Hey All,
I'm working on my first Arduino project...And I some questions about shield compatibility.
My project is basically a my own spin on "Big Mouth Billy Bass" - Big Mouth Billy Bass - Wikipedia type of installation....
I have a basic prototype working using these parts:
Arduino Mega 2560 Rev3
Wav Shield
PIR Motion Sensor
Servo
How it's working now is:
- The sensor detects motion.
- A WAV file is played.
- While the file is played a servo moves in relation to the voltage output of the WAV shield.
I had to "hack" the wav shield to work with the Mega Board by remapping these pins with jumpers:
The cable going from the "CCS" hole on the shield connects with the digital pin 53 on the Mega.
The cable going from the digital input/output hole 11 on the shield connects with the digital pin 51 on the Mega.
The cable going from the digital input/output hole 12 on the shield connects with the digital pin 50 on the Mega.
The cable going from the digital input/output hole 13 on the shield connects with the digital pin 52 on the Mega.
http://forums.adafruit.com/viewtopic.php?f=31&t=10939
I'm looking to further expanding my project by adding the ability to connect to the internet using the WiFly shield and adding Text to Speech with the SpeakJet Shield. I'm thinking of making a Twitter parser that will read out tweets with a certain hashtag.
The WiFly shield uses Arduino digital pins 10-13 (CS, MOSI, MISO, SCLK respectively)...which are ALSO used by the WAV shield...If I'm not using these two shields at the same time, can they be stacked together or do I need to do physical pin or software remapping?
The SpeakJet Shield uses digital pins 2, 3 or 4. Does anyone see any reason why this might not be compatible with the existing hardware I have?
Would appreciate any tips or advice you have to offer about this project.
From what you've typed, the WiFly and Wav shields you're thinking of using both use the SPI interface, which allows for one master (your Arduino in this case) and multiple slaves (these shields) to interoperate together over the same 4 wires. More general info here: Serial Peripheral Interface - Wikipedia . Bottom line is I don't think that should present a problem, though I've not got either of them to confirm from experience.
If it's the Adafruit Wav Shield, it uses that SPI interface for the SD card slot (Audio Shield for Arduino - FAQ explains pin-outs) and some of the other pins you mention for the Speakjet Shield are also used by that sheild unless you wired it up differently when you assembled it, or you can always rewire it to suit what you need to do.
You do have a mega though so you've got lots extra pins to play with.
I actually have one of those singing fish things in a cupboard somewhere...you remind me I should pull it apart and see what made it tick 
Strykeroz,
Thanks for the feed back and links.
I am using the Adafruit WAV shield. So to use the SPI interface for both WiFly AND the WAV shield, I just need to jump the Mega's SPI pins are 50, 51, 52 and 53 out to a bread board to share them between both shields? How do I wire the Slave Select pin? From what I've read, it seems that the SS pin has to be unique for each device. Does anyone have examples of how to wire up two shields that use SPI on a Mega?
I guess I should do more research to see if sharing the SPI interface for two different shields at the same time will be a problem...
The Speak Jet shield uses digital pins 2, 3, 4 (which conflict w the WAV shield)....and it seems they can't be remapped.
So it looks like I need to move the jumpers on the WAV shield from 2, 3, 4 to any of these pins 6, 7, 8, 9 or the 6 analog in pins (also known as digital i/o pins 14-20) and reassign them in the library (Google Code Archive - Long-term storage for Google Code Project Hosting.) I'm using?
Fortunately I haven't soldered any jumpers to the WAV shield yet and I have lots of pins with the MEGA, so it looks like I have some flexibility.
