From 0297fe856aa185e6a1f45b97a2501834850c0119 Mon Sep 17 00:00:00 2001
From: Benjamin Zeiss <ben@zeiss.net>
Date: Wed, 2 Mar 2022 03:27:14 +0100
Subject: [PATCH] 8bit encoder detection + debounced button detection, numpy
 removal (#710)

* debounce interrupt events for rotary events and button presses with 400 microseconds by default.

* Massive improvements for the encoder detection. Removed numpy as a dependency.

* Debounce button presses which started to jump around.

* formatting cleanup.
---
 easyinstall.sh                                |  4 +-
 python/ctrlboard/README.md                    |  1 +
 python/ctrlboard/requirements.txt             |  3 +-
 .../src/ctrlboard_hw/ctrlboard_hw.py          | 42 +++++++++------
 python/ctrlboard/src/ctrlboard_hw/encoder.py  | 51 ++++++-------------
 .../src/ctrlboard_hw/hardware_button.py       |  1 +
 6 files changed, 47 insertions(+), 55 deletions(-)

diff --git a/easyinstall.sh b/easyinstall.sh
index 288fa308..58269dd8 100755
--- a/easyinstall.sh
+++ b/easyinstall.sh
@@ -992,8 +992,8 @@ function installRaScsiCtrlBoard() {
     updateRaScsiGit
 
     sudo apt-get update && sudo apt-get install libjpeg-dev libpng-dev libopenjp2-7-dev i2c-tools raspi-config -y </dev/null
-    # install numpy via apt to avoid compilation
-    sudo apt-get install python3-numpy python3-cbor2 -y </dev/null
+    # install python packages through apt that need compilation
+    sudo apt-get install python3-cbor2 -y </dev/null
 
     # enable i2c
     if [[ $(grep -c "^dtparam=i2c_arm=on" /boot/config.txt) -ge 1 ]]; then
diff --git a/python/ctrlboard/README.md b/python/ctrlboard/README.md
index 22c15cdb..60bc3863 100644
--- a/python/ctrlboard/README.md
+++ b/python/ctrlboard/README.md
@@ -47,6 +47,7 @@ the raspberry pi model and enable transitions only for the following pi models:
 The model detection can be overriden by adding a --transitions parameter to start.sh.
 
 ## Credits
+
 ### DejaVuSansMono-Bold.ttf
 * Source: https://dejavu-fonts.github.io
 * Distributed under DejaVu Fonts Lience (see DejaVu Fonts License.txt for full text)
diff --git a/python/ctrlboard/requirements.txt b/python/ctrlboard/requirements.txt
index 1437610b..58aa5346 100644
--- a/python/ctrlboard/requirements.txt
+++ b/python/ctrlboard/requirements.txt
@@ -7,5 +7,4 @@ RPi.GPIO==0.7.0
 protobuf==3.19.3
 unidecode==1.3.2
 smbus==1.1.post2
-# installed via apt to avoid lengthy compilation
-#numpy==1.21.5
+
diff --git a/python/ctrlboard/src/ctrlboard_hw/ctrlboard_hw.py b/python/ctrlboard/src/ctrlboard_hw/ctrlboard_hw.py
index 6600d7f0..e5486feb 100644
--- a/python/ctrlboard/src/ctrlboard_hw/ctrlboard_hw.py
+++ b/python/ctrlboard/src/ctrlboard_hw/ctrlboard_hw.py
@@ -1,10 +1,10 @@
 """Module providing the interface to the RaSCSI Control Board hardware"""
 # noinspection PyUnresolvedReferences
 import logging
-import RPi.GPIO as GPIO
-import numpy
-import smbus
+import time
 
+import RPi.GPIO as GPIO
+import smbus
 from ctrlboard_hw import pca9554multiplexer
 from ctrlboard_hw.hardware_button import HardwareButton
 from ctrlboard_hw.ctrlboard_hw_constants import CtrlBoardHardwareConstants
@@ -16,9 +16,10 @@ from observable import Observable
 # pylint: disable=too-many-instance-attributes
 class CtrlBoardHardware(Observable):
     """Class implements the RaSCSI Control Board hardware and provides an interface to it."""
-    def __init__(self, display_i2c_address, pca9554_i2c_address):
+    def __init__(self, display_i2c_address, pca9554_i2c_address, debounce_ms=200):
         self.display_i2c_address = display_i2c_address
         self.pca9554_i2c_address = pca9554_i2c_address
+        self.debounce_ms = debounce_ms
         self.rascsi_controlboard_detected = self.detect_rascsi_controlboard()
         log = logging.getLogger(__name__)
         log.info("RaSCSI Control Board detected: %s", str(self.rascsi_controlboard_detected))
@@ -53,7 +54,7 @@ class CtrlBoardHardware(Observable):
         self.pca_driver.write_configuration_register_port(CtrlBoardHardwareConstants.
                                                           PCA9554_PIN_LED_2,
                                                           PCA9554Multiplexer.PIN_ENABLED_AS_OUTPUT)
-        self.input_register_buffer = numpy.uint32(0)
+        self.input_register_buffer = 0
 
         # pylint: disable=no-member
         GPIO.setmode(GPIO.BCM)
@@ -97,6 +98,7 @@ class CtrlBoardHardware(Observable):
         self.rotary = Encoder(self.rotary_a, self.rotary_b)
         self.rotary.pos_prev = 0
         self.rotary.name = CtrlBoardHardwareConstants.ROTARY
+        self.rot_prev_state = 0b11
 
