LeafLabs Garden

A place to share, learn, and grow...

1. 

   gbulmer
   Moderator

   Did folks notice:
   http://www.raspberrypi.org/

   Raspberry-Pi has already sold the first batch of 10,000, in less than one day!-)

   I ordered mine too late to get one of the first batch.
   People are twittering April, and even May as the next available dates, but I'll wait to see what Farnell say.

   I believe both RS Components and Farnell are taking pre-orders.

   An R-Pi might be a nice machine for cross-development for Cortex-M because AFAIK the native C/C++ compiler is gcc. It isn't exactly the 'no-platform' version, but I believe a few flags will generate Cortex-M code. I assume folks will be putting IDE's on it 'like no tomorrow'.

   There may be effort to put LLVM on it too: http://www.llvm.org/ which might be interesting to experiment with.

   So we may have an extra few hundred thousand ARM developers coming along, sharpening the tools we use :-)

   Posted 1 year ago #
2. 

   crenn
   Moderator

   I ordered my Raspberry Pi a couple of days ago, as well as some other SMD components for a different project. Looking forward to having a play with it, and would love it if I can get it working with a Maple (not via the USB port) so that I can use the peripherals of the Maple with the 'grunt' of the RPi.

   At a later stage, I might be getting a couple of the Pis (Model A) ;D

   Posted 1 year ago #
3. 

   crenn
   Moderator

   And to dig up a really old topic, I got mine today! Can't play with it until tomorrow night, but I'll be seeing if I can't pair it up with a nice Maple ;D

   As for why I can't play with it.... 2 exams within hours of each other. Fun.

   Posted 11 months ago #
4. 

   juzza_s
   Member

   Well, the Raspberry PI has 8x GPIO, I2C, SPI and a UART, so it shouldn't be a problem for the two boards to chat to each other.

   http://elinux.org/RPi_Low-level_peripherals

   Now to decide what interface to use. :-)

   I'll be interested to know how you get on, because my project will have a similar setup when I get my RPi.

   Posted 11 months ago #
5. 

   crenn
   Moderator

   I've been planning on using the SPI interface for a while and assisted someone test a SPI module with a ATMega168 :D

   Posted 11 months ago #
6. 

   juzza_s
   Member

   SPI. Interesting . . . . I like it!

   Now you've given me food for thought! :)

   Posted 11 months ago #
7. 

   gbulmer
   Moderator

   I got mine last week, but I'm doing some work which will keep me busy until next week.

   I proposed SPI and an ATmega on some of the 'physical computing' threads at the R-Pi forum last year, so I'd be interested in how well it works.

   The reason to use SPI to an ATmega is more than a fast comms. mechanism.
   ATmega's are programmed over SPI, so no need for a pre-programmed bootloader. just a raw ATmega, straight from the shop.

   Someone seems to have the Arduino IDE running on the Raspberry Pi
   http://raspberrypi.homelabs.org.uk/raspberrypi-the-arduino-development-tool/

   Instead of uploading over USB, it'd need to modify the upload on the R-Pi, to upload programs straight into the ATmega.
   Once loaded the Arduino program could use SPI to communicate with the R-Pi.
   No need for an Arduino USB to serial. Just a 'naked' ATmega. So the board and components would be about £6.

   Posted 11 months ago #
8. 

   crenn
   Moderator

   Well, I can confirm that SPI can successfully communicate with a ATMega168 since it was acting as a port expander essentially. I'll have to look into the Arduino IDE running on the RPi.

   It will definately be interesting if someone can do that! But it would require knowledge of the STK500 proticol.

   Posted 11 months ago #
9. 

   crenn
   Moderator

   I'll just post a quick update here. It's almost 1AM. After finally getting the Pi working with the SD card I had purchased last week for it (was forced to get a monitor for it, and the only monitor with HDMI isn't close, so a 5m HDMI cable was used xD) I'm now ready to start playing around with the Pi and attempting to access the Maple via SPI. Sadly, I'm tired and have things to do in the morning, but updates will occur tomorrow!

   Also, if you get a Pi and the image hasn't been updated yet, look into this thread:
   http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6093

   There is 2 files that need to be replaced to get it working with certain SD cards.

   Posted 11 months ago #
10. 

    crenn
    Moderator

    Today I've gotten the Raspberry Pi and the Leaflabs Maple Mini talking over SPI, I've had a few issues doing it; involving what I believe is cross talk (not too surprising considering the long wires), also the RPi library I'm using makes the SPI pins into input after the program finishes (worked around the problem by using pull-up and pull-down resistors in the Maple) and also working out which has the problem, the program on the RPi or the program on the Maple.

    Either way, the initial test was to just get a byte sent to the Maple from the RPi and then for a byte to be returned from the Maple for the RPi to display. Apart from the cross talk and 'input issues' it wasn't too hard.

    Then I worked on getting the RPi to send a string via SPI to the Maple. I did this with the first byte telling the Maple that this is the 'command' and to expect more data and waits for data to arrive (checking if the CS/NSS pin has gone to the idle position to mark the end of the data transfer) and then outputs the data received via SerialUSB. After I got that working (with some timing issues which are still present), I hooked up an LCD to the Maple Mini and got the text to be output to that as well (and discovered that this LCD module doesn't like running on 3.3V). The program on the Maple will either output a default string, "Hello World", or you can pass a string to the program to get it working.

    I'll have code posted in a couple of hours for both the Maple and the Raspberry Pi.

    Posted 9 months ago #
11. 

    crenn
    Moderator

    Raspberry Pi Code:
    http://www.crennsmind.com/Code/RPi/SPI/spimapleLCD.c
    Maple Mini Code:
    http://www.crennsmind.com/Code/Maple/SPI-Slave/SPI_Slave_LCD.pde

    Enjoy!

    The code will be further commented tomorrow.

    Posted 9 months ago #
12. 

    crenn
    Moderator

    And a light update, this is what it's upto now:
    http://i3.photobucket.com/albums/y81/crenn/Projects/RaspPi/121004/IMG_1812.jpg

    Tomorrow it gets integrated with a robot base.

    Posted 7 months ago #
13. 

    crenn
    Moderator

    It's been a while, but thought I might drop this link of EEVBlog's latest video here as it features my Raspbian Rover and both my Maples.

    http://www.youtube.com/watch?v=zhVpdQPbji0

    Posted 3 months ago #
14. 

    gbulmer
    Moderator

    Presumably folks have noticed that Raspberry-Pi Model A is available, for example:
    http://uk.rs-online.com/web/p/processor-microcontroller-development-kits/7568317/
    http://downloads.element14.com/raspberryPi1.html?isRedirect=true

    It has no Ethernet, only 1 USB, and only 256MB of RAM (vs R-Pi B), But that is a lot of computer for the price.

    Posted 3 months ago #
15. 

    crenn
    Moderator

    Last I heard it was Europe only for the moment, but I have a Model A on the shopping list, should be 1/3rd of the power consumption compared to the Model B.

    Posted 3 months ago #

RSS feed for this topic

Reply

You must log in to post.