HTML5 web app PWM audio generator for Servo Motors

Volume:
Ch1 Degrees: -90 +90
Ch2 Degrees: -90 +90

Connecting a PC or SmartPhone audio headphone jack to a pair of servos requires no more than an 0.1uF decoupling capacitor in line from each stereo channel to the servo PWM input.
http://www.gluemotor.com/how-to-make

Note: This circuit will only work with devices that have a very loud audio output. In most cases, a simple transistor amplifier will be required. If you can help with the design of such an amp using commonly available parts, please contact us.

ToDo:

• Develop easily made open source hardware which will work with any audio output and servo.
• Allow wavforms to be saved at the current volume and degree to support browsers without <audio> tag support.
• Support two servos with right / left channel stereo generation.
• Setup a pull down for common sample rates.
• Done: Adjust samplesPerCycle to a even divisor of bufferLength to remove the 1 second tick
• Done: Added a visualization so you can see what the wave form is supposed to look like

In the short time this page has been up, the Web Audio API has already changed and broken it. First by replacing context.createGainNode(); with context.createGain(); and by replacing context.createBufferSource().noteOn(0); with context.createBufferSource().start(0);.

Based on this level of instability, and the fact that this method is not compatible with older SmartPhones and browsers, it may be better to focus on other methods of communicating with the world, such as the I2C via GIF idea.

• https://hackaday.io/project/4926-cheepit-sparrow-dev-boards-for-smartphones Using browser generated audio to program a microcontroller.