-
Notifications
You must be signed in to change notification settings - Fork 2
/
adafruit_tt21100.py
103 lines (79 loc) · 2.97 KB
/
adafruit_tt21100.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
# SPDX-FileCopyrightText: Copyright (c) 2022 Scott Shawcroft for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
`adafruit_tt21100`
================================================================================
Basic driver for TT21100 touchscreen drivers
* Author(s): Scott Shawcroft
Implementation Notes
--------------------
**Hardware:**
* `Espressif ESP32-S3 Box <https://www.adafruit.com/product/5290>`_
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the supported boards:
https://circuitpython.org/downloads
* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
"""
__version__ = "0.0.0+auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_TT21100.git"
import array
import struct
import time
from adafruit_bus_device.i2c_device import I2CDevice
try:
from typing import List
except ImportError:
pass
# This is based on:
# https://github.com/espressif/esp-box/blob/master/components/i2c_devices/touch_panel/tt21100.c
class TT21100:
"""
A driver for the TT21100 capacitive touch sensor.
"""
def __init__(self, i2c, address=0x24, irq_pin=None):
self._i2c = I2CDevice(i2c, address)
self._irq_pin = irq_pin
self._bytes = bytearray(28)
self._data_len = array.array("H", [0])
# Poll for start up.
with self._i2c as i2c_transaction:
while self._data_len[0] != 0x0000:
i2c_transaction.readinto(self._data_len)
time.sleep(0.02)
@property
def touched(self) -> int:
"""Returns the number of touches currently detected"""
with self._i2c as i2c:
i2c.readinto(self._data_len)
# Throw away packets that are header only because they don't actually
# have any touches
if self._data_len[0] == 7:
i2c.readinto(self._bytes, end=7)
if self._data_len[0] % 10 == 7:
return self._data_len[0] // 10
return 0
@property
def touches(self) -> List[dict]:
"""
Returns a list of touchpoint dicts, with 'x' and 'y' containing the
touch coordinates, and 'id' as the touch # for multitouch tracking
"""
touchpoints = []
self._bytes[2] = 0
while self._bytes[2] != 1:
with self._i2c as i2c:
i2c.readinto(self._data_len)
# Empty queue
if self._data_len[0] in (0, 2):
return []
i2c.readinto(self._bytes, end=self._data_len[0])
for i in range(self._data_len[0] // 10):
touch_id, x, y, pressure = struct.unpack_from(
"xBHHBxxx", self._bytes, offset=10 * i + 7
)
touch_id = touch_id & 0x1F
point = {"x": x, "y": y, "id": touch_id, "pressure": pressure}
touchpoints.append(point)
return touchpoints