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ah very sorry AD8400

Hi

I'm using an 18f4520 and trying to control a digitpot. In general this works perfectly for me.
I can configure the digipot at the start of my project to adjust a adc input to exactly 2.5V.

...

great

results seem a bit more solid now, as in I'm always getting the same thing.
I think this is probably going to be more down to how I'm providing/measuring my inputs but I seem to get increase ...

actually, one more quick thing. Any idea why my first result is always something way off. Think it used to be always 0xFFF but not sure what it is now.

matt

1)

SSPSTAT = 0x00; /* SPI status Register */
SSPCON1 = 0x21; /* SPI control Register 1 */

2) 10Mhz Crystal through HSPLL to 40Mhz

3) Should be 5V, comes in just above so using 5 ...

Hi, Im having a bit of trouble with my ADC. I do get results, and they are very close to what they should be. however they shift about an awful lot with each reading.

i.e. with a 4volt input i s ...

changing the position of the parity generation seems to have done it.

void send_byte(char c)
{

while(!bit_TXIF)
continue;
parity_errorGeneration& ...

I have concerns that using compiler functions might be called up by a safety board at a later date. Any experience of this with the likes of putc() ?

The USART takes care of parity if you use

...

example source
Im working on a PICDEM baord with a 10MHZ crystal. Aiming to work at 9600baud, odd parity

#include <18F4520.h>
#fuses H4
#fuses NOWDT
#fuses WDT128
#fuses NO ...

I'm having a bit of a problem with using the TXREG.

I'm trying to output a chain of hex values
00 A1 F2 C4 40 00 00 00 00 00 F0 00 01 01 00 00

when i use putc(); i get the correct 16bytes out. ...

Chip is the 18F4520.
My serial comms all work fine, which i guess is a good indicator that the clock/baud are working correctly

thanks for your help
matt

Hi, can i just re-assure myself by asking

is
#fuses H4 // HS/PLL

#use delay(clock=40000000)

all that is needed to set up a 40Mhz clock off a 10MHz crystal using pllX4?

...

well figured out the lag.
Stupidly enough i was reading the RX9D bit after reading from the RCREG, therefore clearing the register and reading the wrong RX9D.

might stick with this, and not use ge ...

Hi, thanks both for the replys

I believe the clockspeed is correct, it does measure 20 seconds. How would you fix this problem if it was off though? Set the baud manually instead of using #use RS ...

looks like the getc(); is causing the problem. Reading straight from the register works fine. Should have known better