Astronomy AltAz calculator

pbhuter

I have been using an app on my phone to measure altitude/azimuth (AltAz) for astronomy and astrophotography, but I really do not think it is all that great of an app (especially because the compass on my phone keeps needing to be calibrated!).

Has anyone developed anything that would let me measure AltAz with a Propeller? I am sure I will need a compass and a gyro, but I am not all that great at electronics (why did you get into micro-controllers? you ask!), so if anyone has done a project similar to this that could help me save some time with the design of the layout and any programming, I would appreciate it.

I would like to hook this up to my laptop to give me a readout of the AltAz that I am pointing the telescope/camera.

Thanks in advance!

pbhuter

I have a Propeller Project Board USB, although I bought it several years ago, so it is not the same one shown on the website.

PaulRowntree

I am using the Adafruit BNO055 module, Tachyon Forth and a USB Project board. The output of the module is very easy to read (requires I2C clock stretching) and includes tilt-corrected compass headings as well as the tilt itself and the gravity vector. Much easier than coding up the tilt compensation yourself for a simpler IMU. If you are point straight up much you may want to use the quaternion outputs, which I hope I don't need on a sailboat The output readings are much more stable than what I was seeing with other boards.

Don't use an on-board VGA connector if the sensor is also on-board ... it disrupts the compass.

You might be able to get the Prop board to drive steppers too ...

pbhuter

Yes, I agree that working with an Euler vector (or even quaternions) would be easier - thank you.

I had planned to connect to my laptop through USB, not VGA.

I forgot that I had actually thought about motor control (just yesterday, actually), but I would like to have this be a module I can use when I have my camera on a ball-mount, which does not have a way to connect a motor. But I should probably look into the motor thing some more for situations where I am not using the ball-mount (like when I use a telescope)

Thank you!

PaulRowntree

BTW ... if you had a $10 GPS unit on board you could even program the World Magnetic Model so the compass declination could be adjusted automatically. Or type it in and store the information on SD or in EEPROM for the next run.