avatar

MikeGrusin

Member Since: May 20, 2010

Country: United States

Profile

Role

Rocket Scientist

Spoken Languages

English, Klingon

Programming Languages

Whatever best gets the job done, usually C. My favorite language was Modula-2 (look it up).

Universities

WPI, CU Boulder. Degrees in aerospace engineering and computer science.

Expertise

Spacecraft systems engineering, embedded systems engineering, low-level firmware, 3D graphics and animation, and troubleshooting (but real trouble shoots back).

Interests

Hacking (the good kind), scuba diving, dumpster-diving for obsolete hardware, anything that flies (from bees to the Space Shuttle), birdwatching, sending stuff into orbit and beyond.

Websites

www.flyingcircuits.com

Sweeping legal changes are afoot that could change the hobbyist airspace for years to come. Your input can make a difference.

Continue reading

CubeSats will soon be traveling beyond LEO, and are available in a new compact size. We check in with the people pushing the limits.

Continue reading

On April 5th, teams from around Colorado will try out their miniature Mars rovers in the Great Sand Dunes.

Continue reading

How to handle the child for whom disassembling their toys is more fun than actually playing with them.

Continue reading

SparkFun returns to the AIAA Small Satellite Conference with more people, more stuff, and export-controlled sombreros.

Continue reading

What did you do on your summer vacation? These students are launching experiments on government sounding rockets.

Continue reading

You've just finished your new project. Before you apply power, here are a few tips to keep the smoke in.

Continue reading

Mike and Pete take a road trip to an innovative aerospace conference to find out more about the final frontier for amateur spacecraft makers

Continue reading

Rock-climbing researchers use clever dataloggers to solve a migration mystery and help save a species.

Continue reading

Your Personal Black Box

Inexpensive sensors and storage are giving us the ability to record our lives, revisit the past, and sometimes solve mysteries.

Continue reading

Sam Berrada dropped by to show off the sign language to speech system he designed. Did we mention he's in the 8th grade?

Continue reading

Cackling Apple Head Witch

October 30, 2014

Make your own cackling apple head witch to scare all of the trick or treaters this Halloween!

LTC4150 Coulomb Counter Hookup Guide

September 18, 2014

A "Coulomb Counter" is like a gas gauge for your battery. Here's how to use it.

BMP180 Barometric Pressure Sensor Hookup

January 9, 2014

The BMP180 is a barometric pressure sensor, this tutorial tells you how to use it.

TSL2561 Luminosity Sensor Hookup Guide

December 27, 2013

The TSL2561 is an light sensor that's very inexpensive for the accuracy it provides. Here's how to use it.

Getting Started with the LilyPad MP3 Player

May 8, 2013

The LilyPad MP3 Player is an amazing little board that contains almost everything you need to play audio files. You can use it to create all kinds of noisy projects, from MP3 hoodies to talking teddy bears. Your imagination is the only limit! This tutorial will help you get started.

What is a Circuit?

February 6, 2013

Every electrical project starts with a circuit. Don't know what a circuit is? We're here to help.

Serial Peripheral Interface (SPI)

January 14, 2013

SPI is commonly used to connect microcontrollers to peripherals such as sensors, shift registers, and SD cards.
  • That’s a great question. The allophones in the SpeakJet are fixed, so unfortunately you can’t change them. They were presumably chosen primarily to accommodate the English language, but because they cover a wide variety of individual sounds, I don’t see why you couldn’t form reasonably understandable Spanish or other languages with them. I just googled and didn’t immediately find any Spanish SpeakJet dictionaries, so it would take some work - for each word you’d need to look through the list of allophones and play with the grouping to perfect the pronunciation, and it may fall short with certain words or complex languages. But if you have a limited number of voice messages you need to formulate I think it’s doable. Good luck and let us know how it goes!

  • Note that like all pressure sensors, the BMP180 outputs absolute pressure while NOAA reports relative pressure. What’s the difference? Relative pressure that you get from weather reports is always altitude-compensated so that you can directly compare weather data between e.g. San Francisco and Denver without always having to take the altitude difference into account (the absolute pressure in Denver is ¾ of that in San Francisco, but the relative pressure makes it look like both of them are at sea level). To get relative pressure from your sensor, edit the “SFE_BMP180_example” code and put your current altitude in meters at line 73. The code will then give you pressure that you can compare to weather reports. Note also that taking any pressure reading indoors will almost certainly be wrong due to building pressurization from HVAC systems etc.

    Determining altitude from the sensor is also tricky because it will vary depending on any weather systems moving through at the moment. Your best bet is to take a baseline reading in your code; after that, when you move the sensor up or down, you will get a relative altitude difference from the baseline. The altitude example does exactly this. The accuracy of this decreases over time due to changes in the weather.

    Definitely read through the BMP180 hookup guide, especially the “measuring weather and altitude” section.

  • Yes. TinyGPS and TinyGPS++ are both excellent.

  • The last time I checked, the sdfat library that the example software uses could handle cards up to 32GB.

  • That’s very cool, Thanks for digging into the docs!

  • Classic Nick.

  • We’re really impressed with RockBLOCK which is why we’re carrying them, but there are other options: Many HAB projects use SPOT transmitters. However, SPOT will only transmit location data every 10 minutes, has lat/lon but not altitude (this has caused us big problems in the past), and does not let you send user-defined data. Globalstar has the STX3 module which is similar to the RockBLOCK but is smaller and transmit-only. Globalstar has good land coverage but is missing ocean coverage. There are also APRS systems that work very well, but require an amateur radio license.

  • These are primarily designed to have one unit on your remote platform/vehicle/etc, and use the internet to get messages to and from it. I believe (but may be wrong) that to get a message from one RockBLOCK to another, you’d have to have something watching the web interface to receive the message from one unit, and then retransmit the message to the other unit (which would cost you an additional message). In the majority of cases it’s probably simplest to have your raspberry pi / arduino attached to the internet, and get messages to/from a single RockBLOCK using the web interface.

  • Close. The COCOM limits are 1000 knots velocity or 60,000' altitude. To prevent their use in weaponry, commercial GPS units shut down when one or both of those is exceeded.

    The loophole is that some manufacturers will shut down when one of those is exceeded, and some will shut down when both are exceeded. The latter ones are valuable for HAB use, because they will work above 60,000' as long as you’re not also going faster than 1000 knots (1200MPH). We’ve used our Venus GPS units on balloon flights to 120,000' without problems.

  • This one has the antenna built-in. You could place the whole module in a good spot and run the three wires to it, or consider a GPS receiver like the Venus which has a connector for an external antenna.