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This shows you the differences between two versions of the page.

--- guides:raspberrypi [2013/09/11 20:51] – [Radio] Link to advanced page mfa298
+++ guides:raspberrypi [2014/11/03 20:56] (current) – realflash
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 	* It's a bit large and heavy compared to most Arduinos
 	* It has an SD card poking out of the end (delicate)
-	* It runs Linux which is not a real-time operating system
+	* It will take some effort and Linux knowledge to run a real-time kernel on it
 	* Unlike the Arduino you don't have a large selection of shields to choose from
@@ Line 65: / Line 65: @@
 Another option would be to connect to the GPS using a different serial connection - i2c or SPI.  If you use i2c with a UBlox receiver you'll find it doesn't work, because the UBlox does "clock stretching" at arbitrary times, and the Pi ii2c driver doesn't handle that.  You may have to resort, as I did, to using a software "bit-banging" i2c implementation.
+Another option would be to use a PL2303 (USB To Serial) device. It's cheap (1€) and quite light. This is working great to discuss with the radio (NTX2) or with the GPS (Ublox). It has been used successfully for UGGY payload with 150 bauds for the radio. For the Ublox that have 3.3V logic, check if your PL2303 is 3.3V or 5V logic and adjust if needed (in case you still power the Pi with 5V). There is a Pin of the chip to unplug from the 5V, and plug to the 3.3V to change the serial logic.
 Typically we run the radio at 50 baud.  This is possible on the pi but when I tried it it worked for a few characters only.  I've had better results with 300, 600 and 1200 baud.  The Lassen GPS runs at 4800 baud and the UBlox at 9600 and neither can be reprogrammed down to low speeds, so this means that the tracker program needs to switch baud rates to read the GPS, then switch before transmitting.  And then back again.  So this all imposes some down-time between transmissions.
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 	* Make sure the serial port isn't doing NL --> CRNL conversion or similar (otherwise your binary image data is going to get messed up).
+** Update **
+For those using the PiCAM and Python there is a python module giving access to the camera rather than having to use os.system. This provides a cleaner interface and will potentially be much faster.
+Write up on raspberrypi.org can be found at [[http://www.raspberrypi.org/archives/5672]] with installation details at the bottom of the page.
+The project details are available on [[https://pypi.python.org/pypi/picamera/|PYPI]] and [[https://github.com/waveform80/picamera/|GitHub]]. The module is also installable via ''apt-get install python-picamera'' or ''apt-get install python3-picamera''
+**Update - NEW RASPBERRY PI ADD-ON BOARD**
+If this all sounds a bit too much work, you can use Dave & Anthony's [[http://www.pi-in-the-sky.com/|PITS]] add-on board for the Raspberry Pi!