We’ve all been there: after assessing a problem and thinking about a solution, we immediately rush to pursue the first that comes to mind, only to later find that there was a vastly simpler alternative. Thankfully, developing an obscure solution, though sometimes frustrating at the time, does tend to make a good Hackaday post. This time it was [David Wehr] and AudioSerial: a simple way of outputting raw serial data over the audio port of an Android phone. Though [David] could have easily used USB OTG for this project, many microcontrollers don’t have the USB-to-TTL capabilities of his Arduino – so this wasn’t entirely in vain.

At first, it seemed like a simple task: any respectable phone’s DAC should have a sample rate of at least 44.1kHz. [David] used Oboe, a high performance C++ library for Android audio apps, to create the required waveform. The 8-bit data chunks he sent can only make up 256 unique messages, so he pre-generated them. However, the DAC tried to be clever and do some interpolation with the signal – great for audio, not so much for digital waveforms. You can see the warped signal in blue compared to what it should be in orange. To fix this, an op-amp comparator was used to clean up the signal, as well as boosting it to the required voltage.

Prefer your Arduino connections wireless? Check out this smartphone-controlled periodic table of elements, or this wireless robotic hand.

What’s a hacker to do to profess his love for his dearest beloved? [Nitesh Kadyan] built his lady-love this awesome LED pendant – the LED BLE Hearty Necklace Badge.

The hardware is pretty vanilla by today’s hacker standards. An ATMega328p  does most of the heavy lifting. An HM-11 BLE module provides connection to an Android mobile app. Two 74HC595 shift registers drive 16 columns of red LEDs and a ULN2803 sinks current from the 8 rows. The power section consists of a charger for the 320mAh LiPo and an LDO for the BLE module. All the parts are SMD with the passives mostly being 0603, including the 128 LEDs.

[Nitesh] didn’t get a stencil made for his first batch of boards, so all the parts were painstakingly soldered manually and not in a reflow oven. And on his first board, he ended up soldering all of the LED’s the wrong way around. Kudos to him for his doggedness and patience.

The Arduino code on the ATmega is also quite straightforward. All characters are stored as eight bytes each in program memory and occupy 8×8 pixels on the matrix. The bytes to be displayed are stored in a buffer and the columns are left shifted fast enough for the marquee text effect. The Android app is built by modifying a demo BLE app provided by Google. The firmware, Android app, and the KiCAD design files are all hosted on his Github repository.

[Nitesh] is now building a larger batch of these badges to bring them to hillhacks – the annual hacker-con for making and hacking in the Himalayas. Scheduled for later this month, you’ll have to sign up on the mailing list for details and if you’d like to snag one of these badges. To make it more interesting, [Nitesh] has added two games to the code – Tetris and Snakes. Hopefully, this will spur others to create more games for the badge, such as Pong.

Use JJ Robots' kit and your Android phone to build an air hockey partner who's always game.

Read more on MAKE

The post Assemble a Robot Opponent for Air Hockey appeared first on Make: DIY Projects and Ideas for Makers.

I would like to add wifi control to my robot.  Right now it uses an Arduino Mega2650 to run the main control program.  I'd like to add to this contol inputs from an Android smartphone app over Wifi.  What do you recommend to do this?  

I would like to add wifi control to my robot.  Right now it uses an Arduino Mega2650 to run the main control program.  I'd like to add to this contol inputs from an Android smartphone app over Wifi.  What do you recommend to do this?  

I would like to add wifi control to my robot.  Right now it uses an Arduino Mega2650 to run the main control program.  I'd like to add to this contol inputs from an Android smartphone app over Wifi.  What do you recommend to do this?  

I would like to add wifi control to my robot.  Right now it uses an Arduino Mega2650 to run the main control program.  I'd like to add to this contol inputs from an Android smartphone app over Wifi.  What do you recommend to do this?  

Unlike many cars today, Aykut Celik’s 2014 Volkswagen Polo didn’t have Bluetooth connectivity or an elaborate touchscreen navigation system. So, the Maker decided to take matters into his own hands and swapped out his “useless” radio for a Samsung tablet, putting Google Maps, Spotify and other apps right in his vehicle’s dashboard.

In order to accomplish this, Celik needed an amplifier (to replace the one attached to the prior radio), a CAN bus shield from Seeed (so he could use the steering wheel’s volume buttons), a Bluetooth module, and an Arduino Mega 2560 (for parsing data and sending it over to the Android device).

A CAN-BUS shield is necessary to be able to read CAN-BUS commands from the CAN bus line… I used this shield for detecting wheel button commands like volume up, mute and volume down. Behind the car radio there are two CAN bus cables. One of them is CAN bus – HIGH and the other is CAN bus – LOW. These cables must be connected to green sockets on the shield.

Using the SeeedCAN bus shield, you can sniff you car’s CAN bus data.

The info which is gathered from CAN bus is transferred to the Android tablet via Bluetooth. There is a little app which is responsible, for example, reducing volume whenever the wheel volume button is clicked. And a menu activity to open other apps.

You can watch the elaborate project below, and read more about it on Celik’s blog. The Maker has also made the software and other information available on GitHub.

Are you (or your kid) curious about the world around you? Google wants to help. It just launched Science Journal, an Android app that helps you perform (and comment on) simple science experiments. The app can record light, motion and sound levels using only your phone's sensors, letting you study everything from a light bulb's brightness to the acceleration in a jump. It's easy to kick things up a notch, though. You can connect Arduino-powered sensors, and Google is partnering with Exploratorium to offer starter kits to help budding scientists. Science Journal is free, so there's no harm in giving it a try -- even if you're a full-fledged adult, you might learn something.

Via: Android Police

Source: Google Play, Google for Education

Are you (or your kid) curious about the world around you? Google wants to help. It just launched Science Journal, an Android app that helps you perform (and comment on) simple science experiments. The app can record light, motion and sound levels using only your phone's sensors, letting you study everything from a light bulb's brightness to the acceleration in a jump. It's easy to kick things up a notch, though. You can connect Arduino-powered sensors, and Google is partnering with Exploratorium to offer starter kits to help budding scientists. Science Journal is free, so there's no harm in giving it a try -- even if you're a full-fledged adult, you might learn something.

Via: Android Police

Source: Google Play, Google for Education