Agnes en Henk Tobbe wrote:


>For a project I need an analoge adjustable RC-oscillator on a 16F84. Beinga
>newbe on PIC I dreamed up the following - not working - system (using PORT
B
>bits 6 and 7).
>set PB7 to output high,
>load a cap through a resistor out of this port (100K and 16 mf)
>monitor the level on the cap on PB6 as input
>As soon as PB6 is HI switch PB7 low to decharge the cap
>PB6 monitors this and on LO switches PB7 HI again
>and so on
>
>Basically the same as a small oscillator with a NAND gate or ST.
>
>It does not work, WHY? Where goes my reasoning wrong.
>Thanks
>Henk - V2GWK.


Do you have any timer running while you wait for cap charge? I am asking
this as your RC will take 1s+ to reach High level. Your watchdog is enabled?
If so try to disable it.

Marcelo Yamamoto
m_yamamoto@uol.com.br