[En-Nut-Discussion] AT91 SPI Bus crash.

Pilou plc66.aus at gmail.com
Wed Nov 23 01:33:14 CET 2011

Good day all,

I am new on this mailing so here's my greetings and congrats for the 
amazing work provided around Nut/OS.

I have been stuck on a problem with the SPI implementation on a 
AT91sam7x512, with Nut/OS 4.8.9.

I have connected a WS2801 LED strip to the spi0 port of the board.

It works on a rough SPI bus implementation (only SPClk and MOSI/Data 
lines).  The CS0 pin is left as is.

To allow the transfer I have shorted MISO and MOSI for loopback , and I 
got to the stage where I can send one data block (3 grayscale on 8 bits 
x Num_LED = 1152 bits) and the board "crashes". The LEDs are lit 
according to the data I sent, so the transfer itself seems to work 
without any problem.
I am quizical about the line 318 in spibus0at91.c :
NutEventWait(&node->node_bus->bus_ready, NUT_WAIT_INFINITE);

I reckon the bus_ready event is ignored , possibly due to the mutex ... 
any thought ?

This problem has been mentioned earlier ( here : 
http://old.nabble.com/SPI-on-Arm7-%28EIR%29-Board-td32415281.html ) 

Best regards,

Pierre-Louis CONSTANT

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