If you need to add user input without using a button, then a capacitive touch interface might be the answer. The AT42QT1011 SparkFun Capacitive Touch Breakout offers a single, momentary capacitive touch button with easy-to-use digital I/O pins.
The AT42QT1011 is a dedicated, single-button capacitive sense chip. The chip handles monitoring a conductive area for touch. As long as a touch (e.g., from a finger) is detected, the AT42QT1011 keeps the output line high. Otherwise, the line is kept low. You just need to provide a power source (1.8V--5V) and ground for the AT42QT1011 to work. Additionally, a PAD pin is available if you would like to create your own external electrode.
Unlike its sibling, the AT42QT1011 does not have an internal time-out, meaning that if you hold your finger to the breakout’s pad for any length of time, it will stay on. The difference between the AT42QT1010 and the AT42QT1011 is small but may be a game changer depending on your project’s uses.
This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.
Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.
Skill Level: Competent - The toolchain for programming is a bit more complex and will examples may not be explicitly provided for you. You will be required to have a fundamental knowledge of programming and be required to provide your own code. You may need to modify existing libraries or code to work with your specific hardware. Sensor and hardware interfaces will be SPI or I2C.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
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Based on 6 ratings:
The AT42QT1011 worked right out of the box hooking up +5 volts and ground. Bringing the finger close to the button triggered the LED on as expected. My application employs a PIC microcontroller programmed in assembly language. Most of the time the PIC stayed triggered while the finger was held on the button. Once in a while it would drop out. I investigated the output of the breakout with an oscilloscope and found periodically a downward spike lasting about 16 microseconds. In looking at the datasheet I discovered that device has a HeartBeat “health” indicator superimposed on the its output. This puts the output into a three-state mode for 15 microseconds periodically. The breakout circuit must pull this line down to +0.6 volts during the three-state mode. This will not cause any problems in most applications and once we know about it we can work around it if we have to. It was an interesting investigation and it helped me to learn more about the chip. I have oscilloscope pictures if interested.
I needed something to replace a push button switch on my new project. This item exceeded my expectations, because it can detect a light finger tap through a plastic case, which simplifies my design. Thanks to the small size, it fits inside the existing case, and the low cost makes it possible to replicate the project and sell it at a profit.
This capacitive touch breakout is awesome. Dead-simple to use, looks amazing and with the ability to work through thin layers of plastics, the perfect addition to your next project. You're going to want more than one. Do yourself a favor and buy at least 3 of these guys.
works as advertised, well made, great instructions
This sensor is giving me many problems, many because of its irregularity in the signal. It constantly shows phantom signals, which makes it almost useless. I do not understand how they can sell a button so badly designed or at least provide a solution!. Would you be interested in oscilloscope readings, could you share them here with a link? Thank you!
Hello and thank you for your review. We have found these boards to be very reliable and it's possible that something in your setup or the board itself may have an issue. Please contact our support team for assistance with your troubles and they will be happy to help you.
Have been using this sensor to detect the presence of an occupant sitting in a chair. The sensor is placed beneath the seat so is invisible to the occupant. It has been working reliably as specified. I first purchased a similar sensor from Adafruit... unfortunately this was the AT42QT1010 (not the 1011 like this one). The 1010 is designed to reset its zero after ~60 seconds of continuous "presence". This doesn't work for my application, as an occupant may remain for more than 60s. This product (the AT42QT1011) states in the datasheet that it doesn't have this feature, and indeed, it has been working perfectly for the last few weeks in my application.