programmable logic gate 1.0

programmable logic gate

programmable logic gate

This is it: the first version of the logic gate. The built-in Arduino can be programmed, for example, with S4A (Scratch), but there is also a built-in AtTiny24a as an alternative LED control. I forgot to add the pull-down resistor for one switch (the one for selecting AtTiny24 or Arduino) in my fritzing circuitboard design, but once this has been updated, I might publish it on their page as part of the documentation. Most of the documentation is in a oneNote file at the moment, and now I am thinking about where and how to document it on the web.
I’m also planning to make worksheets and prepare scratch files for use in labs or lectures. First of all, however, it’s now time to clean up my personal “hackerspace”. 😦

PS: Thanks to John for proofreading this text.

freely programmable logic gate

thats what I am working on at the moment. It is programmable using scratch and s4a but still needs some improvement on the appereance.

Scratch

Back

Front

circuit diagram

 

 

 

 

 

 

 

Next steps will be:

• Label the front
• Build a case, maybe attach the arduino somehow
• “Programm” the full example code in scratch
• Test the  response of students (and friends)

Possible further steps:

• Rebuild it with improved material (a “real” circuit board, a better case, a dedicated arduino)
• Connect it to the piface

Update:

Labeling

Kept on thinking…

…looks like development is always about compromising.

S4A is really nice but using it means abstaining from a lot of input/output-Pins, left alone the shields. But on the other side using Scratch is very inviting… so I now came up with the idea of combining it.

I’m happy with a slim version using S4A  for the very first impression. Being able to switch to a complex version using as many of the capabilities the arduino offers as possible would be great.

Anyway, I’ll keep on thinking 😉

Getting the PiFace connected

One of the reasons to buy the Pi was the PiFace. My job at the uni gives me the possibility to help out if a lecture is cancelled or if a group of possible future students is around.

What I would like to have for these occassions is a prepared lecture (or lab) showing the appliance of programming. The age and experience of these groups is assorted and unknown until the start. Looks like I need a lesson that I can adapt on the fly.

This week we had our “Study on Trial”-Week where I did a Scratch-Lab for 6 people. The day before I found a way to connect my Arduino to Scratch (S4A) and thought that this could be a way to get people involved.

As extension to Laptop+Arduino my idea is now to combine Pi with PiFace.

I’m using this Blogpost as source.

Activating the SPI Driver by editing the file /etc/modprobe.d/raspi-blacklist.conf:

sudo nano /etc/modprobe.d/raspi-blacklist.conf

Insert #:

#blacklist spi-bcm2708

(good to know that i2c can be enabled in this file aswell)

Now there is a German saying: Reboot tut gut (reboot, thats good).

Installing PiFace digital libraries (according to this post):

sudo apt-get update

wget http://pi.cs.man.ac.uk/download/install.txt

bash install.txt
And again reboot.

Scratch
Thats were I am struggling a bit at the moment.
This post seems to be helpful. But before beeing able to do the “shift-click” thing its necessary to enable “Mesh” as described on this Page. Scratch crashes when I’m trying to save the image.

Thats enough messing around for today 😉

 

Update: After starting scratch from LXTerminal using “sudo scratch” changing the image worked. I think I’m going to to a proper post about connecting scratch later.