Picbasic MMC SD : sdfs3.bas

[mackrackit]

What errors are returned?
For example, what do you receive here?

Gosub FSInit
	Serout2 PORTC.6, 16780, ["Init: ", Dec FAT_error, " ", Dec SDC_status, " ", Dec SDC_response, $d, $a]

[iw2fvo]

Hi,
I receive :
" init: 6 2 0 "
" init: 6 2 3 "
" init: 8 6 0 "

and others ... at random.

Thanks
Ambrogio

What errors are returned?
For example, what do you receive here?

Gosub FSInit
	Serout2 PORTC.6, 16780, ["Init: ", Dec FAT_error, " ", Dec SDC_status, " ", Dec SDC_response, $d, $a]

[mackrackit]

I am away from the shop but I think the feed back is telling you the card is not present.

I am sure you have, but double check the hardware.
Are you using a socket for the SD card or some other way. I was using a two row header at first myself and had the problem of getting a good connection at times. Make sur you have the pins aliased correctly, another mistake I have made.

Do you have a schematic or a good picture of the hardware?

[iw2fvo]

Hi,
I am using a Futurlec mini_board as a card receptacle. The card present LED on the board is on.
The WP and CD disretes at the PIC input are at low level.
I will check the hardware again just to be sure 100%. I will come back again to you as soon as I do have check it.
Thanks again for the interest on my project.
Bye
Ambrogio

I am away from the shop but I think the feed back is telling you the card is not present.

I am sure you have, but double check the hardware.
Are you using a socket for the SD card or some other way. I was using a two row header at first myself and had the problem of getting a good connection at times. Make sur you have the pins aliased correctly, another mistake I have made.

Do you have a schematic or a good picture of the hardware?

[mackrackit]

Card present is just a switch. I do not use that myself. You could put anything in the socket and make the LED light.

It is used with SDFS if you want to detect a card and force the code to re-initialize for a new card with out a power cycle, "hot swap".

At this time do not use it. Just more stuff to debug.

If you have an 18F4550, or equivalent, to connect like the example might also be a good place to start.

[Bruce]

Just a quess since I don't have your hardware to test;

With the card operating on 3.3V and the PIC on 5V, you should change to a port with
TTL inputs. Or use some type of buffer, or a PIC that will operate on 3.3V at whatever
osc speed you need.

PortC on the 18F452 are Schmitt Trigger type inputs that need higher threshold voltages
for logic 1 than TTL inputs.

[iw2fvo]

Hi Bruce,

I do have a resistor voltage divider 1k8_3K3> to gnd for the signals that go from PIC to MMC. The MMC output goes directly to PIC input portc.4 pin 23.
Could be that the card output level it is not enough to be reconized by the PIC s/t input....
I will really try with a level shifter and 18f452.
Any suggestion for a DIL ( not SMD ) device to be used for voltage shifting ?
Thanks a lot for the help.
Regards,
Ambrogio

Just a quess since I don't have your hardware to test;

With the card operating on 3.3V and the PIC on 5V, you should change to a port with
TTL inputs. Or use some type of buffer, or a PIC that will operate on 3.3V at whatever
osc speed you need.

PortC on the 18F452 are Schmitt Trigger type inputs that need higher threshold voltages
for logic 1 than TTL inputs.

[iw2fvo]

I do not have the pic18f4550 in m hands now.
Do you use the SDFS program or do you have other programs in basic ?
Have you a timed bit interface declaration for the MMC SD ?
Any time history diagram available just to try with a simple comands and response? Where can I found it on the WEB ? I will like to try with a very simple program ...
I will order that PIC but it will require some time.
Do you have in mind some kind of level shifter DIP ( not SMD ) to be used ?
Thanks
Ambrogio

Card present is just a switch. I do not use that myself. You could put anything in the socket and make the LED light.

It is used with SDFS if you want to detect a card and force the code to re-initialize for a new card with out a power cycle, "hot swap".

At this time do not use it. Just more stuff to debug.

If you have an 18F4550, or equivalent, to connect like the example might also be a good place to start.