Differences

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--- projects:high_altitude_slug:hardware [2006/06/13 11:08] – phatmonkey
+++ projects:high_altitude_slug:hardware [2008/07/19 23:33] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 ====== Hardware ======
-===== The slug =====
+===== Computer =====
-{{ :projects:high_altitude_slug:linksys_nslu2_board.jpg?200|The Linksys NSLU2}}
+The on-board computer will be a Gumstix Connex with a robostix and netMMC expansions. The robostix can be used for GPIOs, servos and analogue inputs. The robostix provides two TTL level serial ports from the Gumstix for the GPS and phone.
-The on board computer will be a Linksys NSLU2 network storage device (the "slug"), which is a low power, small and cheap 266MHz XScale platform that runs [[wp>Linux]] natively. It has 32MB of SDRAM, 8MB of flash memory (for OS), a network port, two USB 2.0 ports and a serial port.
-[[wp>CompactFlash]] cards connected via USB will be used as a storage medium. They have no moving parts and will survive heavy impacts.
+The netMMC expansion has a network port for development and an MMC card for storage. It probably uses up too much power and space for the final thing, but it'll be great for development.
-We have [[wp>Debian]] Etch running on it slug at the moment.
-It has the [[http://www.nslu2-linux.org/wiki/HowTo/ForcePowerAlwaysOn|force power on modification]], and I will probably remove a resistor to [[http://www.nslu2-linux.org/wiki/HowTo/OverClockTheSlug|de-underclock it]] at some point.
 ===== Navigation =====
-GPS will be used for position and altitude. IR thermopiles will be used to detect the horizon for attitude information.
+GPS will be used for position and altitude. I have a Garmin [[http://www.garmin.com/products/gps25/|GPS-25]]. It is a simple OEM unit, which will reduce weight and size.
-I have a Garmin [http://www.garmin.com/products/gps25/ GPS-25] HVS version (would prefer the LVS one, but this is all I could get off ebay!). It is a no frills OEM unit, which will reduce weight and size.
+IR thermopiles will be used to detect the horizon for attitude information. They measure IR radiation, and since more radiation is emitted from the ground than the sky, the position of the horizon can be calculated. With 6 thermopiles positioned around the glider (2 for each axis), the attitude of the glider can be calculated remarkably accurately.
 ===== Communication =====
-See other parts of the wiki for more information on communication.
+See other parts of the wiki for more information on communication, especially radio.
-We can use the Siemens M20 GSM terminal (or a Nokia 5110 with a serial cable) to send us a text message of the payload's location and status after it has landed. Ideally it would come back to where it was launched, but there may be problems. We can also send text messages to the payload to control it if need be.
-===== I/O =====
-For all I/O tasks, we will use an [[http://www.arduino.cc/|Arduino]] board, which is based around an Atmel chip. It has a built in USB-serial adaptor. It has various analogue inputs and digital in/outputs, which can also produce PWM signals for servos.
+We can use a Nokia 5110 with serial cable to send us a text message of the payload's location and status after it has landed, and maybe put up coordinates on the website using a Siemens M20 GSM terminal.
 ===== Photography =====
 Not a great concern right now. :)