## 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 | "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 | |||
| rmeister | "Wow, thanks @kinasmith! Probably this pulses are sort of a presence detection for the microphone? Could be an issue, but most of the signals from ..." | Read more » | over 8 years ago | |||
| kinasmith | "Just tested, didn't work. Phone: Xiaomi MI3C, MIUI 7.1.2 (Android 4.4.4) Component Values: R1, 2.2k; R2, 2.2k, C1, 2µF; R3, 10k. I also tried s..." | Read more » | over 8 years ago | |||
| rmeister | "A friend of mine just tested the demo site of the FSK generator with his iPhone (ios9.3.3). The script does not seem to work anymore :( " | Read more » | over 8 years ago | |||
| dusjagr | "@warren, i am referring to some barriers for connecting to iphones. conceptual barriers that can be circumvented exactly by this method. we use the..." | Read more » | over 8 years ago | |||
| warren | "Wow that's pretty exciting -- safari/iOS would be a huge feature to have. I'm wondering if folks are interested enough in this project to submit a..." | Read more » | over 8 years ago | |||
| rmeister | "Hi @dusjagr, thanks for that hint! Found a Safari compatible version of the FSK generator in your link section. At least sending data to the µC sho..." | Read more » | over 8 years ago | |||
| warren | "Oh, that's so rad, @dusjagr! Why are you keeping it from apple? The WebRTC lib doesn't work on iOS anyhow, since it's not an open platform, but jus..." | Read more » | over 8 years ago | |||
| warren | "Indeed -- maybe it could either just say "not safari or iOS" as https://spectralworkbench.org/capture does, or could specifically return an error a..." | Read more » | over 8 years ago | |||
| dusjagr | "Very nice! we have experimented with the same softModem library on the attiny85 for the same reason of an ultra cheap communication to send data to..." | Read more » | over 8 years ago |