## What Does It Do? **WebJack is a wired, bidirectional data link between the Arduino Uno and your phone, established via headphone jack.** It uses two distinct frequencies for a modem-like serial transmission of data. WebJacks runs in the browser and its goal is to provide a way to read sensors without the burden to install native applications. Look for recent updates on Public Lab [here](http://publiclab.org/tag/webjack).  ## Activities This is a list of community-generated guides for specific applications and the development of WebJack. These [activities can be categorized](https://publiclab.org/wiki/activity-categories), and some may be more reproduced -- or reproducible -- than others. Try them out to build your skills, and help improve them by leaving comments. Together, we can repeat and refine the activities into experiments. ### Activity grid [activities:webjack] **** ## Frequently Asked Questions Ask a question about WebJack [notes:question:webjack] **** [](//i.publiclab.org/system/images/photos/000/017/089/original/IMG_0138_web.JPG) WebJack is an open source client-side JavaScript library that acts as audio modem. It is built for use with [SoftModem](https://github.com/arms22/SoftModem), the Arduino-side code. For example, with WebJack you can transmit: * data as text * binary data * Firmata RPC messages *** ## Challenges We're working to refine and improve WebJack on a number of fronts; here, take a look at the leading challenges we're hoping to solve, and post your own. Be sure to add: * constraints: expense, complexity * goals: performance, use cases [questions:webjack-challenge] **** ## Build a data link with WebJack Instructions on the circuit and software needed for WebJack can be found here: https://publiclab.org/notes/rmeister/07-18-2016/webjack-testers-needed ### Demo WebJack applications - [Using Firmata with WebJack as transport](https://publiclab.github.io/webjack-firmata/example): - [WebJack demo website](https://publiclab.github.io/webjack/examples) ###Notes: - For more information about WebJack, post a question to the "dev" mailing list [here](https://groups.google.com/group/plots-dev)) (also listed in the left sidebar) - The github repo of WebJack is [here](https://github.com/publiclab/webjack) ...
| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| rmeister | "@warren this is the tutorial for testing without Arduino :) Signal looks fine though. Remember to change the frequencies in SoftModem.h " | Read more » | over 8 years ago | |||
| rmeister | "That could work. But you will need an additional adapter for every device with AHJ pinout: https://www.headsetbuddy.com/3-5mm-ctia-to-omtp-smartpho..." | Read more » | over 8 years ago | |||
| warren | "I tried again (after this attempt) and turned down the audio gain, but still didn't receive on the gh-pages demo. It doesn't look blown out: H..." | Read more » | over 8 years ago | |||
| warren | "I'm thinking about how we might add some hints for how to most easily do browser-to-browser over a cable. Just an idea -- what if we used these two..." | Read more » | over 8 years ago | |||
| rmeister | "Leonardo is again a different processor with different names for the timers used in the library. I think we can fix that with some #ifdef's in the ..." | Read more » | over 8 years ago | |||
| warren | "Hmm, the Leonardo also failed to compile with similar errors to the ATTiny -- odd; I wonder if there's something wrong with my setup in general... ..." | Read more » | over 8 years ago | |||
| warren | "I also have a Leonardo I can test this out on, I'll dig it up. " | Read more » | over 8 years ago | |||
| rmeister | "Cool, thanks for your effort! " | Read more » | over 8 years ago | |||
| warren | "Oh, cool! I heard that "dimming" occur when I piped the sound through a small amplifier, but didn't know it was supposed to be that way. Neat. Than..." | Read more » | over 8 years ago | |||
| rmeister | "If the nanite's output is 3V, then the voltage at your phone will be about 3V as well for the first few periods. But after a couple of periods the ..." | Read more » | over 8 years ago | |||
| warren | "Another question... I see that voltage on a 'nanite' arduino clone is ~3v, and I'm wondering; peak to peak line load seems to be around -1.5-1.5v f..." | Read more » | over 8 years ago | |||
| warren | "https://github.com/publiclab/webjack/issues/17 " | Read more » | over 8 years ago | |||
| warren | "Maybe we should create an issue on the WebJack project so as not to make this thread too long. I made some progress (rather crudely) copying over ..." | Read more » | over 8 years ago | |||
| warren | "It looks like SoftModem-for-attiny85 doesn't include this line: https://github.com/rmeister/SoftModem/blob/webjack/SoftModem.cpp#L273-L304 // Bri..." | Read more » | over 8 years ago | |||
| warren | "OK, finally got some feedback, though not sure how helpful; I actually got stuck on installing softmodem itself; error here: https://gist.github.c..." | Read more » | over 8 years ago | |||
| rmeister | " For an (unequally) attenuated signal, the amplitudes for f_low and f_high are uneven. In this case, the amplitude for f_high is very low. Cool, ..." | Read more » | over 8 years ago | |||
| warren | "What are you looking at specifically when you see that the higher frequencies are attenuated? What part of the waveform, can you highlight it? I s..." | Read more » | over 8 years ago | |||
| rmeister | "Oh yes, the signal is still attenuated. Didn't see that on my phone yesterday. " | Read more » | over 8 years ago | |||
| kinasmith | "yeah. no dice...still doesn't work. I'll try it on a different phone when I get home. " | Read more » | over 8 years ago | |||
| rmeister | "Cool, looks good. Thanks for your effort! Maybe try switching the wires to sleeve and ring2. " | Read more » | over 8 years ago | |||
| kinasmith | "Hah. That's flattering, but my background isn't electrical engineering...I just kind of stumbled into it. The circuit is pretty obvious now that I ..." | Read more » | over 8 years ago | |||
| rmeister | "Probably you ment an other circuit, as I see you have a background in electronics engineering :D " | Read more » | over 8 years ago | |||
| rmeister | "It's a voltage divider (so your phone won't be damaged by a too large voltage) and a high-pass filter (removes DC voltage). Would you give it a tr..." | Read more » | over 8 years ago | |||
| kinasmith | "I was using Chrome. Didn't try any others. Just curious, but what is the function of the circuit? " | Read more » | over 8 years ago |