On Sat, Jun 2, 2012 at 12:59 AM, John Watlington <[email protected]> wrote:
> > On Jun 1, 2012, at 9:24 PM, [email protected] wrote: > > >> We should test the calibration again. > > Walter, Guzman > > > > Testing with TA140 > > > > It looks like the 1.75 audio circuit was changed between the > preproduction and the ramp unit 1.75's > > > > Testing on SKU199 and SKU204, the impedance has gone from 1k to 4k and > the calibration is all wrong on 204 > > > > (TA calibration should be OK for the moment on preproduction SKU199) > > > > Can laptop.org please confirm that there was an audio redesign between > SKU199 and SKU204? Is the SKU204 design now stable or can we expect further > changes? > > Yes, there was a redesign which increased the resistance between the Mic > voltage source and the mic jack > from roughly 1K to roughly 3K for improved microphone performance. All > production XO-1.75s use the SKU204 circuitry. > See http://wiki.laptop.org/go/XO1.75_B1_C1_Changes > > > Is the input protection the same as the 1.5: "The XO-1.5 is protected by > a resistor,(1/16W 470 ohm SMD0402) and a pair of diodes to ground and to > +3.3V which should protect -6V to +9V continuously, and up to higher > voltages for shorter periods of time." > http://wiki.sugarlabs.org/go/Activities/TurtleArt/Using_Turtle_Art_Sensors#Specifications > > Yes, the protection circuitry is the same as used on 1.5. > > Chers, > wad > > _______________________________________________ > Devel mailing list > [email protected] > http://lists.laptop.org/listinfo/devel >
_______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
