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--- projects:picoatlas:picoatlasvi [2012/05/14 07:24] – jcoxon
+++ projects:picoatlas:picoatlasvi [2012/07/06 06:46] (current) – jcoxon
@@ Line 167: / Line 167: @@
   * Currently the GPS only uses ECO mode rather than power saving mode as its more reliable
-==== Status ====
+==== Components ====
+  * Arduino Mini Pro 3.3v 8Mhz
+  * RFM22b Radio
+  * Ublox 6 GPS on a Pico board with chip antenna
+  * Lipower Step Up board
+  * 2xAAA in parallel soldered
+  * Single layer of bubble wrap + tape
+  * 1x 92cm foil balloon
+  * Helium
-/05/12 - //waiting for some time off and better weather - payload complete//
+==== Flight ====
+Picoatlas 6 MK 4 had been ready for a number of months to fly, on a spur of the moment decision in an evening when the weather was perfect for launch (very little ground wind) it was decided to fly. The launch was from the North Kent coast with winds blowing directly north. Completed the payload weighed 29grams with an additional 2grams of lift aiming for a 1m/s ascent rate roughly (once inflated the ascent rate was measured and the helium volume altered). Simple launch the flight was picked up relatively quickly and travelled north over East Anglia. As planned at 2300 UTC it switched from continuous RTTY to slow-hell however due to a bug in the code it didn't update its coordinates. It continued to fly overnight floating at 4500m and when it switched back to RTTY at 0700 UTC was near Newcastle. It continued to be tracked during the day all the way to just north of Dundee when the batteries ran out and the signal was lost. The float was at that time at 5500m and was relatively stable - it seemed like it would have carried on floating if only we could have continued to track it.
+{{:projects:picoatlas:picoatlas6flight.jpeg?300|}}{{:projects:picoatlas:picoatlasalt.jpg|}}
+==== Conclusions ====
+  * Excellent flight, Pico payloads really can do long duration flights, the key points to achieving this are:
+    * Single balloon (therefore need ultralight payloads)
+    * Launch on calm days, winds need to be < 5mph to allow you to safely get the balloon in the air
+    * Aim for an ascent rate of 1m/s to achieve float.
+  * Payload worked very well, there were a few bugs (the time for RTTY switching weren't perfect, code now changed to switch back to RTTY slightly earlier, also the bug where slow-hell didn't give lat/lon/alt has been fixed).
+  * Slow-hell doesn't really work, its just too tedious to transcribe the data manually though its an awesome protocol.
+  * Measuring arduino internal temp is a waste of time as it generates its own heat
+==== Improvements ====
+  * Switch to using the temperature sensor onboard the rfm22b
+  * Stop using slow-hell and instead use periodic RTTY at night
+  * Continue to improve power saving
+  * Add lightweight solar panels to help power during the day
+  * Use a complete PCB instead of wiring together as it will save additional mass