     # noinspection PyUnusedLocal
     # pylint: disable=unused-argument
@@ -113,11 +115,18 @@ class CtrlBoardHardware(Observable):
 
         value = button.state_interrupt
 
+        # ignore button press if debounce time is not reached
+        if button.last_press is not None:
+            elapsed = (time.time_ns() - button.last_press)/1000000
+            if elapsed < self.debounce_ms:
+                return
+
         if value != button.state and value is False:
             button.state = False
             self.notify(button)
             button.state = True
             button.state_interrupt = True
+            button.last_press = time.time_ns()
 
     def check_rotary_encoder(self, rotary):
         """Checks whether the rotary state has changed."""
@@ -150,19 +159,20 @@ class CtrlBoardHardware(Observable):
 
     def process_events(self):
         """Non-blocking event processor for hardware events (button presses etc.)"""
-        input_register_buffer_length = int(len(format(self.input_register_buffer, 'b'))/8)
-        if input_register_buffer_length <= 1:
-            return
-
         input_register_buffer = self.input_register_buffer
         self.input_register_buffer = 0
 
+        input_register_buffer_length = int(len(format(input_register_buffer, 'b'))/8)
+        if input_register_buffer_length < 1:
+            return
+
         for i in range(0, input_register_buffer_length):
             shiftval = (input_register_buffer_length-1-i)*8
             input_register = (input_register_buffer >> shiftval) & 0b11111111
 
             rot_a = self.button_value(input_register, 0)
             rot_b = self.button_value(input_register, 1)
+
             button_rotary = self.button_value(input_register, 5)
             button_1 = self.button_value(input_register, 2)
             button_2 = self.button_value(input_register, 3)
@@ -176,19 +186,21 @@ class CtrlBoardHardware(Observable):
             if button_rotary == 0:
                 self.rotary_button.state_interrupt = bool(button_rotary)
 
+            rot_tmp_state = 0b11
             if rot_a == 0:
-                self.rotary.enc_a.state_interrupt = bool(rot_a)
-
+                rot_tmp_state &= 0b10
             if rot_b == 0:
+                rot_tmp_state &= 0b01
+
+            if rot_tmp_state != self.rot_prev_state:
+                self.rot_prev_state = rot_tmp_state
+                self.rotary.enc_a.state_interrupt = bool(rot_a)
                 self.rotary.enc_b.state_interrupt = bool(rot_b)
+                self.check_rotary_encoder(self.rotary)
 
             self.check_button_press(self.rotary_button)
             self.check_button_press(self.button1)
             self.check_button_press(self.button2)
-            self.check_rotary_encoder(self.rotary)
-
-        self.rotary.state = 0b11
-        self.input_register_buffer = 0
 
     @staticmethod
     def detect_i2c_devices(_bus):
diff --git a/python/ctrlboard/src/ctrlboard_hw/encoder.py b/python/ctrlboard/src/ctrlboard_hw/encoder.py
index 0af34d7a..f5568f33 100644
--- a/python/ctrlboard/src/ctrlboard_hw/encoder.py
+++ b/python/ctrlboard/src/ctrlboard_hw/encoder.py
@@ -10,57 +10,36 @@ class Encoder:
         self.enc_a = enc_a
         self.enc_b = enc_b
         self.pos = 0
-        self.state = 0b0011
+        self.state = 0b00000000
         self.direction = 0
 
     def update(self):
         """Updates the internal attributes wrt. to the encoder position and direction."""
-        self.update2()
-
-    def update2(self):
-        """Primary method for detecting the direction"""
         value_enc_a = self.enc_a.state_interrupt
         value_enc_b = self.enc_b.state_interrupt
 
         self.direction = 0
-        state = self.state & 0b0011
+        state = self.state & 0b00111111
 
         if value_enc_a:
-            state |= 0b0100
+            state |= 0b01000000
         if value_enc_b:
-            state |= 0b1000
+            state |= 0b10000000
 
-        if state == 0b1011:
+        # clockwise pattern detection
+        if (state == 0b11010010 or state == 0b11001000 or state == 0b11011000 or
+                state == 0b11010001 or state == 0b11011011 or state == 0b11100000 or
+                state == 0b11001011):
             self.pos += 1
             self.direction = 1
-
-        if state == 0b0111:
+            self.state = 0b00000000
+            return
+        # counter-clockwise pattern detection
+        elif (state == 0b11000100 or state == 0b11100100 or state == 0b11100001 or
+              state == 0b11000111 or state == 0b11100111):
             self.pos -= 1
             self.direction = -1
+            self.state = 0b00000000
+            return
 
         self.state = state >> 2
-
-        self.enc_a.state_interrupt = True
-        self.enc_b.state_interrupt = True
-
-    def update1(self):
-        """Secondary, less well working method to detect the direction"""
-        if self.enc_a.state_interrupt is True and self.enc_b.state_interrupt is True:
-            return
-
-        if self.enc_a.state_interrupt is False and self.enc_b.state_interrupt is False:
-            self.enc_a.state_interrupt = True
-            self.enc_b.state_interrupt = True
-            return
-
-        self.direction = 0
-
-        if self.enc_a.state_interrupt is False:
-            self.pos += 1
-            self.direction = 1
-        elif self.enc_a.state_interrupt is True:
-            self.pos -= 1
-            self.direction = -1
-
-        self.enc_a.state_interrupt = True
-        self.enc_b.state_interrupt = True
diff --git a/python/ctrlboard/src/ctrlboard_hw/hardware_button.py b/python/ctrlboard/src/ctrlboard_hw/hardware_button.py
index 43268f68..d8e79226 100644
--- a/python/ctrlboard/src/ctrlboard_hw/hardware_button.py
+++ b/python/ctrlboard/src/ctrlboard_hw/hardware_button.py
@@ -11,6 +11,7 @@ class HardwareButton:
         self.state = True
         self.state_interrupt = True
         self.name = "n/a"
+        self.last_press = None
 
     def read(self):
         """Reads the configured port of the i2c multiplexer"""