adopted for micropython => franz schaefer (mond)
+
+Implementation Notes
+--------------------
+
+**Hardware:**
+
+* Adafruit `2.8" TFT LCD with Cap Touch Breakout Board w/MicroSD Socket
+  <http://www.adafruit.com/product/2090>`_ (Product ID: 2090)
+
+* Adafruit `2.8" TFT Touch Shield for Arduino w/Capacitive Touch
+  <http://www.adafruit.com/product/1947>`_ (Product ID: 1947)
+
+**Software and Dependencies:**
+
+* Adafruit CircuitPython firmware for the ESP8622 and M0-based boards:
+  https://github.com/adafruit/circuitpython/releases
+* Adafruit's Bus Device library (when using I2C/SPI):
+  https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
+"""
+
+# imports
+
+try:
+    import struct
+except ImportError:
+    import ustruct as struct
+
+from machine import I2C
+from micropython import const
+
+
+_FT6206_DEFAULT_I2C_ADDR = 0x38
+
+_FT6XXX_REG_DATA = const(0x00)
+_FT6XXX_REG_NUMTOUCHES = const(0x02)
+_FT6XXX_REG_THRESHHOLD = const(0x80)
+_FT6XXX_REG_POINTRATE = const(0x88)
+_FT6XXX_REG_LIBH = const(0xA1)
+_FT6XXX_REG_LIBL = const(0xA2)
+_FT6XXX_REG_CHIPID = const(0xA3)
+_FT6XXX_REG_FIRMVERS = const(0xA6)
+_FT6XXX_REG_VENDID = const(0xA8)
+_FT6XXX_REG_RELEASE = const(0xAF)
+
+
+class FocalTouch:
+    """
+    A driver for the FocalTech capacitive touch sensor.
+    """
+
+    _debug = False
+    chip = None
+
+    def __init__(self, i2c, address=_FT6206_DEFAULT_I2C_ADDR, debug=False):
+        self.bus = i2c
+        self.address = address 
+        self._debug = debug
+
+        chip_data = self._read(_FT6XXX_REG_LIBH, 8)
+        lib_ver, chip_id, _, _, firm_id, _, vend_id = struct.unpack(
+            ">HBBBBBB", chip_data
+        )
+
+        if debug:
+            print("Vendor ID %02x" % vend_id)
+
+        self.vend_id=vend_id
+        if chip_id == 0x06:
+            self.chip = "FT6206"
+        elif chip_id == 0x64:
+            self.chip = "FT6236"
+        elif debug:
+            print("Chip Id: %02x" % chip_id)
+
+        if debug:
+            print("Library vers %04X" % lib_ver)
+            print("Firmware ID %02X" % firm_id)
+            print("Point rate %d Hz" % self._read(_FT6XXX_REG_POINTRATE, 1)[0])
+            print("Thresh %d" % self._read(_FT6XXX_REG_THRESHHOLD, 1)[0])
+            
+
+    @property
+    def touched(self):
+        """ Returns the number of touches currently detected """
+        return self._read(_FT6XXX_REG_NUMTOUCHES, 1)[0]
+
+    # pylint: disable=unused-variable
+    @property
+    def touches(self):
+        """
+        Returns a list of touchpoint dicts, with 'x' and 'y' containing the
+        touch coordinates, and 'id' as the touch # for multitouch tracking
+        """
+        touchpoints = []
+        data = self._read(_FT6XXX_REG_DATA, 32)
+
+        for i in range(2):
+            point_data = data[i * 6 + 3 : i * 6 + 9]
+            if all([i == 0xFF for i in point_data]):
+                continue
+            # print([hex(i) for i in point_data])
+            x, y, weight, misc = struct.unpack(">HHBB", point_data)
+            # print(x, y, weight, misc)
+            touch_id = y >> 12
+            x &= 0xFFF
+            y &= 0xFFF
+            point = {"x": x, "y": y, "id": touch_id}
+            touchpoints.append(point)
+        return touchpoints
+
+    def _read(self, reg, length):
+        """Returns an array of 'length' bytes from the 'register'"""
+        result = bytearray(length)
+        self.bus.readfrom_mem_into(self.address, reg, result)
+        if self._debug:
+            print("\t$%02X => %s" % (reg, [hex(i) for i in result]))
+        return result
+
+    def _write(self, reg, values):
+        """Writes an array of 'length' bytes to the 'register'"""
+        values = [(v & 0xFF) for v in values]
+        self.bus.writeto_mem(self.address,reg,bytes(values))
+        if self._debug:
+            print("\t$%02X <= %s" % (reg, [hex(i) for i in values]))