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Ed Kalin's All-Sky Camera Blog

April 2014 Previous month
Things have been pretty quiet for me on the blogging front for the last week, but I have a good excuse.   I have been getting ready to show off my work-in-progress all-sky camera (two of them, actually) at the Westport (CT) Mini Maker Faire, scheduled for Saturday, April 26. The Faire was sponsored by the Westport Library, the same organization that had sponsored my month-long stint as "Maker in Residence", and so I was sure to find plenty of interest in seeing my progress in building the ...
I'm installing pyFirmata on the Pi to communicate with the StandardFirmata sketch on the Gertduino.   I had already installed the pySerial library a couple of blog posts ago in order to enable the program-to-program sample code that I tested. So I can skip that step now and go directly to installing pyFirmata.   But I do need to install git in order to git pyFirmata. Some folks (for example, the author of the MagPi article referenced previously) install pyFirmata by using mercurial t ...
Firmata is a serial communication protocol designed for transferring data between (for example) a microcontroller board and a host computer. Software running on the host (the Pi, in this case) can control, either by reading or writing to, ports on the target microcontroller (the Arduino, in this case).   There are a couple of different approaches typically adopted by Firmata users. One is to use a pre-written Arduino sketch called 'StandardFirmata' to handle the Arduino's ports, and the ho ...
Slowly but surely I've been plodding through my phased approach to testing communication between the Pi and the Gertduino via the serial port. So far it has been delightfully drama-free.   It took just a few minutes of effort to load and run the complementary sample Python (PiGertduinoSerial.py) and Arduino (PiGertduinoSerial.ino) programs shown at the bottom of the page at http://friendsoftheunicorn.net/content/raspberry-pi-gertduino-serial   I downloaded both sample programs, scann ...
Yes indeed, I'm super serial right now. Or is that supposed to be 'super cereal'? I carefully followed the instructions for disabling login via the Pi's serial port. Then I disabled the Pi's boot messages (out to the serial port), shut down the system, set the jumpers to connect the Pi's serial transmit line to the Gertduino's serial receive line (and vice-versa), powered up the system (it booted up just fine, yay!), installed the minicom terminal emulator, installed the scrot screen capture ...
Where I last left off, Major Tom and I had just encountered some Schmitt trigger hex inverter input pins floating in a most peculiar way.  I'm pretty sure that I've got that part sorted, and now I'm off to try out some bigger and better things.   Now, I have to admit that I enjoy loading programs into the Arduino IDE on the Pi and then compiling and uploading them to and running them on the Gertduino as much as any other microcontroller enthusiast, but after all that's not the main re ...
In my last post I had just discovered a version of the Gertduino manual that includes a schematic diagram. It turns out that that version of the manual (http://www.farnell.com/datasheets/1778121.pdf) is "version 1.3 Dated 6th Nov 2013", whereas the version without the schematic, pointed to by the element14 Gertduino page at http://www.element14.com/community/docs/DOC-64326/l/gertduino-add-on-board-for-raspberry-pi#anchor3 is "version 1.4 Dated 6th Nov 2013" (http://www.element14.com/community/se ...
With all of the fuss and bother involved in swapping jumpers and rebooting, I had forgotten that one of the first things that I accomplished by following the Gertduino setup instructions (both the instructions in the Gertduino manual and on the Friends of the Unicorn site) was to install the Arduino IDE. The key to doing that is following the link to a more complete set of instructions at https://projects.drogon.net/raspberry-pi/gertboard/arduino-ide-installation-isp/   There is another pa ...
Back to setting up the Gertduino.   Where was I? Ah, yes. When we last visited, I had just managed to successfully reboot the Pi with the Gertduino onboard, after moving one of the programming jumpers.   It looks like the instructions at http://friendsoftheunicorn.net/content/gertduino-setup set up the ATmega48 first and then do the same for the ATMega328P, whereas the instructions at https://projects.drogon.net/raspberry-pi/gertduino/atmega-setup/ do it in the opposite order, a crit ...
I am now the proud owner of a CR1025 lithium cell, destined to be the real-time clock backup battery for my new Gertduino board.   Note that I did not say that I'm the proud owner of five CR1025 lithium cells - so far I have not yet received my pack of five batteries ordered via Amazon (but that may be an 'own goal', as I currently have mail and packages addressed to my home automatically re-routed by the USPS to my PO Box, which can add days to the normal shipping time). So, instead of wa ...
I am grateful to have been chosen to do a 'road test' of the Gertduino add-on board for the Raspberry Pi.   My plan for the Gertduino is to use it to enhance a Pi project that I've been working on. I am developing an experimental all-sky camera based on the Raspberry Pi and the Pi camera module. In my blogging here, I will be focusing on the unique features of the Gertduino and how they are helping me to achieve my goals for the all-sky camera project. Note, however, that I am also regular ...