Hello everyone,
I'm currently working on a raspberry Pi and an arduino Mini Pro. I send a video taken by the raspberry Pi to my arduino by SPI and i can display what i receive on the serial monitor. But actually i need to save what i receive in a text file because i have a code which allows me to reconstruct the video form the text file. To do this i'm trying to add a SD shield to the arduino but the SPI bus is already taken by the raspberry. I tried to plug the SD shield on the Arduino without the Raspberry and it's working but as soon as i try to do it for the final linking the SD cannot be recognized by the Arduino ( probably because of the Raspberry ).
Does anyone have already be confronted to this problem? any help is welcome 
zuzuzu:
Hello everyone,
I'm currently working on a raspberry Pi and an arduino Mini Pro. I send a video taken by the raspberry Pi to my arduino by SPI and i can display what i receive on the serial monitor. But actually i need to save what i receive in a text file because i have a code which allows me to reconstruct the video form the text file. To do this i'm trying to add a SD shield to the arduino but the SPI bus is already taken by the raspberry. I tried to plug the SD shield on the Arduino without the Raspberry and it's working but as soon as i try to do it for the final linking the SD cannot be recognized by the Arduino ( probably because of the Raspberry ).
Does anyone have already be confronted to this problem? any help is welcome
the SPI bus can be shared.
| Master | SD Shield | PI |
|---|---|---|
| MOSI | SIMO | SIMO |
| MISO | SOMI | SOMI |
| CLK | CLK | CLK |
| CS_SD | CS_SD | |
| CS_PI | CS_PI |
Each slave device needs its own ChipSelect (active Low) pin.
You need to describe how you have wired the MiniPro to the PI (pins connected on both ends).
How the SD shield is wired (what pin is used for CS on the Shield)
Which device is the SPI Master (controls the CLK)
if the Arduino is the Master then:
you need a CS_PI pin for the PI( which needs to respond as an SPI Slave device)
you need a CS_SD pin for the SD Shield (usually pin 10);
Does the MiniPro use 3.3V on the SPI?
Does the SD Shield use 3.3v on the SPI?
The problem you have experiencing is probably that both SPI slave are connected to the same CS pin, usually (SS = 10 for Uno's or SS=53 for Mega's)
Chuck.
Check out my Kickstarter Project Memory Panes an expansion RAM Shield for Mega2560's. It adds 1MB of RAM for those projects where 8KB is not enough.