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All I know is that the "good fix" flag in the $GPRMC message was false. However the GPS never required rebooting - once the glider landed, the fixes were good. I've got a new model of the PA6 GPS (PA6C) that I put on a board this winter - it is _much_ more sensitive than the older one (gets a...

That's exactly how I've been doing it so far, except I use bench power supplies instead of a dedicated charger. I used to have a dedicated RC charger and never used it - it was just easier to use the power supplies I had on the workbench. I eventually sold it on eBay in a fit of anti-clutter.

OK, I've given up on the idea of running the system off a single Li+ cell. I found a part that would supply enough current (the MAX1709), but it needs lots of low-ESR capacitors and the solution ends up taking up almost half my board space. So I conclude that's not a good solution. So -...

A cheap 2S balancing charger is only $10 or so. Buy an RC plane or heli that uses 2S and you get one for free :) I know how to charge it... https://nerdfever.com/?p=896 But charging 2 batteries is twice as much work as charging one. (And I'm a perfectionist, which is the real reason.)...

That's kind of where I am. At first I thought it'd be nice to use 1S, but it started to look more complicated than I expected. I'm hoping somebody out there will say "Oh, that's easy....". I guess an alternative is to find a way to charge both cells off the 5v USB input. But that looks...

As Boris said above, I'm laying out a new version of the PCB that will be narrower to fit in the 2.6" body tube. Another change I'd like to make is to use a single LiIon cell for power (instead of 2 in series now). One cell would be lighter, and much easier to charge (no balancing issues). I...

I'm not sure what you mean by "pitching over". It was a windy day so there was some weathercocking off the pad, which led to a non-vertical ascent. There were high Gs until motor burnout of course, but after that the rocket coasted to apogee at 0 Gs, not counting air resistance. (Or you could...

As Boris said above, the Autonomy glider is no more. On the first flight I was optimistic that navigation would work - I'd swapped the GPS unit with another one that I'd flown in rockets before (under a parachute) and which worked fine there. We flew it first on a ProX G125 because the day was...

This is what I was told (pasted from their email): I couldn't find it in the the manual, either, and asked about it - they said:

I corresponded with the GlobalTop (GPS maker) people today. It turns out there is a dynamics setting in the GPS chipset I didn't know about - I'm going to check how this was set (didn't have a chance to do that yet). That might be the cause of the GPS dropouts in flight. I also ordered some...

I don't think that's it. The ITAR limits (what that thread is talking about) are 1000 knots and 60,000 feet altitude. The glider gets nowhere near either limit.

It's the GlobalTop PA6B, based on the MediaTek MT3329 chipset. I buy them directly from GlobalTop in Taipei. They've been pretty responsive about questions in the past, so I'm optimistic about getting an answer.

Here are the videos from the 4 flights on Saturday. All 4 flights resulted in nice glides; the software tweaks seemed to help a lot. Ascent was nice and vertical, the yaw over-control problem seems in hand now. Unfortunately, a first look at the logged data shows that the GPS signal dropped...

Thanks! I'll try to prototype it over the weekend and see if it works better. Cheers, --Dave

Hi Adrian, Thanks again for your suggestions - you are much more knowledgeable about this than me! It's true the electronics hardly draw anything compared to the servos (and radio), but the servos only need to run during flight (and then in bursts), while the electronics run the whole time...

Thanks for the suggestions. I'm using a DC-DC converter (Microchip TC105) to get 3.3v from the 7.4v battery (2 x LiIon); I'm sure that contributes some of the noise, but the noise isn't bad when the servos and radios are idle. I don't want to go back to a linear regulator because it wastes...

I've made the following adjustments to the glider for the next flight: Reduced parachute deployment altitude from 60 m (200' AGL) to 45 m (150’ AGL) to get more glide time. Reduced YAW_FACTOR from 1.0 to 0.1 (100 to 10) to make it less sensitive. This makes the servo response less...

We got in 3 flights yesterday. Only one of them was really good, but we learned a lot from all 3; and the glider is in good shape. We decided to name it the "Autonomy". Our goal for the day was to get some flight information about the proper pitch setting for a nice stable glide. There is...

I ran some ground tests of the ejection system today (see video below). It turns out that the parachute has to be packed in a specific way to deploy reliably, otherwise it stays stuck in the hollow nose cone. That happened on the first couple of tests (at 100 and 200 mg of BP). When I...

Um, yes. Less/More and On/Off. What else could you possibly need? (For those who are mystified; see the photo at the bottom of this post.) Cheers, --Dave