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by Davespice
Fri May 20, 2016 10:35 am
Forum: Astro Pi
Topic: Sense Hat temperature reading -200 degrees?
Replies: 76
Views: 26294

Re: Sense Hat temperature reading -200 degrees?

Hmm, I think we need to investigate this. Would anyone volunteer to send us one of their Sense HATs for analysis?
by Davespice
Fri May 20, 2016 10:33 am
Forum: Astro Pi
Topic: Set_rotation messing up accelerometer values?
Replies: 4
Views: 1658

Re: Set_rotation messing up accelerometer values?

I think it's because you're using .values() this returns the values unsorted. So it will look like the axes are changing all the time.
Try this instead;

Code: Select all

accel = sense.get_accelerometer_raw()

x = accel["x"]
y = accel["y"]
z = accel["z"]
by Davespice
Sat Feb 27, 2016 7:57 pm
Forum: Astro Pi
Topic: Do not wait for show message to finish
Replies: 1
Views: 1196

Re: Do not wait for show message to finish

Hi there, I remember you from last time! You want to look into the Python threading module. This allows you to kick off a function and return immediately to go onto the next line of code leaving the function to run in the background. Example: import time import threading as th from sense_hat import ...
by Davespice
Tue Feb 23, 2016 5:12 pm
Forum: Astro Pi
Topic: Sense Hat Issue
Replies: 11
Views: 2713

Re: Sense Hat Issue

It's just used to suppress or filter the amount of high frequency electromagnetic interference (EMI) coming from the 5 volt power supply you're using.
by Davespice
Tue Feb 23, 2016 5:10 pm
Forum: Astro Pi
Topic: Do I have a 'faulty' Sense Hat?
Replies: 5
Views: 2756

Re: Do I have a 'faulty' Sense Hat?

Hi there, if you're using the get_orientation or compass functions then something called a Kalman filter is being employed by the underlying Python code. This keeps three Euler angles (pitch, roll and yaw) and uses input data from the Gyro, Accelerometer and Mag to continually update them. If your M...
by Davespice
Tue Feb 23, 2016 5:00 pm
Forum: Astro Pi
Topic: reboost to new orbit detected by 'Ed'
Replies: 1
Views: 1100

Re: reboost to new orbit detected by 'Ed'

That's right. So Ed has finishing running two student experiments ( Crew Detector and SpaceCRAFT ) and is now running a data logging program which is gathering sensor measurements into a database for this educational resource . You'll be able to download the CSV file and look for the reboost in the ...
by Davespice
Fri Feb 19, 2016 12:24 pm
Forum: Astro Pi
Topic: Sense Hat Issue
Replies: 11
Views: 2713

Re: Sense Hat Issue

Ah if it's FB1 in the top left corner, this is a ferrite bead that connects 5 volts to the board. You can replace this with a wire bridge.

Image
by Davespice
Fri Feb 19, 2016 12:00 pm
Forum: Astro Pi
Topic: Astro Pi Temperature Sensor Reading
Replies: 63
Views: 42315

Re: Astro Pi Temperature Sensor Reading

That may be due to the properties and accuracy of the sensors, I know the pressure sensor's temp reading is much less accurate.
I'll link the data sheets and you can take a look;

Pressure ST LPS25H
Humidity ST HTS221
by Davespice
Fri Feb 19, 2016 11:55 am
Forum: Astro Pi
Topic: Sense Hat Issue
Replies: 11
Views: 2713

Re: Sense Hat Issue

Can you post a picture with a circle drawn around the area of the mission component?
Try and make sure it's in focus, blurry pictures won't help. Then I should be able to tell.
by Davespice
Thu Feb 18, 2016 8:11 pm
Forum: Astro Pi
Topic: Astro Pi Temperature Sensor Reading
Replies: 63
Views: 42315

Re: Astro Pi Temperature Sensor Reading

Hi folks Just wanted to chime in here. This is a known issue with the Sense HAT, there is thermal conduction from the Pi 2 CPU through the PCB top and bottom fill to the humidity and pressure sensors (which also give you temp). We should have pulled back the fill around these sensors to avoid this b...
by Davespice
Thu Feb 18, 2016 7:56 pm
Forum: Astro Pi
Topic: Sense Hat Issue
Replies: 11
Views: 2713

Re: Sense Hat Issue

from sense_hat import SenseHat sense=SenseHat() sense.set_pixel(1,1,255,,0) then do a sense.get_pixel(1,1) the return value is (248,0,0) Hi there! This is an expected behavior due to how the numbers are bit shifted to fit into the Linux frame buffer memory. It's explained in the API documentation h...
by Davespice
Tue Dec 01, 2015 4:49 pm
Forum: Astro Pi
Topic: Sense HAT on Pi Zero interim fix
Replies: 13
Views: 5536

Sense HAT on Pi Zero interim fix

Hi folks;
There is a known issue with using the Sense HAT on Pi Zero. To fix it you'll need to do two things:

Code: Select all

sudo rpi-update
and then add the following line to the end of /boot/config.txt

Code: Select all

core_freq=250
This will be resolved by a future update.
by Davespice
Mon Jul 20, 2015 3:01 pm
Forum: Astro Pi
Topic: Astro Pi HAT Weight?
Replies: 2
Views: 1087

Re: Astro Pi HAT Weight?

