Example - managing fan of Raspberry Pi enclosure

Examples/Microsoft.PowerShell.IoT.Fan/Microsoft.PowerShell.IoT.Fan.psd1

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+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+@{
+    GUID="0432ee36-7e87-4a21-814f-8feb17974647"
+    Author="Microsoft Corporation"
+    CompanyName="Microsoft Corporation"
+    Copyright="© Microsoft Corporation. All rights reserved."
+    Description='PowerShell module for controling a fan over GPIO.'
+    ModuleVersion="0.1.0"
+    FunctionsToExport = @('Enable-Fan','Disable-Fan')
+    CmdletsToExport = @()
+    AliasesToExport = @()
+    RootModule = 'Microsoft.PowerShell.IoT.Fan.psm1'
+    NestedModules=@('Microsoft.PowerShell.IoT')
+    HelpInfoURI = 'https://github.com/PowerShell/PowerShell-IoT'
+    # Private data to pass to the module specified in RootModule/ModuleToProcess. This may also contain a PSData hashtable with additional module metadata used by PowerShell.
+    PrivateData = @{
+        PSData = @{
+            # Tags applied to this module. These help with module discovery in online galleries.
+            Tags = 'IoT','RaspberryPi','Raspbian'
+
+            # A URL to the license for this module.
+            LicenseUri = 'https://github.com/PowerShell/PowerShell-IoT/blob/master/LICENSE.txt'
+
+            # A URL to the main website for this project.
+            ProjectUri = 'https://github.com/PowerShell/PowerShell-IoT'
+        }
+    }
+}

Examples/Microsoft.PowerShell.IoT.Fan/Microsoft.PowerShell.IoT.Fan.psm1

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+function Enable-Fan
+{
+    [CmdletBinding()]
+    param
+    (
+        [Parameter(Mandatory=$true, Position=0)]
+        [ValidateNotNullOrEmpty()]
+        [int] $Pin
+    )
+
+    Set-GpioPin -Id $Pin -Value High
+}
+
+function Disable-Fan
+{
+    [CmdletBinding()]
+    param
+    (
+        [Parameter(Mandatory=$true, Position=0)]
+        [ValidateNotNullOrEmpty()]
+        [int] $Pin
+    )
+
+    Set-GpioPin -Id $Pin -Value Low
+}

Examples/Microsoft.PowerShell.IoT.Fan/README.md

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+# Example module Microsoft.PowerShell.IoT.Fan
+
+This PowerShell module is for turning on/off a fan on Raspberry Pi 4 case enclosure.
+This showcases GPIO functionality of [the Microsoft.PowerShell.IoT module](../../README.md).
+
+## Hardware setup
+
+[This Raspberry Pi 4 case enclosure](https://www.amazon.com/gp/product/B07XTRK8D4) comes with a 5V fan that can be connected to Raspberry Pi 5V and GND pins.
+This fan is nice but a little noisy so we can use this example module to turn it off when the CPU temperature is relatively low.
+An [IRLB8721 transistor](https://www.adafruit.com/product/355) can be used to switch power to the fan based on GPIO line of Raspberry Pi.
+
+## Wiring
+
+Insert IRLB8721 transistor into the break of the negative wire of the fan.
+Connect transistor gate to GPIO 17 (BCM schema) on Raspberry Pi.
+
+![Mossfet1](https://user-images.githubusercontent.com/11860095/79925701-d6a85580-83ef-11ea-894d-93507507df5e.jpg)
+![Mossfet2](https://user-images.githubusercontent.com/11860095/79925725-e6c03500-83ef-11ea-9abd-7dd39be69bd1.jpg)
+
+## Software setup
+
+### Install PowerShell Core on Raspberry Pi
+
+Installation instructions can be found [here](https://github.com/PowerShell/PowerShell/tree/master/docs/installation/linux.md#raspbian).
+
+### Start Powershell and install modules
+
+```powershell
+pwsh
+
+Install-Module -Name Microsoft.PowerShell.IoT
+
+git clone https://github.com/PowerShell/PowerShell-IoT.git
+```
+
+### Usage
+
+```powershell
+# Start monitoring CPU temperature and turn on the fan when it reaches 71 degrees; turn fan off when CPU temperature drops below 55 degrees
+pwsh ./PowerShell-IoT/Examples/Microsoft.PowerShell.IoT.Fan/SmartFan.ps1 -Pin 17 -OnTemperature 71 -OffTemperature 55 -TemperatureScale Celsius
+VERBOSE: 1:36:05 PM: CPU temperature  =  71.575 C | 160.835 F
+VERBOSE: Starting fan...
+VERBOSE: 1:36:10 PM: CPU temperature  =  70.601 C | 159.0818 F
+VERBOSE: 1:36:16 PM: CPU temperature  =  70.114 C | 158.2052 F
+VERBOSE: 1:36:21 PM: CPU temperature  =  68.653 C | 155.5754 F
+#...
+VERBOSE: 1:39:01 PM: CPU temperature  =  55.504 C | 131.9072 F
+VERBOSE: 1:39:06 PM: CPU temperature  =  55.504 C | 131.9072 F
+VERBOSE: 1:39:11 PM: CPU temperature  =  54.043 C | 129.2774 F
+VERBOSE: Stopping fan...
+VERBOSE: 1:39:17 PM: CPU temperature  =  55.991 C | 132.7838 F
+#...
+```
+
+This produces following CPU temperature graph:
+![CPU-Temp-graph](https://user-images.githubusercontent.com/11860095/79926138-fbe99380-83f0-11ea-8705-b1336fc7bd7d.png)

Examples/Microsoft.PowerShell.IoT.Fan/SmartFan.ps1

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+param
+(
+    [int] $Pin = 17,
+    [int] $OnTemperature = 70,
+    [int] $OffTemperature = 50,
+    [ValidateSet("Fahrenheit","Celsius")]
+    [string]$TemperatureScale = "Celsius",
+    [int] $PollPeriodSeconds = 5
+)
+
+Import-Module $PSScriptRoot/Microsoft.PowerShell.IoT.Fan.psd1
+
+$OnTemperatureC = $OnTemperature
+$OffTemperatureC = $OffTemperature
+if ($TemperatureScale -eq "Fahrenheit")
+{
+    $OnTemperatureC = ($OnTemperature - 32) * 5 / 9
+    $OffTemperatureC = ($OffTemperature - 32) * 5 / 9
+}
+
+while($true)
+{
+    $CpuTemperatureC = (Get-Content /sys/class/thermal/thermal_zone0/temp) / 1000
+    $CpuTemperatureF = ($CpuTemperatureC * 9 / 5) + 32
+
+    (Get-Date).ToString() + ": CPU temperature  =  $CpuTemperatureC C | $CpuTemperatureF F" | Write-Verbose
+
+    if ($CpuTemperatureC -gt $OnTemperatureC)
+    {
+        "Starting fan..." | Write-Verbose
+        Enable-Fan -Pin $Pin
+    }
+    elseif ($CpuTemperatureC -lt $OffTemperatureC)
+    {
+        "Stopping fan..." | Write-Verbose
+        Disable-Fan -Pin $Pin
+    }
+
+    Start-Sleep -Seconds $PollPeriodSeconds
+}