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Forum Index : Microcontroller and PC projects : MM and the HH10D

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palcal

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Joined: 12/10/2011
Location: Australia
Posts: 1873

Posted: 10:43pm 08 Jan 2012

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Yes me again with another problem. I have a humidity sensor which gives out a frequency depending on humidity. I have it connected to pin 11. With no program in memory if I type into the keyboard;
SETPIN 11,3
PRINT PIN(11)
it gives me the frequency in Hz.
However if I write a two line program;
10 SETPIN 11,3
20 PRINT PIN(11)
RUN
it gives me a zero
Anyone know what I am doing wrong.
Paul.

"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all"

JohnS
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Joined: 18/11/2011
Location: United Kingdom
Posts: 3800

Posted: 10:47pm 08 Jan 2012

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At a guess, not giving it time? Delay a little between the lines?

CircuitGizmos

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Joined: 08/09/2011
Location: United States
Posts: 1425

Posted: 11:40pm 08 Jan 2012

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That should be it. In order to measure a frequency, you have to give the MM a chance to measure that frequency. I would suggest:

10 SETPIN 11,3
15 PAUSE 2000
20 PRINT PIN(11)
RUN

Micromites and Maximites! - Beginning Maximite

seco61
Senior Member

Joined: 15/06/2011
Location: Australia
Posts: 205

Posted: 11:58pm 08 Jan 2012

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Hi Paul.

See the code that was posted in your original HH10D post.

Remember that the MMBasic code will execute approximately 30000 lines of code a second. The HH10D will have an output frequency of around 5 - 10kHz. In the time that MMBasic has executed 2 lines of code you will see a value of 0 or 1 returned. For an accurate frequency measurement you will need to wait at least a second between readings, and between setting the pin to frequency measurement and using the value.

Regards

Gerard (vk3cg/vk3grs)

palcal

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Joined: 12/10/2011
Location: Australia
Posts: 1873

Posted: 12:13am 09 Jan 2012

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Thanks all, I now remember seeing that somewhere, problem solved.

Paul.

"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all"

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