Hello.
I'm studying mega162 chip and trying to implement SPI slave capability. I wanna send 8 bytes to master side and after reaching last byte get back and send again, ie continuosly.
Later I'd like to implement receiving.
So, I made the following simple code:
#include #include #include
char *data = "12345678"+0x00; char *t;
void SPI_SlaveInit(void) { DDRB = (1
"Roman Mashak" skrev i melding news:co3upp$2igu$ snipped-for-privacy@mpeks.tomsk.su...
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I haven't studied all your code, but I found two major errors:
- You have to wait for the previous byte to be sent before you write a new value to SPDR. Something like this:
- You should write whatever data points at to SPDR, not the pointer value itself.
while (1) { if (SPSR & (1
Hello, Jan! You wrote on Thu, 25 Nov 2004 09:01:04 +0100:
Jl> I haven't studied all your code, but I found two major errors: Jl> - You have to wait for the previous byte to be sent before you write a Jl> new value to SPDR. Something like this: Jl> - You should write whatever data points at to SPDR, not the pointer Jl> value itself.
Jl> while (1) { Jl> if (SPSR & (1 data = t; Jl> } Jl> SPDR = *data; Jl> data++ Jl> } Jl> } Thank you for help with C, but unfortunately problems still remains. I suppose, it's hardware related...
With best regards, Roman Mashak. E-mail: snipped-for-privacy@tusur.ru
Hello, Jan! You wrote on Thu, 25 Nov 2004 09:01:04 +0100:
Jl> I haven't studied all your code, but I found two major errors: Jl> - You have to wait for the previous byte to be sent before you write a Jl> new value to SPDR. Something like this: Jl> - You should write whatever data points at to SPDR, not the pointer Jl> value itself. By the way, while debugging this code in AVR studio (after modification according to your notes) I noticed that data put into SPDR register are strange. Originally I'm sending string "12345678", but character codes stored into SPDR are 0x31, 0x32, 0x33 etc.
Why ? Jl> while (1) { Jl> if (SPSR & (1 data = t; Jl> } Jl> SPDR = *data; Jl> data++ Jl> } Jl> }
With best regards, Roman Mashak. E-mail: snipped-for-privacy@tusur.ru
That is correct. A 0x31 is the hexadecimal ASCII code for character '1',
0x32 for a '2' and so on....Meindert
Hello, Meindert! You wrote on Thu, 25 Nov 2004 12:27:56 +0100:
??>> By the way, while debugging this code in AVR studio (after ??>> modification according to your notes) I noticed that data put into ??>> SPDR register are strange. Originally I'm sending string "12345678", ??>> but character codes stored into SPDR are 0x31, 0x32, 0x33 etc.
MS> That is correct. A 0x31 is the hexadecimal ASCII code for character MS> '1', 0x32 for a '2' and so on.... oh,, sorry for my stupidity :)
Anyway, I still don't get output signal looking at oscilloscope. I believe, I should make on slave side some checking of SPI is ready, SS checking or similar?
With best regards, Roman Mashak. E-mail: snipped-for-privacy@tusur.ru
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