MMC card SPI and USART with 18F AN1003 C18

[adbensi]

Hello, great full for you visit,

 I have difficult to make one project with firmware AN1003 to use MMC card memory and USART comunication, because the SPI port use the USART pins.

 It ís possible to use other library / firmeware with ANSI - C18/C30 or other microcontroler compatible to make this project? Please, help me, i need one sample code to know how to make it, i am studding it yet.

Best regards,
Alexandre.

[navaismo]

Maybe this can help you.

Its an example from the Mikrobasic's help

The following code tests MMC library routines. First, we fill the buffer with 512 “M” characters and write it to sector 56; then, we repeat the sequence with character “E” at sector 56. Finally, we read the sectors 55 and 56 to check if the write was successful.

Código: FreeBasic

1. program mmc_test
2.  
3. dim tmp as byte
4. dim i as word
5. dim data as byte[512]
6.  
7. main:
8.  
9.   Usart_Init(9600)
10.  
11.   ' Initialize ports
12.   tmp = Mmc_Init(PORTC, 2)
13.  
14.   ' Fill the buffer with the "M" character
15.   for i = 0 to 512
16.     data[i] = "M"
17.   next i
18.  
19.   ' Write it to MMC card, sector 55
20.   tmp = Mmc_Write_Sector(55, data)
21.  
22.   ' Fill the buffer with the "E" character
23.   for i = 0 to 512
24.     data[i] = "E"
25.   next i
26.  
27.   ' Write it to MMC card, sector 56
28.   tmp = Mmc_Write_Sector(56, data)
29.  
30.   '** Verify: **
31.  
32.   ' Read from sector 55
33.   tmp = Mmc_Read_Sector(55, data)
34.  
35.   ' Send 512 bytes from buffer to USART
36.   if tmp = 0 then
37.     for i = 0 to 512
38.       Usart_Write(data[i])
39.     next i
40.   end if
41.  
42.   ' Read from sector 56
43.   tmp = Mmc_Read_Sector(56, data)
44.  
45.   ' Send 512 bytes from buffer to USART
46.   if tmp = 0 then
47.     for i = 0 to 512
48.       Usart_Write(data[i])
49.     next i
50.   end if
51.  
52. end.

The next program tests MMC FAT routines. First, we create 5 different files in the root of MMC card, and fill with some information. Then, we read the files and send them via USART for a check.

Código: FreeBasic

1. program MMC_FAT_Test
2.  
3. const FAT_ERROR as string[20] = "FAT16 not found"
4. dim filename as string[14]
5. dim tmp, character, j as byte
6. dim size, i as longint
7. dim aux as string[5]
8. dim msg as string[100]
9.  
10.  
11. main:
12.  
13.   ' Set up USART for the read of the files
14.   Usart_Init(19200)
15.  
16.   tmp = Mmc_Fat_Init(PORTC, 2)  ' Try to locate the FAT
17.  
18.   if tmp <> 0 then
19.     for tmp = 0 to Strlen(FAT_ERROR) - 1
20.       Usart_Write(FAT_ERROR[tmp])
21.     next tmp
22.   end if
23.  
24.   j = 1
25.  
26.   '** Write test, 5 files **
27.  
28.   for j = 1 to 5                 ' We want 5 files on the MMC card
29.     filename = "MYFILE0xTXT"     ' File names, e.g. "MYFILE01.TXT", "MYFILE02.TXT"
30.     filename[7] = j + 48         ' Set number 1, 2, 3, 4, or 5
31.  
32.     Mmc_Fat_Assign(filename, 1)  ' Create the file, if not found
33.     Mmc_Fat_Rewrite            ' Clear the file and prepare for writing
34.  
35.     ' Form the text to be written
36.     aux = "  "
37.     aux[0] = j + 48
38.     msg = "This is a test file, no." + aux
39.  
40.     Mmc_Fat_Write(msg)  ' Write data to the assigned file
41.  
42.   next j
43.  
44.   '** Append test **
45.  
46.   ' Now let's add more data to the same files
47.   for j = 1 to 5
48.     filename = "MYFILE0xTXT"
49.     filename[7] = j + 48
50.  
51.     Mmc_Fat_Assign(filename, 1)  ' Find the file and "assign" it
52.     Mmc_Fat_Append             ' Prepare for appending
53.  
54.     ' Form the text to be written
55.     aux = " "
56.     aux[0] = j + 48
57.     msg = "Append test, try " + aux
58.  
59.     Mmc_Set_File_Date(2005,5,j,12,47,12)  ' Test the date function
60.  
61.     Mmc_Fat_Write(msg)   ' Write data to the assigned file
62.  
63.     '** Read test **
64.  
65.     Mmc_Fat_Reset(size)  ' Take the size of the file
66.  
67.     ' Send whole file to USART, char by char
68.     for i = 1 to size
69.       Mmc_Fat_Read(character)
70.       Usart_Write(character)
71.     next i
72.  
73.   next j
74.  
75. end.

[adbensi]

Hello navaismo!! 

You this using the serial communication USART to record data in the MMC card, this is very interesting.

Can to use TX USART to write in MMC, and RX USART to get the data to record from other PIC

I try to run this code, on page 231. Thanks a lott!! This compiler is more easy of C18 and different.

Best regards,
Alexandre.