Chromecast Audio Adapter

I listen to music on Chromecast all the time, and it's awesome, but sometimes I like to listen to music on my stereo, which has no HDMI input. For the past year I searched for a cost effective way to adapt the wonderfully cheap $25 Chromecast to audio only hardware.

I found a $15 adapter that works great, but it required a little hacking.

Chromecast audio adapter

Yes, that's a resistor sticking out of it. Here's a step-by-step.

  1. Buy a LinkS hdmi to vga adapter. They're about $15 on Amazon.
  2. Plug in your Chromecast and give it a spin. If yours is like mine, no audio came out, which is really sad.
  3. Find a 75 ohm resistor, or a more common 82 ohm resistor. Create a VGA dummy plug. You might need to wire up as many as 3 resisors, but mine works fine with only one resistor connecting pins 2 and 7.
  4. Plug it in to USB power, and then plug in a 3.5mm audio cable. Give it another test.
  5. Is it buzzing? It's probably a ground fault. Make sure that the stereo and Chromecast's power supply have a common ground. In other words, try plugging them into the same power strip.

Check APK Permissions with aapt

Side loading is fun, it gives us a chance to help developers test their Glassware. You can install an apk like so:

$ adb install cat-generator.apk

That sure is easy. But, this is a developer thing. Like many developer things, it assumes you know what you're doing, and that you trust the source of your software. It bypasses some security safeguards. This is why it's really important to understand what you're installing.

Before you sideload, protect yourself! There's a tool in your Android SDK: the Android Asset Packaging Tool, also called aapt. You can use it to inspect apk files.

Follow these steps:

  1. Find aapt. It lives in the <android-sdk>/build-tools/<version number>/ directory. I use it enough that I add it to my system path.
  2. Dump the permissions on the apk you're curious about.

    $ aapt dump permissions ./cat-generator.apk
    uses-permission: android.permission.INTERNET

  3. Check the permissions against the list in the Android reference docs to learn what they do.

  4. If you see anything unexpected, ask the developer. They should be happy to explain the permissions they request.

Make a 3.5mm Audio Adapter for Google Glass

Circuit diagram of a 3.5mm audio adapter for Google Glass

You've just built a really cool Glassware. People love it, and someone has asked you to present it to a large audience. One problem: the coolest part about your app is the sound. You can already present video over adb with tools like Android Screen Monitor, but they do not share audio.

To make matters worse, there's no standard for delivering audio over USB. Every manufacturer has its own of delivering audio from a microUSB port, so no off-the-shelf adapter is going to do the trick.

Never fear! There's a solution. You can make one! It involves a little solder and a resistor, but it's easy, I swear.


  • A headset adapter that adapts microUSB to 3.5mm audio - I used this one from Amazon.
  • A 500kΩ resistor - exactly 500kΩ might be hard to find, so just get as close as you can. I used a 499kΩ±5% that worked great.
  • A soldering iron, some solder, and some solder wick
  • Helping hands make it a lot easier


  1. Open up the headset adapter and take a look around. If you ordered the one linked above, you'll find pins 4 and 5 connected by a solder bridge. If you have a different one, you may find a something else like a resistor or a small circuit board.
  2. Clean it up. Remove the solder bridge. If there's other stuff in there, disassemble it. This is where the solder wick comes in handy.
  3. Use the 500kΩ resistor to connect pins 4 and 5.
  4. If necessary, wire up D+ and D- to the audio channels, and connect the two grounds. This is already done on the adapter I linked above.
  5. Get up on stage, plug in, and share awesome tunes and beats with your audience.

Source: This content is adapter from an answer I posted to Stack Overflow that was closed because it involved too much soldering.

Mid-career Crisis: Exploring Challenges and Opportunities


  • Adriana Compagnoni (Stevens Institute of Technology)
  • Susan Staffin-Metz (Women in Engineering Proactive Network)
  • Elaine Weyuker (AT&T Labs)

The Mid-career crisis

Women in technical fields face challenges that their male counterparts do not. Women are expected to balance home life, children raising, growing their careers and often supporting ailing family members. Women are more likely to experience stress related illness. In attempting to satisfy all of these needs in their lives, they often loose touch with their personal needs and end up having a reduced quality of life.