Excluding the header, screws and stand-offs the sense HAT weighs 17g.
by Davespice
Fri Jul 17, 2015 10:39 am
Forum: User groups and events
Topic: Open invitation: Participate in Outernet's first edit-a-thon
Replies: 0
Views: 761

Open invitation: Participate in Outernet's first edit-a-thon

Hi all, a few weeks ago we posted on our blog about Outernet . THIS WEEKEND they are holding an open event (along with Creative Commons) where you can participate in the process of converting web content into a form that can be broadcast through their satellite service globally. Consider this questi...
by Davespice
Wed Jul 15, 2015 1:04 pm
Forum: Astro Pi
Topic: So we were nominated for an Arthur award!
Replies: 3
Views: 1031

So we were nominated for an Arthur award!

Hi folks, I just thought you might like to know that Astro Pi was nominated for a Sir Arthur Clarke award (we found out last Friday). These recognise individuals and teams that have made notable or outstanding achievements in, or contributions to, any kind of space activity. Also known as ‘The Arthu...
by Davespice
Mon Jul 06, 2015 9:50 am
Forum: Astro Pi
Topic: What are the values returned by get_compass_raw measured in?
Replies: 4
Views: 1071

Re: What are the values returned by get_compass_raw measured

We've just checked this out and the unit is indeed microteslas. Thanks for pointing this out.
P.S. The LSM9DS1 datasheet says gauss but this is converted by RTIMULib into microteslas before it's passed up to the Astro Pi library.
by Davespice
Mon Jul 06, 2015 9:48 am
Forum: Astro Pi
Topic: Did everyone make the deadline?
Replies: 2
Views: 799

Did everyone make the deadline?

So it's closed now, we're doing the judging tomorrow here at Pi Towers. I hope you all got your code in on time!
Thanks again for your participation and support.

Dave :D
by Davespice
Sun Jul 05, 2015 7:53 pm
Forum: Astro Pi
Topic: The python source code and an executable file??
Replies: 7
Views: 1272

Re: URGENT HELP

However this is all guess work as no one involved with the project has commented. ShiftPlusOne did reply with: The .py file is what they mean. Which is correct, you just need the .py file if you're submitting Python code. That comment about executable files is only on the website for people who mig...
by Davespice
Fri Jul 03, 2015 3:27 pm
Forum: Astro Pi
Topic: LED Board stuck
Replies: 2
Views: 1044

Re: LED Board stuck

Please have a read of this post, particularly under where it says WARNING in capital letters :)
by Davespice
Thu Jul 02, 2015 4:58 pm
Forum: Astro Pi
Topic: Simultaneously use both push buttons and joystick
Replies: 1
Views: 1737

Simultaneously use both push buttons and joystick

Hi folks Okay so I just wanted to post some example code here to help those of you who are writing games for Tim Peake to play. Perhaps you want to use the joystick to move and the GPIO push buttons to fire ? Information on using the joystick can be found here and on the push buttons here (you'll ne...
by Davespice
Thu Jul 02, 2015 10:34 am
Forum: Astro Pi
Topic: how to analyse images from results of pi camera?
Replies: 2
Views: 843

Re: how to analyse images from results of pi camera?

Yeah YUV is a good one to use. More info on how to do that through the picamera library here . The other issue you may have is that the camera can perceive visible light as well as IR light, so if you only want to look at IR light you might need a visible light excluding filter in front of the camera.
by Davespice
Thu Jul 02, 2015 10:29 am
Forum: Astro Pi
Topic: What are the values returned by get_compass_raw measured in?
Replies: 4
Views: 1071

Re: What are the values returned by get_compass_raw measured

I'll double check this.
You may find that the mag doesn't behave correctly until you've calibrated it. Make sure you note this post at the bottom.
by Davespice
Wed Jul 01, 2015 5:54 pm
Forum: Astro Pi
Topic: Joystick and Push Buttons
Replies: 15
Views: 2561

Re: Joystick and Push Buttons

Every line of code and every binary file will be checked for every winner. There is no way anyone will get anything past us.
Don't underestimate the resources at the disposal of ESA and NASA :D
by Davespice
Wed Jul 01, 2015 4:41 pm
Forum: Astro Pi
Topic: Joystick and Push Buttons
Replies: 15
Views: 2561

Re: Joystick and Push Buttons

* Writes program which buffer-overflows, overwrites the kernel in memory, installs custom hobby OS in the place of Raspian, reboots into said OS, ignores warning... * Just remember we are going to triage all the code that is going on the flight SD cards and something like that is never going to sli...
by Davespice
Wed Jul 01, 2015 3:56 pm
Forum: Astro Pi
Topic: Joystick and Push Buttons
Replies: 15
Views: 2561

Re: Joystick and Push Buttons

I've attached a picture of the flight unit for clarity, the little red track-point cap is the joystick. The user will probably use their left thumb to move it. You won't be able to override the reboot/shutdown functionality from your code, that is being controlled at Kernel level. But if you wanted ...

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