Hardware PWM using lightweight rpi_hardware_pwm library

README.md

@@ -36,7 +36,7 @@ Install the plugin using the Plugin Manager bundled with OctoPrint, you can sear
 
 This plugin support many hardware temperature sensors, led, relays, heater...
 
-Here are detailled instructions on how to setup them.
+Here are detailed instructions on how to setup them.
 
 ### Temperature sensors
 
@@ -136,7 +136,7 @@ If your setup does not have pip install pip:
 Install the required library:
 `sudo pip install rpi_ws281x`
 
-rpi_ws281x really needs sudo, and you need to setup up so your rpi does not ask for a password when runing a python script, so run:
+rpi_ws281x really needs sudo, and you need to setup up so your rpi does not ask for a password when running a python script, so run:
 
 `sudo visudo`
 
@@ -148,6 +148,20 @@ Also backlist the audio kernel:
 
 add the `blacklist snd_bcm2835` to the end of the file.
 
+### Hardware PWM
+
+Hardware PWM is required in order to drive higher frequency signals, such as the 25000 Hz needed by Noctua PWM fans. The rpi-hardware-pwm module is used as a lightweight alternative to pigpio. Install the required library: `sudo pip install rpi-hardware-pwm`
+
+Enable PWM0 (GPIO 18) by adding the following line to `/boot/config.txt`
+
+```
+dtoverlay=pwm
+```
+
+If you wish to use both PWM0 and PWM1 then use `dtoverlay=pwm-2chan` instead. If you wish to use the alternate PWM pin numbers, then read the [rpi-hardware-pwm module readme](https://github.com/Pioreactor/rpi_hardware_pwm) for how this can be configured.
+
+After editing `boot/config.text` reboot your Raspberry Pi.
+
 ### GPIO
 
 This release uses RPi.GPIO to control IO of raspberry pi, it should install and work automatically. If it doesn't please update your octoprint with the latest release of octopi.
@@ -186,8 +200,8 @@ Outputs are meant to control THINGS (temperature, lights, locker, extra enclosur
 Outputs can be set to the following types:
 
 * Regular GPIO
-* PWM GPIO
-* Neopixel Control via Microcontroler
+* PWM GPIO (Software or Hardware controlled PWM)
+* Neopixel Control via Microcontroller
 * Neopixel Control directly from raspberry pi
 * Temperature and Humidity Control
 * Temperature Alarm

octoprint_enclosure/__init__.py

@@ -55,6 +55,17 @@ def CheckInputActiveLow(Input_Pull_Resistor):
     else:
         return False
 
+#Function that returns the hardware PWM channel or raises ValueError otherwise
+def Pwm_Channel(pin):
+    pwm0_pins = [12, 18]
+    pwm1_pins = [13, 19]
+    if pin in pwm0_pins:
+        return 0
+    elif pin in pwm1_pins:
+        return 1
+    else:
+        raise ValueError("Not a Hardware PWM pin")
+
 class EnclosurePlugin(octoprint.plugin.StartupPlugin, octoprint.plugin.TemplatePlugin, octoprint.plugin.SettingsPlugin,
                       octoprint.plugin.AssetPlugin, octoprint.plugin.BlueprintPlugin,
                       octoprint.plugin.EventHandlerPlugin):
@@ -167,16 +178,16 @@ def on_after_startup(self):
         self.print_complete = False
 
     def get_settings_version(self):
-        return 10
+        return 11
 
     def on_settings_migrate(self, target, current=None):
         self._logger.warn("######### current settings version %s target settings version %s #########", current, target)
         self._logger.info("#########        Current settings        #########")
         self._logger.info("rpi_outputs: %s", self.rpi_outputs)
         self._logger.info("rpi_inputs: %s", self.rpi_inputs)
         self._logger.info("#########        End Current Settings        #########")
-        if current >= 4 and target == 10:
-            self._logger.warn("######### migrating settings to v10 #########")
+        if current >= 4 and target == 11:
+            self._logger.warn("######### migrating settings to v11 #########")
             old_outputs = self._settings.get(["rpi_outputs"])
             old_inputs = self._settings.get(["rpi_inputs"])
             for rpi_output in old_outputs:
@@ -199,7 +210,9 @@ def on_settings_migrate(self, target, current=None):
                 if 'gpio_i2c_register_status' not in rpi_output:
                     rpi_output['gpio_i2c_register_status'] = 1
                 if 'shutdown_on_error' not in rpi_output:
-                        rpi_output['shutdown_on_error'] = False
+                    rpi_output['shutdown_on_error'] = False
+                if 'hw_pwm' not in rpi_output:
+                        rpi_output['hw_pwm'] = False
             self._settings.set(["rpi_outputs"], old_outputs)
 
