LCD Frequency Meter

[InfernoJaffa]

Hi everyone!

I have a project that i need help on starting.

I have a flow transducer that outputs a frequency range which changes at different water flow rates.

I would like to convert this frequency output into a litre/minute calculation on a LCD display.

I am a novice, any tips or directions? Any help is welcome!

 

[Nigel Goodwin]

Use a microcontroller.

 

[InfernoJaffa]

Yes I have looked into this but unaware of which microcontroller to use. I have a MPLAB In-Circuit Programmer.

 

[Nigel Goodwin]

Yes I have looked into this but unaware of which microcontroller to use. I have a MPLAB In-Circuit Programmer.

The use a PIC, what is the frequency range of the transducer?.

 

[InfernoJaffa]

The use a PIC, what is the frequency range of the transducer?.

The datasheet for the flow sensor can be found here; **broken link removed** .

 

[ronsimpson]

Is this a hobby or a "work" project?

 

[InfernoJaffa]

Is this a hobby or a "work" project?

This is a hobby with resources from work.

 

[Nigel Goodwin]

The datasheet for the flow sensor can be found here; **broken link removed** .

Nice and slow then, so should be an easy enough job to do.

 

[InfernoJaffa]

Nice and slow then, so should be an easy enough job to do.

Thanks! Any starter hints/tips?

 

[Nigel Goodwin]

If you check the EPE website, they have published a number of counter projects, or MicroChip have an appnote for a frequency counter.

 

[InfernoJaffa]

If you check the EPE website, they have published a number of counter projects, or MicroChip have an appnote for a frequency counter.

Hi Nigel,
Thanks for your reply, I have looked at the microchip appnote using a PIC16C54 and found that the source code snippet is written in assembly language. I have done little assembly at college but feel that the C language would be a wiser choice for me. I also tried searching for the EPE website you had mentioned and found a site called EPEMag, was this the one you meant? I couldn't find much on that website.

I have found other projects using an Atmel chip with easy to understand source codes although programming the chip will not be easy. I would like to design the PCB board to include on-board programming as this will be easier to reprogram in the future (this should be a simple addition at the end).

The PIC chips I used at college were PIC16F84A and were programmed in assembly language.

Edit: I have learnt that I can connect the frequency directly to timer1 and measure the counts over a 1 second period. I can then take the value from timer 1 and calculate and display the flow rate.

I have attached a flow chart of what I would like the PIC to do.View attachment 61806



Can anyone suggest a good PIC to use, I have found the PIC 16F874 with Timer1 function although it seems to have more features then I need (40Pins).

 

[InfernoJaffa]

I have found another PIC chip called PIC12F683. Simple 8 pin chip with Timer1.

A simular project I have found when using this chip is https://picboard.blogspot.com/2010/09/experiment-no-6-pic12f683-timer1-used.html . Althought this is not connected to a LCD display (does this chip support this?).

 

[Nigel Goodwin]

I have found another PIC chip called PIC12F683. Simple 8 pin chip with Timer1.

A simular project I have found when using this chip is https://picboard.blogspot.com/2010/09/experiment-no-6-pic12f683-timer1-used.html . Althought this is not connected to a LCD display (does this chip support this?).

It's only an 8 pin chip, so it doesn't really have enough pins to connect an LCD - but an 18 pin one does.

 

[InfernoJaffa]

Thanks for verifying this Nigel.

I have found this https://www.best-microcontroller-projects.com/pic-frequency-counter.html online and plan to follow it, I will then edit the output to calculate flowrate instead of frequency. Hopefully it's as easy as that .
Just have to source the components.

I will let you know how I get on and if anything unexpected jumps out at me.

 

[InfernoJaffa]

Can anyone tell me the difference between these two PICs:
PIC16F887-I/P 20MHz - £1.89
PIC16F877A-I/P 20MHz - £4.09

I have chosen the PIC16F877A but in terms of cost the difference is 'noticeable'.

 

[mvs sarma]

please see the ratees here
that much difference is not found.
https://uk.rs-online.com/web/c/?sra=oss&searchTerm=pic16F877&x=0&y=0
neither here there is such vast difference.
https://uk.farnell.com/jsp/search/b...search&Ntt=pic16f877&Ntx=mode+matchallpartial

 

[InfernoJaffa]

please see the ratees here
that much difference is not found.
https://uk.rs-online.com/web/c/?sra=oss&searchTerm=pic16F877&x=0&y=0
neither here there is such vast difference.
https://uk.farnell.com/jsp/search/b...search&Ntt=pic16f877&Ntx=mode+matchallpartial

Thank you!

 

[Nigel Goodwin]

Can anyone tell me the difference between these two PICs:
PIC16F887-I/P 20MHz - £1.89
PIC16F877A-I/P 20MHz - £4.09

I have chosen the PIC16F877A but in terms of cost the difference is 'noticeable'.

The 877A is a very old device, similar to the 16F84A - modern devices are MUCH cheaper, presumably to encourage people to stop using the antique ones

Presumably the 887 is the modern replacement for the 877?.

 

[mvs sarma]

Sorry , perhaps i mistook both for 877

 

[InfernoJaffa]

The 877A is a very old device, similar to the 16F84A - modern devices are MUCH cheaper, presumably to encourage people to stop using the antique ones

Presumably the 887 is the modern replacement for the 877?.

Thanks for confirming this, so I should be fine in using the newer chip as a replacement without any issues?