From 00acebec05cf489b9bda13d4a084897b2e4b91f0 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Fri, 9 Apr 2010 02:07:32 -0600 Subject: [PATCH] report initial v1.0 TM success --- .../posts/TeleMetrum_v1.0_Boards_Arrive.mdwn | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 bdale/blog/posts/TeleMetrum_v1.0_Boards_Arrive.mdwn diff --git a/bdale/blog/posts/TeleMetrum_v1.0_Boards_Arrive.mdwn b/bdale/blog/posts/TeleMetrum_v1.0_Boards_Arrive.mdwn new file mode 100644 index 0000000..ee3b858 --- /dev/null +++ b/bdale/blog/posts/TeleMetrum_v1.0_Boards_Arrive.mdwn @@ -0,0 +1,26 @@ +[[!tag tags/rockets]] +The first production run of [TeleMetrum](http://altusmetrum.org/TeleMetrum) +boards arrived from our assembler today, and overall things are looking good! + +Unfortunately, I specified the wrong value for a capacitor associated +with the new and improved 150mA 3.3 volt regulator. The resulting symptom +was interesting to debug... everyting seemed to be fine except that the GPS +chip wouldn't talk to us. After some investigation, it became clear that +the 3.3 volt power +supply was taking much longer to stabilize than it should... long enough that +the power-on reset circuit was relaxing before the supply was stable! The +cc1111 apparently handles this just fine, but the GPS chip doesn't. Since +the new cap is optional, just removing it caused everything on the +first test board to +start working! The ultimate solution will probably be to both replace the +new bypass capacitor with one of the correct value, and to swap out the cap +in the reset circuit for a somewhat larger value to ensure we have plenty +of margin in the reset circuit. + +I now have 4 of the new boards completed, turned on, and passing initial +tests. Hopefully tomorrow I'll be able to wrap up the rest of the required +functional testing. I then need to focus my attention on a business trip +all of next week... but if all keeps going well, we're *very* close to +taking our first orders. + +Stay tuned! -- 2.30.2