# Smallest altimeter?

### Help Support The Rocketry Forum:

#### TRFfan

##### Well-Known Member
What is the smallest commercial altimeter out there?

#### markkoelsch

##### Well-Known Member
Reading only or also capable of deployment control.

TRF Supporter

Thanks!

#### ksaves2

Smallest DD altimeter there was, was the PicoAlt AD4. It wasn't for the faint of heart to setup and unfortunately I believe is out of production. Kurt

#### dhbarr

##### Amateur Professional
Current smallest DD is the Bear AltiDuo SMT AFAICT.

#### rharshberger

##### Well-Known Member
OP has stated "Reading" not "DD".

#### dave carver

##### ....what hump?
What's the size and altitude capability of the Estes version?

#### rharshberger

##### Well-Known Member
What's the size and altitude capability of the Estes version?

The Estes is 12g, but an number of people I have associated with have had issues getting them to read, something about issues with launch detection. An Jolly Logic Alt3 weighs 10g and is much more reliable. The Adrel Alt-Bmp is the current smallest reading altimeter at 1g a tie with the PicoAlt PICO-P1.

#### dhbarr

##### Amateur Professional

The Estes is 12g, but an number of people I have associated with have had issues getting them to read, something about issues with launch detection. An Jolly Logic Alt3 weighs 10g and is much more reliable. The Adrel Alt-Bmp is the current smallest reading altimeter at 1g a tie with the PicoAlt PICO-P1.
And someone in the US is supposed to start carrying the Adrel, but I can't for the life of me remember who.

#### Todderbert

##### Well-Known Member
If you only need 18mm fit, the firefly is great, onboard lithium battery and weighs in at 3grams total. The others are smaller but you have to add a battery, looks like lipos, not sure if you can fit a lithium cell holder to them.

#### Nytrunner

##### Pop lugs, not drugs
TRF Supporter
If you hold out for a few months, you can order the Altimeter 4 by Jolly Logic. Size of your thumb and a mass of ~ 1g I believe?

When a club member gave me an Alt 2, I was going to get an Alt 3 in the near future, but now I can be patient!

#### BEC

##### Well-Known Member
In this order from smallest currently on the market: Adrel Alt-BMP, Altus Metrum microPeak, PerfectFlite FireFly. The Adrels are currently only available from the maker in Poland (though I have also heard there will be a US dealer identity TBD). The microPeak is also a recording altimeter - 45 seconds of data, which is enough for the up part for most flights along with at least a portion of the down. Then the FireFly....which is inexpensive and fairly easy to find.

Both the microPeak and the FireFly use a small lithium coin cell - in fact they both use the same one. The Adrel requires a separate small li-poly cell (which Adrel also has available) and a means to charge it (also available from Adrel, among others). A separate interface is required to download the data from the microPeak. Versions of the interface software are available for Windows, Mac OS and Linux. The microPeak's LED is much easier to see in the sun.

Here is a quick iPhone picture of FF and mP. I don't have an example of the current Adrel device, just older ones. They are about 2/3 the size of the microPeak not counting the separate li-poly cell.

I am looking forward to AltimeterFour, which is gong to be certainly in the same size class but have some clever features I am sure.

#### Micromeister

##### Micro Craftman/ClusterNut
TRF Supporter
The Alt-LED & Alt-BMP from Adrel are by far the smallest read only altimeter out there. I don't have the Alt-BMP which is slightly smaller then the Alt-LED shown below is the one ALL the international team member now use. the Alt-LED easily fits in a T4 (.448") Body tube. and is powered by the smallest 3.7v 20mah Lipo package i've seen. The Newer Alt-BMP is smaller yet using the same Lipo package.

Last edited:

#### Gus

##### Well-Known Member
Top to bottom:

Micropeak
Perfectflite Firefly
Perfectflite Pnut (older version)
Jolly Logic Altimeter Two
Jolly Logic Altimeter Three

#### dhbarr

##### Amateur Professional
Top to bottom:

Perfectflite Firefly
MicroPeak
Perfectflite Pnut (older version)
Jolly Logic Altimeter Two
Jolly Logic Altimeter Three
Firefly & MicroPeak are backwards?

