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--- projects:picoatlas:picoatlasii [2011/01/29 15:14] – jcoxon
+++ projects:picoatlas:picoatlasii [2011/02/09 18:49] (current) – jcoxon
@@ Line 40: / Line 40: @@
     * Mode 1 - 'Day Mode' - between 0700 and 1900 - the payload will transmit every 20 seconds turning the radio off between to save power - there will be a preamble of UUUU to help dl-fldigi catch the transmission. The GPS will remained power through out this.
     * Mode 2 - 'Night Mode' - between 1900 and 0700 - the payload will transmit 10 strings of data with gaps of 10 seconds and then will shutdown the GPS and radio for 10 minutes. If when the GPS is restarted it has failed to achieve lock it'll continue to tx until it does before shutting down again.
+  * Battery Voltage
+    * 1024 = 4.0v
+    * 1000 = 3.9v
+    * 975 = 3.8v
+    * 950 = 3.7v
+    * 925 = 3.6v
+    * 900 = 3.5v
+    * 875 = 3.4v
+    * 850 = 3.3v
 ===== Jobs =====
   * <del>rebuild 1/4 wave with lighter radials</del>
@@ Line 51: / Line 59: @@
     * <del>Test narcsleep</del>
     * <del>check radio EN</del>
+===== Launch =====
+{{:projects:picoatlas:picoatlas2.jpg|}}
+{{:projects:picoatlas:picoatlas2alt.jpg|}}
+Overall the launch went well, filling the 4 balloons was easy, a pleasant change from worrying about damaging the balloon we were able to put the balloons in the boot of the car while we filled the rest. The payload also worked as planned and so once all was rigged up we released the balloons and payload. The ascent rate was slow but steady and we had good reception from multiple stations - at times up to 12 stations were decoding and uploading the data to the server.
+Just after midday the balloon began to descend at approximately 1m/s and was tracked all the way down to 155m near to Rugby. As this was only an hour away by car I went to recover - arriving in the last known position I could pick up the radio strongly and after decoding the landing spot proceeded only to find it stuck in a high tree. On inspection it was possible to see that one of the balloons had burst and this had resulted in the slow drift down. The payload was too high to recover so I left my number at the local pub and went home, I also emailed some of the local hams. M0NWY kindly went to look the next morning and reported that it wasn't in the tree any longer and I then received a phone call saying that someone had found the balloon as it had come lose and drifted west. I was able to collect the payload in good condition the following Friday.
+==== Lessons ====
+  * The current 36" balloons are not strong enough to super-pressure with the current setup.
+  * The solar panel worked well at maintaining the LiPo charge during daylight hours. It was a shame that we weren't able to get any data the next day as it had blown out of the tree.
+  * The Seeeduino film is just too fragile to use - a Arduino Mini Pro would be tougher and have the same mass.
+  * Gaps between telemetry are fine as long as the pre-amble was present - this increased the success in decoding.
+  * Ublox GPS modules when working are great!