We started of this week’s session by looking at the recent Soyuz rocket launch which was to send two people to the ISS. During the launch one of the booster rockets failed and the launch had to be aborted. Both crew members, astronaut Nick Hague and cosmonaut Aleksey Ovchinin, escaped without injuries.
Official astronaut portrait of Tyler (Nick) Hague – Blue Flight Suit Picture. Photo Date: January 13, 2014. Location: Building 8, Room 183 – Photo Studio. Photographer: Robert Markowitz
We then continued to work on our pictures and messages for the Mission Zero Challenge. I made a video of some of the work we did, but it’s very hard to film LEDs so the quality is very poor.
If you want to find out more about the Soyuz incident and have another look at how to make pictures and messages with the Sense-hat LEDs my notes are here day 4.
Next Saturday we’ll start looking at Pygame Zero. See you all then.
Hello again everybody.
This week in the Bodgers group we started working on our code for the Mission Zero Challenge.
We began by writing a simple text message on the 8×8 full-colour LED display, then we changed the text and background colours. We then coded a picture by assigning a colour to each of the 64 LEDs on the display. We finished the session by taking a quick look at using the temperature sensor to read the temperature. Here are my slides from this week day 2.
Next week we will recap what we covered this week and we will start to personalise our code for the challenge.
In the meantime, here’s a couple of fun videos on how the Astro Pi computers got to the ISS.
Last Saturday we had a look at how we might figure out how far and how fast a bike is going using a Raspberry Pi. We used a very basic set up with just a micro-switch attached to a toy trike with a little nut taped to the front wheel, each time the wheel rotates the nut would “click” the micro-switch.
We would need to use a reed switch or a hall effect sensor and a magnet attached to the wheel if we were to use this on a real bike.
We started of our coding by looking at the time.time() function. This function returns the number of seconds, in decimal form, since 01 January 1970. If we want to time an event all we have to do is use time.time() to get the start time and use it again to get the end time and then subtract the the start time from the end time.
We used this to get the the amount time it takes to do one rotation. Now we want to find out how many rotations we have per minute or RPM (revolutions per minute). As our result is in seconds the easiest thing to do is calculate revs per second so we divide 1 by the time it takes to do 1 rotation and then multiply the answer by 60 to get RPM.
Now we wanted to get KPH(kilometres per hour) so first we measured the circumference of the wheel and found it was 50cm or 0.5 Metres. We then calculated metres per minute by multiplying our RPM by 0.5 and we then multiplied this by 1000 to get KPH.
Here’s a picture of what our results could look like when displayed using Pygame. We will look at Pygame later on as it’s an excellent way of displaying information.