Audio hardware: Difference between revisions

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The paper - 'The One Laptop per Child (OLPC) Audio Subystem' by Jaya (Alsa) provides useful information on the audio subsystem. The link is -
The paper - 'The One Laptop per Child (OLPC) Audio Subystem' by Jaya (Alsa) provides useful information on the audio subsystem. The link is -
[www.kgw.tu-berlin.de/~lac2007/papers/lac07_kumar.pdf The OLPC Audio Subsystem]
[http://www.kgw.tu-berlin.de/~lac2007/papers/lac07_kumar.pdf The OLPC Audio Subsystem]


===Microphone Sensor Input===
===Microphone Sensor Input===

Revision as of 02:36, 20 June 2007

  english | 한국어 HowTo [ID# 45052]  +/-  


These are ideas related to both audio input and output. Please review the hardware specification to see what is already included. Some audio-related ideas are also dealt with in the Radio and Broadcast page.

Microphone

A built in Microphone would be usefully if dirt and echo/feedback could be controlled. If you have a microphone and speakers included with these laptops then then if you include a small peice of software they can be used as telephones or walkitalkies -- like an instant message local channel that is as easy to use as a CB radio. If the hardware looked like a radio, the oporator could use it before they learend how to use the computer.

Sound Codec

The [Hardware specification]] page says the Audio Codec is an Analog Devices AD1888, AC97-compatible audio codec.


The paper - 'The One Laptop per Child (OLPC) Audio Subystem' by Jaya (Alsa) provides useful information on the audio subsystem. The link is - The OLPC Audio Subsystem

Microphone Sensor Input

The microphone input can be used to measure voltage or (using the Microphone bias voltage) resistance. This should enable us to use this as a form of sensor input with the audio analog to digital converter converting the sensor signal to a signal that can be displayed on the screen or logged by the computer. More info is required on the use of the codec in this mode.

  • max voltage that can be withstood safely by the mic input
  • Voltage corresponding to AD converter full scale.
  • Bias voltage output (open circuit)
  • Bias voltage output (short circuit)
  • anything else?

Microphone data input

The microphone input jack can double as a dataport for some class of devices (when supporting a "DC-coupled" input mode), but a more general-purpose USB analog to digital device would be a great peripheral for the laptop. --Walter

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