menu: initial support for analog buttons (#977)

Signed-off-by: Janar Sööt <janar.soot@gmail.com>

klippy/extras/buttons.py

@@ -7,6 +7,10 @@ import logging
 
 QUERY_TIME = .002
 RETRANSMIT_COUNT = 50
+ADC_REPORT_TIME = 0.015
+ADC_DEBOUNCE_TIME = 0.025
+ADC_SAMPLE_TIME = 0.001
+ADC_SAMPLE_COUNT = 6
 
 # Rotary encoder handler https://github.com/brianlow/Rotary
 # Copyright 2011 Ben Buxton (bb@cactii.net).
@@ -112,6 +116,79 @@ class MCU_buttons:
         self.last_button = button
 
 
+class MCU_ADC_buttons:
+    def __init__(self, printer, pin, pullup, debug=False):
+        self.reactor = printer.get_reactor()
+        self.buttons = []
+        self.last_button = None
+        self.last_pressed = None
+        self.last_debouncetime = 0
+        self.pullup = pullup
+        self.debug = debug
+        self.pin = pin
+        self.min_value = self.max_value = None
+        ppins = printer.lookup_object('pins')
+        self.mcu_adc = ppins.setup_pin('adc', self.pin)
+        self.mcu_adc.setup_minmax(ADC_SAMPLE_TIME, ADC_SAMPLE_COUNT)
+        self.mcu_adc.setup_adc_callback(ADC_REPORT_TIME, self.adc_callback)
+
+    def setup_button(self, min_value, max_value, callback):
+        if self.min_value is None:
+            self.min_value = min_value
+        else:
+            self.min_value = min(self.min_value, min_value)
+
+        if self.max_value is None:
+            self.max_value = max_value
+        else:
+            self.max_value = max(self.max_value, max_value)
+
+        self.buttons.append((min_value, max_value, callback))
+
+    def adc_callback(self, read_time, read_value):
+        adc = max(.00001, min(.99999, read_value))
+        r = self.pullup * adc / (1.0 - adc)
+        self.reactor.register_async_callback(
+            (lambda e, s=self, v=r: s.handle_button(e, v)))
+
+    def get_button(self, value):
+        if (self.min_value is not None and self.max_value is not None
+                and self.min_value <= value <= self.max_value):
+            for i, (min_value, max_value, cb) in enumerate(self.buttons):
+                if min_value < value < max_value:
+                    return i
+        return None
+
+    def handle_button(self, eventtime, value):
+        btn = self.get_button(int(value))
+
+        # If the button changed, due to noise or pressing:
+        if btn != self.last_button:
+            # reset the debouncing timer
+            self.last_debouncetime = eventtime
+
+        # button debounce check & new button pressed
+        if ((eventtime - self.last_debouncetime) >= ADC_DEBOUNCE_TIME
+                and self.last_button == btn and self.last_pressed != btn):
+                # release last_pressed
+                if self.last_pressed is not None:
+                    self.call_button(eventtime, self.last_pressed, False)
+                    self.last_pressed = None
+                if btn is not None:
+                    self.call_button(eventtime, btn, True)
+                    self.last_pressed = btn
+
+        self.last_button = btn
+        if self.debug is True:
+            logging.info(
+                "analog pin: %s value: %d" % (self.pin, int(value)))
+
+    def call_button(self, eventtime, button, state):
+        if button < len(self.buttons):
+            minval, maxval, callback = self.buttons[button]
+            callback(eventtime, state)
+
+
 ######################################################################
 # Rotary Encoders
 ######################################################################
@@ -138,6 +215,20 @@ class PrinterButtons:
     def __init__(self, config):
         self.printer = config.get_printer()
         self.mcu_buttons = {}
+        self.adc_buttons = {}
+    def register_adc_button(
+            self, pin, min_val, max_val, pullup, callback, debug=False):
+        adc_buttons = self.adc_buttons.get(pin)
+        if adc_buttons is None:
+            self.adc_buttons[pin] = adc_buttons = MCU_ADC_buttons(
+                self.printer, pin, pullup, debug)
+        adc_buttons.setup_button(min_val, max_val, callback)
+    def register_adc_button_push(
+            self, pin, min_val, max_val, pullup, callback, debug=False):
+        def helper(eventtime, state, callback=callback):
+            if state:
+                callback(eventtime)
+        self.register_adc_button(pin, min_val, max_val, pullup, helper, debug)
     def register_buttons(self, pins, callback):
         # Parse pins
         ppins = self.printer.lookup_object('pins')