Sydney PC User Group Newsletter 12 - 17 September 2016
Meetings for this week:
Programming: 6:00 - 8:00
The next meeting will be on Tuesday September 13 at 6pm. We'll see some new microprocessor applications and programming examples.
At the August meeting Andrew described using an 8 pin PIC to de-bounce a switch. His project had reed switches that can produce several rapid contact closures, rather than just the one they should. This is a common problem today when a microcontroller is used to count how many contact closures take place.
In his de-bounce program the first switch closure causes an interrupt event on a PIC12F629 input. The PIC wakes up and generates an output pulse, so masking any multiple switch bounce events, and then goes back to sleep. The width of the output pulse can be programmed to suit any type of switch. As the PIC is only running for a few milliseconds at a time the average power drain is very small. The current used by the PIC12 in the sleep condition is only about 50nA, so the design is useful for battery powered applications.
Steve gave a demonstration of controlling the Raspberry Pi and its interaction with peripherals, using the Python language. There are many good Python tutorials, for example: https://docs.python.org/3/tutorial/index.html.
Another way to learn it is through a series of YouTube videos by "ModMyPI" called "Raspberry Pi - GPIO & Python". There are 9 videos of about 10 minutes each. He said the videos get to the point quickly, and you can learn a lot in a short time.
Web Design: 2:00 - 4:30
Last month Steve issued a challenge to members to take a few photos and create a simple page. It will be interesting to see the results and we will discuss any issues people may have had building their pages. To help the design process the group will have a look at the idea of wire framing. This is where you create a mockup of the elements of a page using squares or rectangles to represent elements on the page. The best part is you don’t need a computer, just pen and paper. Wire framing also allows you to move elements around the page so you can see how each element would fit on a small screen and a desktop. Steve found a free tool which can give a wire-frame diagram of any site you like the look of. At the meeting we’ll try it and see how some of the more well-known sites have structured their layout.
Steve found a free responsive design course. The group will have a detailed look at it during the meeting.
Also can we send a message to everyone re the Vaya card offer. At the main meeting Vaya offered everyone a three month subscription for $1. To get the offer go to www.vaya.net.au and order a SIM card using the code PCUSER. A report will be on the site next week.
Next week's meetings:
- Tuesday Forum
- Family History
ASCCA Newsletters available for 2016 in PDF format:
Links from the Friday Comms SIG:
YouTube page for MIT App-writing Tutorials
Download Windows Installation program for Apps
Mozbackup (backup program for Firefox, Thunderbird etc.)