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krusty
01-19-2006, 06:30 AM
my project has a problem....

i am trying to read values from the lm35 temp sensor, a humidity sensor cap and an ldr, then display the results on the·velleman lcd (at least that works!!)

i am using a·stamp bs2, connected to the components via·the RCTime·idea, with 1k resistors and 0.1uf caps··(tried both ways round vcc + vdd) and i dont get any steady readings.http://forums.parallax.com/images/smilies/shakehead.gif
example of humidity sensor using debug screen (same as on lcd..)
cycle 1 = 7668
cycle 2 =·7383
cycle 3 = 6951 etc etc etc.....

any experts care to share a little knowledge?

best regards

krusty

Newzed
01-19-2006, 06:38 AM
What kind of readings are you getting on the LM35?· Are they stable?

Sid

krusty
01-19-2006, 06:52 AM
mmm how is it best configured for your mind? capacitor on vcc or vdd?

br
krusty

Newzed
01-19-2006, 07:10 AM
If the above post was for me, the LM35 should have a 1K resistor in series with the sensing lead and a .1uf bypass on the ADC pin that is reading the LM35.

krusty
01-19-2006, 07:52 AM
@newzed

TEMP IS READING 202 - 209 with cap on data and gnd pins.

humidity is giving readings of 5183 upto 7916.

these readings were taken over 30 seconds

the LDR also has a wide variation of readings, but this isnt a problem.

Newzed
01-19-2006, 08:08 AM
What ADC are you using?· How many bits?

Sid