How to do CF hardware reset correctly?

[Tulkas]

CF hardware reset

I have a datalogger with a CF and pic18f452, when the card is full, i change the card by another one and reset the pic, software in the pic reset the CF. But when i use some cards i have to take the batteries from the datalogger because hardware reset doesn't work, after a reset of the pic the CF remains stopped. How can i do a hardware reset correctly?.

Thanks.

 

[nooknikz]

Re: CF hardware reset

CF Card Reset by Active High , You can jump reset pin to Vcc for reset .

below , it reset by software.

output_low(CF_RESET);
.
.
.
.
void cf_reset_fn() { // reset function
output_high(CF_RESET);
delay_ms(10);
output_low(CF_RESET);
}

 

[ericmar]

Re: CF hardware reset

I have a datalogger with a CF and pic18f452, when the card is full, i change the card by another one and reset the pic, software in the pic reset the CF. But when i use some cards i have to take the batteries from the datalogger because hardware reset doesn't work, after a reset of the pic the CF remains stopped. How can i do a hardware reset correctly?.

Thanks.

Hi, may I know how u implement ur datalogger with a CF and PIC18F452?

Thanks!

 

[Tulkas]

Re: CF hardware reset

I have used ad7706 from Analog Device and a RTC from Phillips. Basically, the pic is reading constinuosly channel 1 from ADC, when it has read 1024 bytes (for example) they are written to the CF, specifying the number of sectors to write (2 in this case). Every hour, the pic reads the time from RTC too.

CF is conectted to the pic across an interface (CF - IDE).

I'm using CF in true ide mode(in true ide mode CF reset by active low), if I remove the card from the socle and insert it again, after a reset of the pic everything is OK, but with some cards i have to disconect them from the batteries because they do not answer well after reset, if i read the status register everything seems to be correct but data that i read is bad. For example, when i send an identify command it answer to me like this : 'ΛΛΛΛΛΛΛΛΛΛΛΛΛΛΛΛΛΛ......etc etc'

Sorry for my english

Thanks.

 

[cube007]

CF hardware reset

Hello Tulkas,

Some CF cards have problems to get into TRUE IDE mode after hardware reset. I had some cards where it was only possible to bring them into TRUE IDE mode when powering up the device. I think that’s the reason why some designs are using a MOSFET for switching the power supply of the CF card off and on after detecting that the card was changed.


Bye,
cube007

 

[Tulkas]

Re: CF hardware reset

Thank you very match. My CF adapter (IDE-CF) don't have card detect lines (they are connected to GND), because of it i have had to put a switch, before changing te card i disconnect it.

Thanks.