Pico Technical Support and Discussion Forum

meiyueh · Newbie Joined: 25 Apr 2005 Posts: 1

my project is stated as abv. i'll use the drdaq to detect sound of coin dropping n use picoscope to display the signal n at last use vb to analyze it. the last result is the vb will differentiate each type of coin.

i'll use brick as a base for the coin to drop. but i have to do a casing to isolate the noise tht will afffect the result i get? what kind of material is suitable as casing ?

if i set the picoscope trigger to none, the signal will be continuous and i can't save the coin dropping sound then. So i set the trigger to single. but smtimes when i just press the button go in the picoscope, the noise will be detected b4 i drop the coin, so the vb will just analyse the noise and error will occur.is it the picoscope is really sensitive and nt stable? or i really need a casing for the drdaq to isolate noise, and i can detect the coin dropping only?

thx a lot for ur help.

Sarah · Guest

Hi

Thank you for your post.

Whilst it is possible to use the DrDAQ in this way I would advise you that the microphone and DrDAQ unit is not desgined for in-depth signal analysis. It is more designed for educational use in enabling students to see a sound-wave graphically. You should keep this in mind and may instead find our ADC-216 a better unit as this is designed for audio analysis.

Firstly, with regards the trigger, I would simply change the trigger threshold so that it is higher and thus would not trigger from just noise.

For making an enclosed space you will need to research various ways of acoustically dampening the space. Essentially you want to use a material which would absorb sound rather than reflect it - such as foam (special acoustic foam is available from some companies for a better result).

Hope this helps

Best Regards

Pico Technology

Pico Technical Support and Discussion Forum