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Nigel

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  • Do I need a new Apple ID to develop iPhone/iPad apps?

    I'm planning on writing some iPhone apps, and have an unpaid developer ID to get into the dev parts of the Apple website and download stuff like the Xcode suite and WWDC videos.

    I'm at the stage where I want to pay my $99 to deploy apps to my phone, but the note on this page confuses me: http://developer.apple.com/programs/start/standard...

    "Note: If you intend to enroll in a paid Developer Program for business purposes, you may prefer to create a new Apple ID that is dedicated to your business transactions and used for accounting purposes with Apple. If your Apple ID is associated with an existing iTunes Connect account, please create a new Apple ID to avoid accounting and reporting issues."

    Huh? Advice please - for example if I set up a new Apple ID will that cause problems with updating apps I've bought through iTunes? Will it mess up my current dev access? What is iTunes Connect and does it affect me?

    1 AnswerProgramming & Design1 decade ago

  • How do I filter a square wave to get an analogue voltage?

    Say I have a square wave, flipping between 0V and +6V, with a cycle of about 100Hz. How do I get from that to a flat analogue voltage that's between 0V and +6V?

    So, for example, the square wave is at 0V for 50% of the time and at +6V for 50% of the time, I want to have an output of +3V. And if, for example, the square wave is at +6V for 75% of the time, I'd want an output of a flat 4.5V. Same for all other variations.

    In effect I suppose this is a 1-bit DAC.

    I think I need something like one resistor and one capacitor - but what are their values and wiring?!

    Points to note:

    * The frequency of 100Hz isn't a definite value if it's easier for it to be something else

    * It doesn't matter if the system loses some voltage through the inefficiencies of the components

    * The conversion doesn't have to be exactly linearly proportional but close to a linear relationship would be ideal

    * What matters most is that the output would look virtually flat on an oscilloscope and can be smoothly varied between 0V and something near to +6V as the incoming square wave's peak and trough lengths are varied

    * Fewest possible components with smallest power drain is desirable; this has to run off batteries

    Thanks!

    4 AnswersEngineering1 decade ago