             old_inputs = self._settings.get(["rpi_inputs"])
@@ -1546,15 +1559,27 @@ def configure_gpio(self):
                     GPIO.setup(pin, GPIO.OUT, initial=initial_value)
             for gpio_out_pwm in list(filter(lambda item: item['output_type'] == 'pwm', self.rpi_outputs)):
                 pin = self.to_int(gpio_out_pwm['gpio_pin'])
-                self._logger.info("Setting GPIO pin %s as PWM", pin)
+                pwm_freqency = self.to_int(gpio_out_pwm["pwm_frequency"])
                 for pwm in (pwm_dict for pwm_dict in self.pwm_instances if pin in pwm_dict):
                     self.pwm_instances.remove(pwm)
                 self.clear_channel(pin)
-                GPIO.setup(pin, GPIO.OUT)
-                pwm_instance = GPIO.PWM(pin, self.to_int(gpio_out_pwm['pwm_frequency']))
-                self._logger.info("starting PWM on pin %s", pin)
-                pwm_instance.start(0)
-                self.pwm_instances.append({pin: pwm_instance})
+                try:
+                    if "hw_pwm" in gpio_out_pwm and gpio_out_pwm["hw_pwm"] is True:
+                        from rpi_hardware_pwm import HardwarePWM
+                        pwm_channel_number = Pwm_Channel(pin)  # Raises valueError if not a hardware PWM pin
+                        self._logger.info("starting Hardware PWM on pin %i channel %i at %i Hz", pin, pwm_channel_number, pwm_freqency)
+                        # If RPi dtoverlay has not been configured this will throw rpi_hardware_pwm.HardwarePWMException with information on what to do.
+                        pwm_instance = HardwarePWM(pwm_channel=pwm_channel_number, hz=pwm_freqency)
+                    else:
+                        self._logger.info("starting PWM on pin %s at %i Hz", pin, pwm_freqency)
+                        GPIO.setup(pin, GPIO.OUT)
+                        pwm_instance = GPIO.PWM(pin, pwm_freqency)
+                    pwm_instance.start(0)
+                    self.pwm_instances.append({pin: pwm_instance})
+                except ImportError as error:
+                    self._logger.error("HardwarePWM module not installed. Install using pip install rpi-hardware-pwm")
+                except ValueError as error:
+                    self._logger.error("Invalid Hardware PMW pin. pwm0 is GPIO pin 18 is physical pin 12 and pwm1 is GPIO pin 19 is physical pin 13")
             for gpio_out_neopixel in list(
                     filter(lambda item: item['output_type'] == 'neopixel_direct', self.rpi_outputs)):
                 pin = self.to_int(gpio_out_neopixel['gpio_pin'])

octoprint_enclosure/static/js/enclosure.js

@@ -380,6 +380,7 @@ $(function () {
         gpio_status: ko.observable(false),
         hide_btn_ui: ko.observable(false),
         active_low: ko.observable(true),
+        hw_pwm: ko.observable(false),
         pwm_temperature_linked: ko.observable(false),
         toggle_timer: ko.observable(false),
         toggle_timer_on: ko.observable(0),

octoprint_enclosure/templates/enclosure_settings.jinja2

@@ -110,6 +110,21 @@
     </div>
     <!-- /ko -->
 
+    <!-- ko if: ($data.output_type() == "pwm" ) -->
+    <div class="control-group">
+      <div class="controls">
+        <label class="checkbox">
+          <input type="checkbox" data-bind="checked: hw_pwm"> {{ _('Use Hardware PWM') }}
+        </label>
+        <span class="help-inline">
+            <span class="label label-important">Attention</span> You need to install and configure the rpi-hardware-pwm module to utilise the hardware PWM on the Pi, check
+            the documentation on the plugin 
+            <a href=" https://github.com/vitormhenrique/OctoPrint-Enclosure">github</a> page. Note: Hardware PWM is only available on GPIO 18 (PWM0) and GPIO 19 (PWM1).</span>
+        </span>
+      </div>
+    </div>
+    <!-- /ko -->
+
     <!-- ko if: ($data.output_type() == "pwm" ) -->
     <div class="control-group">
       <div class="controls">