Comments on: Arduino Ethernet Shield MEGA hack

By: daveosx

daveosx — Fri, 16 Apr 2010 05:58:41 +0000

Thank you works great!

By: toffe82

toffe82 — Tue, 09 Jun 2009 21:23:20 +0000

I finally made it works.
It was so obvious that I should have see it before ( 2 days to find out )
BIT0 is the original SS signal on the Arduino Mega but on the Duemilnove, it is BIT2.
My configuration is SS on pin8 (bending the pin 10 of the ethernet shield and making a jumper between 8 and 10 on the ethernet shield), the other pins don’t move.
The code is :
#define SPI0_SS_BIT BIT0
…
#define SPI0_SCLK_BIT BIT5
…
#define SPI0_MOSI_BIT BIT3
…
#define SPI0_MISO_BIT BIT4
…
#define IINCHIP_CS_BIT BIT0
…
PORTB |= SPI0_SS_BIT | BIT2; PORTB &= ~(SPI0_SCLK_BIT|SPI0_MOSI_BIT);\

By: toffe82

toffe82 — Mon, 08 Jun 2009 05:28:23 +0000

It is what I have done, when using pin9 I used bit 1 portB for SPI0_SS_BIT and IINCHIP_CS_BIT and I also put bit0 in PORTB |= SPI0_SS_BIT | BIT0 and it doesn’t work. The 3 other pins are standard connection of the etherent shield on the duemilnove.
I use the webserver example from the ethernet library (it is working in normal configuration) but in this case it pass server.begin() and stop there.
Perhaps I miss something or there is a difference between the mega and the duemilnove and I can’t use pin 8 or 9 ??

By: admin

admin — Fri, 05 Jun 2009 21:48:23 +0000

When you move SS to another pin, you need to follow the software hack at the end of the post, the BIT0 hack… and it is better to keep it within PORTB, as changing PORT can require more changes to the code

By: toffe82

toffe82 — Fri, 05 Jun 2009 21:40:05 +0000

I need this kind of hack on the duemilnove because I want to use the pin 10 pwm but I couldn’t make it work.
I move the ss on pin 9 and change the code accordingly(BIT1 instead of BIT2)and it doens’t work, any idea ?
I try also pin 8.