I'm controlling an Ethernet shield with an Uno, and I can get it to work.
However, I'm wanting to add another custom shield (of my own design) to the stack, and want to be sure that I avoid the pins used by the Ethernet shield.
This page [http://www.arduino.cc/en/Main/ArduinoEthernetShield] says that the Ethernet shield uses digital pins 10,11,12, and 13, and this would seem to be correct from looking that these pins with a scope. I also see activity on pin D1.
Additionally, my Ethernet shield looks like the one in the picture (except that I have a green LED in addition to the 3 yellow ones next to the xtal), though the white print is different and there's no print at all on the back side, so I'm unsure of I have an R3 or what.
However, I can't find an Ethernet shield schematic that agrees with this.
The schematic on the shield's page [http://arduino.cc/en/uploads/Main/arduino-ethernet-shield-06-schematic.pdf] does show pin D10 for SS (which agrees with the text), but the schematic seems to show the Ethernet shield using pins 1-5 on J3 (perhaps these are the Uno's D0-D4?) and nothing on pins 11-13. This schematic DOES show the green LED along with the 3 yellow ones.
Can anyone provide credible docs as to which pins the Ethernet shield does indeed use?
The pin use depends on the ethernet shield revision model. The main difference is the ICSP connector on the bottom of the shield. Does your shield have a 6 pin (2x3) header connector on the bottom at the back center of the shield?
The schematic you referred to has that connector. This is the new shield schematic.
It uses digital pins 0-4 and 10. However, on the Uno-like boards, digital pins 11-13 are SPI lines.
The R3 version has the connector and adds two new pins each to the power header and J1.
The older model does not have that connector, and uses different pins. http://www.cutedigi.com/pub/Arduino/arduino-ethernet-shield-schematic.pdf
It uses digital pins 2-6 and 10-13, along with analog pins 0 and 1.
Edit: that may be analog pins 4 and 5. I can't tell how the header pins are arranged on the older boards.
My shield does have the 6 pin ICSP header, thus it would seem to be the 06.
But I'm still confused as to the pin assignments; the 06 schematic (your link) shows no connections to pins 11-13.
Also: are you saying that, on the Uno:
a) The shield uses pins 11-13 INSTEAD of pins 0-4, or
b) That with Uno the shield uses 11-13 AND ALSO USES pins 0-4.
dlchambers:
My shield does have the 6 pin ICSP header, thus it would seem to be the 06.
But I'm still confused as to the pin assignments; the 06 schematic (your link) shows no connections to pins 11-13.
Also: are you saying that, on the Uno:
a) The shield uses pins 11-13 INSTEAD of pins 0-4, or
b) That with Uno the shield uses 11-13 AND ALSO USES pins 0-4.
The new shield (yours) uses digital pins 0-4 and pin 10. Pins 11-13 (on the shield) are not connected for Mega compatibility.
The new setup for the ethernet shield (for both Uno and Mega) is to use the SPI data line pins on the ICSP connector.
On the Uno, the ICSP SPI pins are connected to pins 11-13, but not used by the new shield
On the Mega, the ICSP SPI pins are connected to pins 50-52, but also not used by the shield.