• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

building digital anemometer with PIC

Status
Not open for further replies.

blibala

New Member
i have decided to build a digital anemometer/wind speed detector using PIC.
my system will work like this.when the wind blows, it will rotate the shaft and the slot disc mounted below it.i am using IR emitter and detector. when the slot disc rotates, it will cut the IR light beam and produces pulse. this pulse will then send to 74161 counter.
the problem arises at this stage. how do i interface the counter to the PIC and LCD display.
i am wondering what is the way to interconnect the PIC16F84A, counter and LCD display.......or and enhancement suggestion to my system?
anyone can help me?
 

motion

New Member
You don't need the 74161 counter. Just feed the output of the sensor directly into the PIC. You can use the PIC's internal counter. For example, if you are using the 16F84A, you can connect to pin RA4 which is the input to Timer0 when setup as an 8-bit counter.

However, you might consider using the PIC16F627 which is a newer replacement to the 16F84A. It has additional timers needed to calculate the wind speed.
 

blibala

New Member
[motion] can u show me some simple commands on how to program the 16F84A chip so that it can function as the counter?and how to connect to LCD display.
i just learnt PIC 2 weeks ago.so i afraid i do not know so much about the chip.
motion said:
You don't need the 74161 counter. Just feed the output of the sensor directly into the PIC. You can use the PIC's internal counter. For example, if you are using the 16F84A, you can connect to pin RA4 which is the input to Timer0 when setup as an 8-bit counter.

However, you might consider using the PIC16F627 which is a newer replacement to the 16F84A. It has additional timers needed to calculate the wind speed.
 

olly_k

Member
You know there is another way to detect wind speed??? with just TWO SENSING components a PIC and NO moving parts??? With FOUR sensing components you can judge wind direction as well but that gets more complicated....


Answer: Ultrasonic transducers! :D

However it may be a good idea to start simple at first and make that a later project!

If you are interested EPE magazine did a few articals starting with a 2 sensor wind speed measurer and then going full-blown with a solid state weather station. I shall try to dig out the mags and tell you which ones they were!
 

olly_k

Member
olly_k, were they using the Von Karmann Vortex method?
The What Method???

Hmmm, don't think vorteses have any influencing factor I suspect they would only confuse things!
VERY breifly it consists of four ultrasonic transducers pointing at each other from four corners of an imaginary square, with known distance between each one. Transducer 'a' will start and send a ping and this will be picked up by any one / two of the other three transducers, depending on wind direction and speed. Each transducer takes it's turn to transmit while the others 'listen'. The strength and length of time it takes for the transducer/s to receive the signal determines the wind direction and speed, after some calculations that is.
A very clever and very accurate way accomplishing what would have taken an anemometer and seperate whether vein to accomplish - with the benefit of no moving parts to wear down or add to errors through friction etc...The wind speed only version just had two ultrasonic transducers pointing at each other about 8cm apart.
I have also noticed that some meteorological stations employ this method now.
 

Eclipsed

New Member
The Von Karmann Vortex method uses a small vortex generator, and as air passes the generator ,It cause uniform vortices which are measured ultrasonically or by InfraRed.They are used in a lot of import automobiles, as engine airflow sensors.
 

olly_k

Member
ok, the magazine is Everyday Practical Electronics, @ www.epemag.wimborne.co.uk

the wind speed meter was in January 2003
and the whether station (speed and direction) I can't find right now but somthing like July or August. If I find it I will post an update!
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top