#### John Beans

##### Founder, Jolly Logic
TRF Supporter
Details I shared at NARCON:

1. AltimeterFour can fit in a 10mm tube. About 1 gram.
2. It has a built-in rechargeable battery.
3. It is fully enclosed, and can be flown in rockets without a payload section.
4. It can do full flight analysis (it has both a barometric pressure sensor as well as a 100G 3-axis accelerometer), so it can perform the same flight analyses as AltimeterTwo and AltimeterThree.
5. It's designed to be as easy to use as our other altimeters.

No set release date yet. "This year."

BDB

#### Leo

##### Well-Known Member
John, that will be an amazing altimeter!

#### dhbarr

##### Amateur Professional
Details I shared at NARCON:

1. AltimeterFour can fit in a 10mm tube. About 1 gram.
2. It has a built-in rechargeable battery.
3. It is fully enclosed, and can be flown in rockets without a payload section.
4. It can do full flight analysis (it has both a barometric pressure sensor as well as a 100G 3-axis accelerometer), so it can perform the same flight analyses as AltimeterTwo and AltimeterThree.
5. It's designed to be as easy to use as our other altimeters.

No set release date yet. "This year."

View attachment 314612
My prediction: released right after my last flight of the season, so it stares at me all winter. Curse your beautiful products! ^_^

#### BEC

##### Well-Known Member
Firefly & MicroPeak are backwards?
Sure looks like it to me.....

That Adrel BMP is tiny....now the LiPoly cell is what sizes the tube it fits in.

Wow, John - AltimeterFour sounds like it will be amazing. And at 1g with power it will be the lightest of the bunch at about 60% of the microPeak.

#### dhbarr

##### Amateur Professional
Details I shared at NARCON:

1. AltimeterFour can fit in a 10mm tube. About 1 gram.
2. It has a built-in rechargeable battery.
3. It is fully enclosed, and can be flown in rockets without a payload section.
4. It can do full flight analysis (it has both a barometric pressure sensor as well as a 100G 3-axis accelerometer), so it can perform the same flight analyses as AltimeterTwo and AltimeterThree.
5. It's designed to be as easy to use as our other altimeters.

No set release date yet. "This year."

View attachment 314612
Can I order my Christmas present yet?

TRF Supporter

#### snrkl

##### Well-Known Member
TRF Supporter
Details I shared at NARCON:

1. AltimeterFour can fit in a 10mm tube. About 1 gram.
2. It has a built-in rechargeable battery.
3. It is fully enclosed, and can be flown in rockets without a payload section.
4. It can do full flight analysis (it has both a barometric pressure sensor as well as a 100G 3-axis accelerometer), so it can perform the same flight analyses as AltimeterTwo and AltimeterThree.
5. It's designed to be as easy to use as our other altimeters.

No set release date yet. "This year."

View attachment 314612

Being that small, I'm worried I would lose it!!!

#### blackbrandt

##### That Darn College Student
Details I shared at NARCON:

1. AltimeterFour can fit in a 10mm tube. About 1 gram.
2. It has a built-in rechargeable battery.
3. It is fully enclosed, and can be flown in rockets without a payload section.
4. It can do full flight analysis (it has both a barometric pressure sensor as well as a 100G 3-axis accelerometer), so it can perform the same flight analyses as AltimeterTwo and AltimeterThree.
5. It's designed to be as easy to use as our other altimeters.

No set release date yet. "This year."

View attachment 314612

At the rate this is going, the AltimeterFive will be the size of a grain of rice and put itself in the rocket for you....

#### dhbarr

##### Amateur Professional
Altimeter Six will just be a bag of powder you waft at your bird ^_^

#### TNmike

##### Well-Known Member
John, any hint as to the price of the AltimeterFour? Sounds like it's going to be an awesome product.

#### John Beans

##### Founder, Jolly Logic
TRF Supporter
John, any hint as to the price of the AltimeterFour? Sounds like it's going to be an awesome product.
AltimeterFour comes in two pieces. The tiny part you fly&#8212;and might lose or break&#8212;will be our least expensive. The overall price isn't set yet.