In this interactive session, panelists and attendees shared their personal accounts of their mid-career crisises, the challenges that they faced, and how they overcame them to find success. Here's a solution oriented summary of the topics discussed.

You cannot do everything

Society pressures us to juggle many things. Sometimes this is not possible. If you attempt to juggle everything that life throws at you, you may struggle. Decide what you would like to focus on, and be awesome at it. If you'd like to focus on building a successful career, do not be afraid to hire a maid or nanny. Just because you are not doing everything yourself does not mean you're a failure. You are doing yourself and those around you a service by making sure that you stay healthy.

Mentors are important

Sometimes we are the only woman on our team. Sometimes it's hard to find people near you for advice. One powerful way to avoid feeling alone is to find a mentor. Seek out and make use of a mentor. Mentors can span your entire career. They provide perspective on your situations that you may not find elsewhere.

If you've having trouble finding a mentor, leverage the resources around you such as the Systers program.

Live to work or work to live?

Some people live to work. Other people work to live. Do not assume that you have to follow the path laid out in front of you to be successful. It's OK to not work late every night. Even if you have other priorities in your life, your contribution is still valuable.

Vivek Wadhwa - Where The Next Billion Dollar Opportunities Lie

In this session Vivek attempted to dispel the myth that innovation has peaked. He did this by presenting numerous compelling examples of recent exciting advances in technology and describing several predicted breakthroughs. Throughout this discussion he challenged attendees to focus on saving the world instead of focusing on making a quick buck by turning out the next social media startup. He further postulated that the next billion dollar idea was not in social media, which he characterized as frivolous.

Here are a few of his examples of both where technology seems to have plateaued and, conversely, where it is accelerating.

Some examples where technology has plateaued

  • We flew to this conference in aircraft that are likely 50 years old.
  • In the last 2 generations nuclear power was invented and the automobile came into common use. But these technologies we interact with daily seem almost frozen now.
  • The last big business boom was fueled by the social media creations of college drop-outs.

A few examples of upcoming awesome

Things look bleak. We're on the the edge of peak oil, scarcity of fresh water looms in front of us, and climate change is beginning to have very real impacts on humanity. All this time, though, we've lost sight of the progress we're making in strides.

  • Smart phones put the world's information in your pocket. You, with your smart phone, have better access to developing world events than President Regan did 30 years ago. You also have better access to medical information that physicians of the 80s.
  • Solar power is approaching financial parity with traditional energy generation techniques. Solar cells are already starting to pop up all over India to replace diesel generators, and this will only get better.
  • The first sequencing of the human genome took 13 years and cost $3 billion. Today you can have it done for $3000. Soon it may be as cheap as $100.
  • The smart phone in your pocket has more computing power than the entire world did in 1970. It also has more sophisticated sensors for acceleration and orientation than multimillion dollar projects of yesteryear.

Challenges in front of us

All of these great advances are happening, even if we don't recognize their magnitude. Based on how fast things are advancing on these fronts, immagine what impact you can have on making fresh water available to the 2.4 billion people who currently lack it. Imagine how effective you could be at helping educate the world.

Some editorializing

Vivek's presentation was charismatic and inspiring. I felt challenged to save the world, and making an impact seemed quite possible. But, pretty quickly this feeling passed. He presented scores of examples of advancing technology and promised future breakthroughs, but one thing history has taught us is that we cannot predict when a field of development will hit unforeseen challenges and plateau. For example, solar cells may continue to advance rapidly, but our ability to store and load balance this energy may greatly reduce its impact. We never know when there's a road block around the corner.

Additionally, in an attempt to tune his discussion to and audience dominated by women, some of the claims he made started to edge into oppositional sexism. For example, he made the blanket statement that the audience is better suited to save the world because unlike men, women are altruistic and not focused on building financial wealth. As a result, we will not be distracted by starting a frivolous social media startup. These kinds of assumptions left a bad taste in my mouth. Just because we're women does not mean that we do not share some of the same drives as our male counterparts.

In spite of these issues, this session did challenge me to explore how I can better use my skills to positively impact humanity.