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1  Using Arduino / Audio / SimpleSDAudio 16-Bit Playback Mono on: July 01, 2013, 05:25:41 pm
Hi there,

I am using SimpleSDAudio library on my Mega1280.

The hardware I have built is this:


However I am using PWM1 pin as 44 and PWM2 pin as 45 (given I'm using a MEGA).

The circuit/library works fine for .AFM files (8-bit Full Rate Mono) however I can't get anything to playback properly in 16-bit Full Rate Mono (.BFM files).

The constants I am using are: SSDA_MODE_FULLRATE and SSDA_MODE_MONO

Have I built the wrong circuit for 16-bit playback?

Thanks
2  Using Arduino / General Electronics / Re: FDN340P Drawn incorrectly on schematic? on: February 12, 2013, 04:45:36 pm
Cool, thank you vasquo! Good to know I'm not going insane!

yes my beef is the way the diode is drawn and hence ALSO the drain and source terminals.

In their schematic they have drawn the circuit symbol for a P MOSFET such that the Drain terminal of the mosftet is connected to the USB 5V when in fact they should have drawn it such that the source terminal is connected to USB 5V. Basically the MOSFET symbol is drawn back to front in their diagram.

I thought it was just a simple error in the schematic drawing, however I was doubtful given this error has been present since the Duemilanove schematics back in 2009.... I can't believe this hasn't been picked up on to date?
3  Using Arduino / General Electronics / Re: FDN340P Drawn incorrectly on schematic? on: February 12, 2013, 04:33:22 pm
Hi,

No I do not think it acts like a SPDT switch! Like I said, I am happy with the 'descriptive' purpose and operation of the MOSFET - i.e it is switching USB 5V either on or off. What I am not happy with is the way the terminals of the MOSFTET are drawn in the schematic.

Please see my attached image.

Circuit A is what has been drawn on the schematic.

I believe that what should have been drawn is Circuit B.

Any comments?

Thanks
4  Using Arduino / General Electronics / Re: FDN340P Drawn incorrectly on schematic? on: February 12, 2013, 03:58:45 pm
Thanks for the replies.

I understand and agree with the description of the operation you have both given, however the dispute I have is with specific terminals of the P MOSFET and how they are connected. When using a P MOSFET as a switch, the load (or circuitry to be switched) should be connected to the Drain of the MOSFET which has not been done in this schematic (they have connected the load to the Source).

The MOSFET switches using the Vgs (Voltage between the Gate and Source). I.e in this case the voltage between the output of the comparator and what should be the voltage of the USB 5V (however this is NOT what is drawn).

Does that make sense?

Thanks
5  Using Arduino / General Electronics / Re: FDN340P Drawn incorrectly on schematic? on: February 12, 2013, 02:29:33 pm
That was one of the first things I checked. All of the boards you mention have it drawn the same way - which I why I thought it couldn't be an error. However that goes against the operation of a P-channel MOSFET as a switch - which is how it is being used here.

Argh!!! Someone please clarify!

Thanks
6  Using Arduino / General Electronics / FDN340P Drawn incorrectly on schematic? on: February 12, 2013, 01:37:21 pm
Hi there,

I was just looking at the Leonardo schematic: http://arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf

Is is just me, or is the FDN340P at the bottom of the schematic drawn the wrong way around? Should the Source of this P-Channel MOSFET not be connected to the USB's 5V? In the schematic they have connected the Drain to 5V from the USB instead.

It might just be me, but would love clarification on this!

Thanks
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