Brief:
The PicoAlt PICO-P1 altimeter is what I would consider to be the "thong bikini" of rocketry altimeters. I say that because it's micro-mini small and it barely covers the necessities. Don't sneeze with it laying around or drop it because you might never see it again--especially at the field! Seriously though, the PICO-P1 is a barometric peak reporting altimeter (no data logging or deployment capabilities) that can be used in almost any sized rocket, from MMX on up!

Construction:
I ordered the Pico-P1 directly from the PicoAlt website. Future purchasers be warned that there is a 2-3 week delivery time for all PicoAlt products as they are built and tested for each order. Along with the altimeter, I also purchased the dual 2032 battery holder and a pair of 2032 lithium cells. A single diode was included with the battery holder as well (more on that later). The small USPS box felt empty although I could hear a something softly rattling around. A Ziploc baggy had a copy of the instruction manual and all of the items listed above. However, even the instructions were reduced down onto half pages of paper so there's nothing big about PicoAlt products!

Thumbing through the sparce but adequate instructions, I knew that I was going to need to do some engineering before I was going to be able to use it in a rocket. Opening the anti-static bags with the altimeter and battery holder made that only more obvious as there was nothing to clearly hook these items together without some hardware and soldering. There are no wires or terminals coming off the altimeter, nor on the battery holder. I should also mention that it will almost certainly be the battery/batteries supplying power for the altimeter that will be the limiting factor to how small a rocket you can put the PICO-P1 in. Using larger, more common batteries (and battery holders) will far and away outweigh this tiny device. Finding a method of using low power easily accessible watch or hearing aid batteries are ample enough--it is coming up with a method of connecting them that will perhaps be the greatest obstacle to putting this altimeter in a rocket...

So in my efforts to design a method of easily and securely retaining the 2032 batteries that I ordered with the altimeter, I managed to break the holder. I resorted to taking a trip to my local Radio Shack a visit where I picked up a "N" battery holder (270-405A) and a 6V alkaline battery (23-469). The battery is just a hair on the short side and a little bigger around than a N battery, but it's nothing a little trimming of the battery holder with a X-Acto knife couldn't take care of. From there, I soldered the diode (to reduce the circuit's voltage to something closer to 5V) and the holder's wires to the PICO-P1. Lastly, I glued (using CA) the battery holder to a popcicle stick so that the entire assembly could quite easily be tucked into a BT-20. (I didn't have any BT-5 to see if it would fit in one, but I bet it'd be close if it didn't fit!) The battery and wires were then wrapped tightly with masking tape so nothing could come loose during flight.

While this method of mounting the PICO-P1 works, I'll almost certainly continue to tweak it in the future so that it's more sturdy yet as adaptable for use in as many of my rockets as possible.

Construction Rating: 3 out of 5

Flight:
The first two test flights were done with my US Rockets Banshee and AeroTech F52-8T reloads for the 29/40-120 hardware. However, in my haste preparing for the launch, I neglected to bring something lightweight to stuff into the large payload bay to prevent the altimeter from get bounced around all over the place. Ingenuity kicked in as I looked through my vehicle and I discovered my son's diaper bag. I chuckled at the thought of using a (clean!) diaper to stuff down into the tube. Pushing it down with a long dowel, I was confident that it would work as well as if not better than the foam I had intended on bringing to do the job. So with breezy but clear February skies at a club launch, I sent the PICO-P1 upward.

I'm glad I did two flights as the first one resulted in a bogus reading of 60ft. That's no typo--sixty feet. My Banshee ain't afraid of heights as there was no doubt it went much, much higher than what the altimeter reported. Looking over the battery holder, I concluded that the battery must have shifted enough downward when the rocket was under thrust to lose contact with the terminal. I made sure to put the altimeter back in upside-down from the first flight to reverse the effect--or at least give the battery a better chance of staying put.

The second flight result was significantly better: 1,279ft. That looked to be very much in the ballpark to my eye!

So as long as I have my altimeter mounted so that the battery is forced into contact with the terminal, I can expect to get back accurate data. I should also mention that a really cool feature of the PICO-P1 is that the previous flight data is stored indefinitely without power going to it. That is why I was able to get a readout of the first flight's (albeit incorrect) data--it reported the data up to the point where it lost power (and in turn will report the second flight's data the next time I use it in the future!) Then once the unit cycles power, it takes a full minute to get a stable, reliable reading of ground level and therefore did not get any data from the remainder of the flight (as the rocket was well on its way back down after 60 seconds thus preventing it from getting a good reading once power was restored).

Flight Rating: 4 out of 5

Summary:
For such a small device, construction demands, and minimal documentation, I would not recommend the PICO-P1 for someone looking for their first altimeter (at least not without help from someone who has owned/used one). A basic understanding of electronics and a familiarity with soldering would be minimal requirements for using one of these altimeters. Despite these shortcomings, the PicoAlt PICO-P1 is an excellent device that will allow you to track the peak altitude of all of your rockets no matter how small!

Overall Rating: 4 out of 5