# A CircuitPython BLE Remote Control On/Off Switch ## Overview https://youtu.be/1J2wCvvjqDI I have multiple computers around the house, and sometimes they need to be rebooted remotely. For example, here’s a surveillance camera server that’s located in a locked closet. ![](https://cdn-learn.adafruit.com/assets/assets/000/082/342/medium800/light_CP_Solenoid01.jpg?1570991246) Currently the only way to turn it on is by pressing the illuminated blue push button on the front of the case. Instead of running around the house, to manually reboot the computer, we will use CircuitPython to automate this process! The goal of this tutorial is to build a BLE peripheral that attaches to the front so the server can be turned on remotely from outside the closet. The peripheral will also wirelessly report whether the server is on or off. ![](https://cdn-learn.adafruit.com/assets/assets/000/082/456/medium800/light_CP_Solenoid16.jpg?1571179105) This CircuitPython tutorial demonstrates how to build a battery powered Bluetooth BLE remote control to operate a BLE peripheral hosting a solenoid and a spectrally selective light detector. Two Adafruit Feather nRF52840 Express boards will be used for the BLE client and server. - [Next Page](https://learn.adafruit.com/circuitpython-ble-remote-control-on-off/parts.md) ## Guide Products ### Adafruit Feather nRF52840 Express [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062) The **Adafruit Feather nRF52840 Express** is the new Feather family member with Bluetooth® Low Energy and _native USB support_ featuring the nRF52840!  It's our take on an 'all-in-one' Arduino-compatible + Bluetooth® Low Energy with built-in USB... Out of Stock [Buy Now](https://www.adafruit.com/product/4062) [Related Guides to the Product](https://learn.adafruit.com/products/4062/guides) ### Mini Push-Pull Solenoid - 5V [Mini Push-Pull Solenoid - 5V](https://www.adafruit.com/product/2776) Solenoids are basically electromagnets: they are made of a coil of copper wire with an armature (a slug of metal) in the middle. When the coil is energized, the slug is pulled into the center of the coil. This makes the solenoid able to pull (from one end) or push (from the other). This... In Stock [Buy Now](https://www.adafruit.com/product/2776) [Related Guides to the Product](https://learn.adafruit.com/products/2776/guides) ### N-channel power MOSFET [N-channel power MOSFET](https://www.adafruit.com/product/355) When you need to switch a lot of power, N-channel MOSFETs are best for the job. These FETs can switch over 60A and 30V and are TO-220 packages so they fit nicely into any breadboard or perfboard. Heat sinking is easy with TO-220's, but because of the very low Rds(on) of down to 0.009 ohms... Out of Stock [Buy Now](https://www.adafruit.com/product/355) [Related Guides to the Product](https://learn.adafruit.com/products/355/guides) ### Through-Hole Resistors - 10K ohm 5% 1/4W - Pack of 25 [Through-Hole Resistors - 10K ohm 5% 1/4W - Pack of 25](https://www.adafruit.com/product/2784) ΩMG! You're not going to be able to resist these handy resistor packs! Well, axially, they do all of the resisting for you! This is a **25 Pack of 10K Ω Resistors.** More specifically, they are **carbon film** , through-hole... In Stock [Buy Now](https://www.adafruit.com/product/2784) [Related Guides to the Product](https://learn.adafruit.com/products/2784/guides) ### 1N4001 Diode - 10 pack [1N4001 Diode - 10 pack](https://www.adafruit.com/product/755) This here is a 10 pack of the classic 1N4001 power blocking diode. These are good for reverse polarity protection (put it between your DC power jack and circuitry to avoid a negative-voltage that would zap your delicate electronics), kickback protection (place across your solenoids, relays... In Stock [Buy Now](https://www.adafruit.com/product/755) [Related Guides to the Product](https://learn.adafruit.com/products/755/guides) ### Lithium Ion Polymer Battery Ideal For Feathers - 3.7V 400mAh [Lithium Ion Polymer Battery Ideal For Feathers - 3.7V 400mAh](https://www.adafruit.com/product/3898) Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery has a capacity of **400mAh** for a total of about 1.9 Wh. If you need a larger (or smaller!)... In Stock [Buy Now](https://www.adafruit.com/product/3898) [Related Guides to the Product](https://learn.adafruit.com/products/3898/guides) ### Breadboard-friendly SPDT Slide Switch [Breadboard-friendly SPDT Slide Switch](https://www.adafruit.com/product/805) These nice switches are perfect for use with breadboard and perfboard projects. They have 0.1" spacing and snap in nicely into a solderless breadboard. They're easy to switch no matter what size fingers you have, but not so easy that they'll get flipped by accident. Work great as... In Stock [Buy Now](https://www.adafruit.com/product/805) [Related Guides to the Product](https://learn.adafruit.com/products/805/guides) ## Related Guides - [Introducing the Adafruit nRF52840 Feather](https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather.md) - [Wireless BLE MIDI Robot Xylophone](https://learn.adafruit.com/wireless-ble-midi-robot-xylophone.md) - [reef-pi Guide 5: Light Controller](https://learn.adafruit.com/reef-pi-lighting-controller.md) - [Yoga Pose Chime](https://learn.adafruit.com/yoga-pose-chime.md) - [Flippy Floppy Drive Modification](https://learn.adafruit.com/flippy-floppy-drive-modification.md) - [Thermal Camera with Display](https://learn.adafruit.com/thermal-camera-with-display.md) - [DC, Servo, Stepper Motors and Solenoids with the Pico](https://learn.adafruit.com/use-dc-stepper-servo-motor-solenoid-rp2040-pico.md) - [USB MIDI Host Messenger](https://learn.adafruit.com/usb-midi-host-messenger.md) - [MakeCode Arcade Pixel Art Sprites](https://learn.adafruit.com/makecode-arcade-pixel-art-sprites.md) - [CircuitPython BLE Advertising Beacons](https://learn.adafruit.com/circuitpython-ble-advertising-beacons.md) - [DotStar Fortune Necklace with Bluetooth and Touch](https://learn.adafruit.com/dotstar-fortune-necklace.md) - [BLE HID Keyboard Buttons with CircuitPython](https://learn.adafruit.com/ble-hid-keyboard-buttons-with-circuitpython.md) - [Mini Raspberry Pi Handheld Notebook](https://learn.adafruit.com/mini-raspberry-pi-handheld-notebook-palmtop.md) - [Clue Shot Timer](https://learn.adafruit.com/clue-shot-timer.md) - [Data Logging with Feather and CircuitPython](https://learn.adafruit.com/data-logging-with-feather-and-circuitpython.md) - [Color Sensing Music Player](https://learn.adafruit.com/color-sensing-music-player.md)