Tutorial: Using Basic Resistor Sensor Reading on Raspberry Pi – Adafruit Learning System #piday #raspberrypi @Raspberry_Pi

Shade

1324

Tutorial: Using Basic Resistor Sensor Reading on Raspberry Pi @ Adafruit Learning System.

We’ve already covered how to use an Analog-to-Digital Converter chip with a Pi. These chips are the best way to read analog voltages from the Pi. However, there’s a way to read many sensors without an ADC! By measuring the sensor as a resistor that is used to ‘fill up’ a capacitor, we can count how long it takes. It’s not nearly as precise as an ADC and its a little flakey (since it depends on the Pi timing itself which can vary based on how ‘busy’ the computer is)

The way we do this is by taking advantage of a basic electronic property of resistors and capacitors. It turns out that if you take a capacitor that is initially storing no voltage, and then connect it to power (like 3.3V) through a resistor, it will charge up to the power voltage slowly. The bigger the resistor, the slower it is.

This technique only works with sensors that act like resistors. however, there are quite a few fun sensors that act this way: photocells, thermistors (temperature sensors), flex sensors, force-sensitive resistors, and many more.

It cannot be used with sensors that have a pure analog output like IR distance sensors or analog accelerometers.

Learn more…

Friday is PiDay here at Adafruit, be sure to check out our posts, tutorials and new Raspberry Pi related products.

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 35,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — How (some) chips get made

Wearables — Need a lot of power for your project? Read on!

Electronics — Storage Safety 101

Python for Microcontrollers — Python on Microcontrollers Newsletter: 10K Subscribers, Picos Made in Africa and more!! #CircuitPython @micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Turtle Eggs, Pool Monitors, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/30/22 Featuring Adafruit Feather RP2040! (Video)

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !

No Comments

No comments yet.

Sorry, the comment form is closed at this time.

Filed under: Raspberry Pi — by adafruit

Comments Off on Tutorial: Using Basic Resistor Sensor Reading on Raspberry Pi – Adafruit Learning System #piday #raspberrypi @Raspberry_Pi