On Thu, 2012-03-29 at 11:28 +0200, M. Manca wrote:
> Il 29/03/2012 10:56, Phil Young ha scritto:
> >
> >
> > Looks like the resistor to ground is not connected and the resistor to
> > vdd is charging the input capacitance.
With a 464E resistor the input capacitor would be fully
charged and the conversion result must be 4095. I have
2 resistors connected and I wrote "expected adc result
of 2048", the actual result is around 2043. Given the
tolerances of the resistors, good enough for me to show
the OP that a simple circuit like this must work on the
lpc176x.
> I don't understand why you answer this to
roelof.
Me neither :-)
> Him results are good
> if he didn't calibrate the circuit given that he has connected just
some
> passives considering that the read data is 2043 instead of 2048.
True, I did not calibrate anything.
roelof
ADC Issue
Started by ●January 29, 2012
Reply by ●March 29, 20122012-03-29
Reply by ●March 29, 20122012-03-29
On Thu, 2012-03-29 at 10:54 +0100, Phil Young wrote:
> Maybe I misunderstood the table then, It looked
> like a value was increasing over time.
I used a simple routine to increase a value in the
buffer, this value position corresponds to the adc
result.
Hope I did explain it clearly :-)
roelof
> Maybe I misunderstood the table then, It looked
> like a value was increasing over time.
I used a simple routine to increase a value in the
buffer, this value position corresponds to the adc
result.
Hope I did explain it clearly :-)
roelof
Reply by ●March 29, 20122012-03-29
On Mar 29, 2012, at 4:03 AM, roelof 't Hooft wrote:
> On Thu, 2012-03-29 at 10:54 +0100, Phil Young wrote:
> > Maybe I misunderstood the table then, It looked
> > like a value was increasing over time.
>
> I used a simple routine to increase a value in the
> buffer, this value position corresponds to the adc
> result.
> Hope I did explain it clearly :-)
>
Thanks for doing this! I've been keenly watching this topic as an owner of both mbed and lpcxpresso and having possibly seen mbed issues myself in one instance.
Your result output is a histogram. My first thought was that it looked sort of like a gaussian distribution (hard to 'see' with just numbers in a glance, though). Cool.
Michael
> On Thu, 2012-03-29 at 10:54 +0100, Phil Young wrote:
> > Maybe I misunderstood the table then, It looked
> > like a value was increasing over time.
>
> I used a simple routine to increase a value in the
> buffer, this value position corresponds to the adc
> result.
> Hope I did explain it clearly :-)
>
Thanks for doing this! I've been keenly watching this topic as an owner of both mbed and lpcxpresso and having possibly seen mbed issues myself in one instance.
Your result output is a histogram. My first thought was that it looked sort of like a gaussian distribution (hard to 'see' with just numbers in a glance, though). Cool.
Michael
