Air Data Instrument

Posted February 22, 2014

The Dangerpants Labs Air Data Instrument (ADI) is an open-source, AVR-based device which utilizes the Arduino bootloader and libraries to provide the user with the current airspeed, altitude, vertical speed, and time of day in a small, lightweight, power-efficient package.

It uses a Bosch BMP085 or BMP180 to determine altitude and vertical speed, a Maxim DS1307 real-time clock, and a Freescale MPXV5004DP differential pressure sensor for airspeed. The processor is an Atmel ATMega328P. An HD44780-compatible 16x2 LCD display shows the data.

Plans for the ADI are available here, in the Downloads section. A user manual and construction guide are available in the Documentation section.

The latest versions are as follows:

  • Firmware: 1.0
  • PCB: 1.3

The Dangerpants Labs Air Data Instrument, including source code, schematic, PCB design, documentation and Eagle files, is licensed under the Creative Commons BY-NC-SA 4.0 license. It is intended to be free for anyone to use for any non-commercial purpose they see fit, pursuant to the disclaimer. Please credit Laura Johnston or Dangerpants Labs.

Creative Commons License
The Dangerpants Labs Air Data Instrument by Laura Johnston is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

ADI News

SMT Version Coming July 7, 2014

I've finally started work on a surface-mount version of the ADI, and the goal (which looks quite achievable) is to fit it all in the same footprint as the LCD, allowing them to be mounted to each other. This will simplify interfacing considerably, and the SMT version will have the SET, PLUS and MINUS buttons built onto the board. I'll post more as I make progress.

Construction Guide Underway February 21, 2014

I have finally made an honest start on the long-promised Construction Guide. Pictures are still in the works, but at least the text is there.

New Website February 19, 2014

The Air Data Instrument has a new website, which is a huge improvement over the old one. Information is easier to find, it's easier to read, and it actually uses HTML standards newer than 1997.

New PCB Design January 20, 2014

The Bosch BMP085 has been discontinued, and the BMP180, which replaces it, has a different physical footprint. Bosch says the new chip is program-compatible with the old one, so you should be able to load the current ADI firmware with the new board and it should Just Work.

Because there are still BMP085s out there, I will leave two board designs active (purchase links take you to OSH Park; I do not receive any money from board sales):

  • v1.3 (Purchase): The current design, which works with the BMP180
  • v1.2 (Purchase): The current design, which works with the BMP085


Important Disclaimer

The Dangerpants Labs Air Data Instrument is not for use in aircraft! Please read the full disclaimer. Once you have read and agree with the disclaimer, click below:


v1.0: adi-firmware-v1.0.tar.gz

PCB and Schematic (Eagle)

v1.2: adi-eagle-v1.2.tar.gz (for use with BMP085) (Purchase PCB)

v1.3: adi-eagle-v1.3.tar.gz (for use with BMP180) (Purchase PCB)


Bill of Materials - A list of parts necessary to build the Air Data instrument

Construction Guide - Information on building your own ADI

User's Guide - This document describes how to use the Air Data Instrument once it's been constructed and installed

Specifications - The ADI's physical and software specifications

Dangerpants Labs ADI Disclaimer

The short version

Don't sue me. This thing has never been tested for use in an airplane, and is absolutely unsuitable as a flight information source. It's a toy. Don't get yourself killed pretending it's not.

The real version

The Dangerpants Labs Air Data Instrument (ADI) is a novelty instrument, designed and constructed by an untrained, hobbyist electrical engineer for use as a novelty. As such it is specifically NOT INTENDED FOR USE ON AIRCRAFT or IN ANY SITUATION WHERE HUMAN LIFE MAY BE JEOPARDIZED BY ITS USE.

The ADI is not offered as a kit or as a completed product, only as a set of plans, available for free via

The ADI has never been tested for accuracy or reliability. It was not designed with any purpose other than as a novelty. Although it claims to report altitude, airspeed and vertical speed, no attempt has been made to verify the accuracy of this data. No attempt has been made to ensure the device will work as described.

Federal Aviation Regulations control the installation of equipment in any certificated (non-experimental) aircraft. The FARs specifically prohibit the installation of uncertified flight instruments, such as the Dangerpants Labs ADI, in certificated aircraft. You risk license suspension or revocation, fines and/or prison time if you violate the FARs.

By building this device, you agree that it is only to be used as a NOVELTY, and will UNDER NO CIRCUMSTANCES BE USED AS A PRIMARY FLIGHT INFORMATION DISPLAY. By building a copy of the Dangerpants Labs ADI, you assume ALL RESPONSIBILITY for its use, as well as agreeing to INDEMNIFY and HOLD HARMLESS Dangerpants Labs, also known as Laura Johnston. This agreement shall be binding upon all heirs and assigns.

If you don't agree to any of these terms, do not build, install, or purchase an ADI.