Youth deterent!

[jgu1]

Hi!

I am trying to create/convert the "youth deterent" from Bert v Dam´s book from FC5 to FC7. But when I compile the program I get "error code 1"
and it have something to do with tmr0, I use the C command: tmr0=0x195;

It work in FC5 but not in FC7. Can anybody tell me what I am doing wrong please?

Br Jorgen

[Benj]

Hi Jorgen,

In v7 you need to capitalise the register name to work with the xc8 compiler.

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TMR0 = 0x195;

Also your value looks wrong, should this be 195 instead of 0x195? 0x195 is a 12-bit value and the TMR0 regiser is an 8-bit register.

[jgu1]

Hi Ben!

Thank´s again for REALLY fast reply. And it work.

Br Jorgen

[medelec35]

Hi Jorgen,
Deterrent will not work on hardware unless you change Clock source select within Interrupt properties from:

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Transition on T0CKI pin 

to

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Internal clock.

Otherwise intrerrupt will be waiting for a change on T0CKI pin.

Martin

[jgu1]

Hi Martin!

No I see now when you spotted this, of course, thank´s. I have to test it later on hardware. I could not understand why I not was able to compile.

My goal is, to create random frequencies from16Khz to 40Khz in approx. 2-3 kHz step. I have to measure how high the freq is if I set TIM0 to:
TMR0 = 0x254;

Thank´s Martin for spotting.

Br Jorgen

[medelec35]

Your welcome.

TMR0 = 0x254;

You have got that wrong!

Values are:
Decimal:

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TMR0 = 0; 

to

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TMR0 = 255;

or
Hex:

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TMR0 = 0x0; 

to

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TMR0 = 0xFF;

Although in practice you would not go too near the highest value of dec 255 or hex 0xFF

Martin