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 regularly blogging about the trials and tribulations involved with building not just one, but three different all-sky camera designs. You can follow my other blog at: allskycamera | Developing an experimental All-Sky Camera based on the Raspberry Pi microcomputer board
An all-sky camera is a digital camera that can capture photographs or videos of the entire arc of the sky within a single frame. Such a camera could be used to record meteor or satellite trails, time-lapse cloud motion sequences, migrating flocks of birds, aircraft (or perhaps even UFOs!) criss-crossing the sky, weather events, the motion of astronomical features such as the sun, moon, planets and stars, and more. The all-sky Camera can be used for performing scientific observations, exploration and learning (in areas such as astronomy, weather and photography) as well as for aesthetic pursuits (such as nature appreciation and artistic expression).
My plan for developing the all-sky camera includes the need to do various types of data collection and monitoring via the Pi's GPIO port. While I had been considering building my own Arduino clone to connect to the Pi and handle the low-level interfacing tasks, it occurred to me that the Gertduino already has onboard facilities that would handle my needs. For example, the Gertduino already has a battery-backed realtime clock as well as signal conditioning to convert between 3.3 volt and 5 volt signals. The Gertduino will let me use the ATmega328's analog inputs for certain sensing tasks that I will need (for monitoring parameters both inside and outside of the camera housing, such as temperature and humidity values, battery voltage, and discharge rate). I will also make use of the expansion shield headers for interfacing a GPS receiver module (to record the precise camera location), an electronic compass module (for displaying a true north indicator in each camera frame), and possibly also for controlling a heater (to prevent condensation from forming inside the camera housing). In addition, while I had not previously contemplated doing such a thing, it appears to me that the Gertduino's on-board IRDA interface might permit me to experiment with making an Android tablet-based camera control panel or data/status monitor.
I've already had a bit of an adventure trying to locate a lithium coin cell, a CR1025, to power the Gertduino's built-in RTC. I couldn't find the battery at a local Home Depot store, nor could I find it at a CVS pharmacy. However my third attempt led me to visit Radio Shack, and yes, indeed, they do carry the CR1025, however they want $6.00 for a single battery. I can get a card holding five of the exact same battery from Amazon for less than that, including shipping. So I ordered them from Amazon, and will be heading down to check my post office box this afternoon to see whether it has arrived yet. The RTC is key for my application because recording the date and time when each photo was taken is necessary. I expect to operate the all-sky camera in locations where I do not have an active network connection and will therefore be unable to sync the Pi's clock over the network. So one of the first tasks that I plan to accomplish with the Gertduino is to integrate the RTC.
Stay tuned for more...