Adds cst328 touch driver

Author: kdschlosser

api_drivers/common_api_drivers/indev/cst328.py

@@ -0,0 +1,154 @@
+from micropython import const  # NOQA
+import pointer_framework
+import time
+import machine  # NOQA
+
+
+I2C_ADDR = 0x1A
+BITS = 8
+
+# 4 byte read
+# PROJECT_ID = byte2 << 8 | byte3
+# CHIP_TYPE = byte0 << 8 | byte1
+_ID_REG = const(0xD204)
+
+# BYTE 3:FW_MAJOR
+# BYTE 2:FW_MINOR
+# BYTE 1 ~ BYTE 0:FW_BUILD
+# 4 byte read
+# MAJOR = byte0
+# MINOR = byte1
+# MICRO = byte2 << 8 | byte3
+_FW_VERSION_REG = const(0xD208)
+
+
+_MODE_NORMAL_REG = const(0xD109)
+
+
+# touch information register
+# MODE_NORMAL
+# BYTE0:
+# BITS 0 - 3: Touch state (0x06) == touched
+# BITS 4 - 7: N/A
+
+# BYTE1, BYTE2, BYTE3
+# BYTE1: BIT 7 ~ BIT 0: X high 8 bits
+# BYTE2: BIT 7 ~ BIT 0: Y high 8 bits
+# BYTE3: BITS 0 - 3: Y low 4 bits, BITS 4 - 7 X low 4 bits
+# x = BYTE1 << 4 | BYTE3 >> 4
+# y = BYTE2 << 4 | BYTE3 & 0x0F
+
+# BYTE4:
+# BITS 0 - 7: Touch pressure
+
+# BYTE5:
+# BITS 0 - 3: Finger count
+# BITS 4 - 7: N/A
+_TOUCH_DATA_REG = const(0xD000)
+_TOUCH_STATE_MASK = const(0x0F)
+_TOUCH_STATE_PRESSED = const(0x06)
+_TOUCH_COUNT_MASK = const(0x0F)
+
+
+class CST328(pointer_framework.PointerDriver):
+
+    def _read_reg(self, reg, num_bytes):
+        self._tx_buf[0] = reg >> 8
+        self._tx_buf[1] = reg & 0xFF
+
+        self._rx_buf[:num_bytes] = bytearray([0x00] * num_bytes)
+
+        self._device.write_readinto(self._tx_mv[:2], self._rx_mv[:num_bytes])
+
+    def _write_reg(self, reg, value=None):
+        self._tx_buf[0] = reg >> 8
+        self._tx_buf[1] = reg & 0xFF
+
+        if value is None:
+            self._device.write(self._tx_mv[:2])
+        else:
+            self._tx_buf[2] = value
+            self._device.write(self._tx_mv[:3])
+
+    def __init__(
+        self,
+        device,
+        reset_pin=None,
+        touch_cal=None,
+        startup_rotation=pointer_framework.lv.DISPLAY_ROTATION._0,
+        debug=False
+    ):
+        self._tx_buf = bytearray(2)
+        self._tx_mv = memoryview(self._tx_buf)
+        self._rx_buf = bytearray(6)
+        self._rx_mv = memoryview(self._rx_buf)
+
+        self._device = device
+
+        if not isinstance(reset_pin, int):
+            self._reset_pin = reset_pin
+        else:
+            self._reset_pin = machine.Pin(reset_pin, machine.Pin.OUT)
+
+        if self._reset_pin:
+            self._reset_pin.value(1)
+
+        self.hw_reset()
+
+        self._read_reg(_ID_REG, 4)
+        chip_id = (self._rx_buf[0] << 8) | self._rx_buf[1]
+        project_id = (self._rx_buf[2] << 8) | self._rx_buf[3]
+
+        print(f'Chip ID: 0x{hex(chip_id)[2:].upper()}')
+        print(f'Proj ID: 0x{hex(project_id)[2:].upper()}')
+
+        self._read_reg(_FW_VERSION_REG, 4)
+        version = f'{self._rx_buf[0]}.{self._rx_buf[1]}.{(self._rx_buf[2] << 8) | self._rx_buf[3]}'
+        print('FW Version:', version)
+
+        self._write_reg(_MODE_NORMAL_REG)
+
+        self._touch_thresh = 10
+
+        super().__init__(
+            touch_cal=touch_cal, startup_rotation=startup_rotation, debug=debug
+        )
+
+    @property
+    def touch_threshold(self):
+        return self._touch_thresh
+
+    @touch_threshold.setter
+    def touch_threshold(self, value):
+        if value < 1:
+            value = 1
+        elif value > 255:
+            value = 255
+        self._touch_thresh = value
+
+    def hw_reset(self):
+        if self._reset_pin is None:
+            return
+
+        self._reset_pin(0)
+        time.sleep_ms(1)  # NOQA
+        self._reset_pin(1)
+        time.sleep_ms(50)  # NOQA
+
+    def _get_coords(self):
+        self._read_reg(_TOUCH_DATA_REG, 6)
+
+        touch_count = self._rx_buf[5] & _TOUCH_COUNT_MASK
+        if touch_count:
+            if self._rx_buf[0] & _TOUCH_STATE_MASK == _TOUCH_STATE_PRESSED:
+                state = self.PRESSED
+
+                if self._rx_buf[4] < self._touch_thresh:
+                    return None
+            else:
+                state = self.RELEASED
+
+            x = (self._rx_buf[1] << 4) | (self._rx_buf[3] >> 4)
+            y = (self._rx_buf[2] << 4) | (self._rx_buf[3] & 0x0F)
+
+            return state, x, y