Electronics Workshop Ideas

[Giorgos Karatziolas]

Hi all, 

I was hoping to ask a few questions and put forward a few ideas about the electronics workshop. 

First of all, what's the main goal? Should they leave the workshop having learnt some electronics theory which they can apply later to build things, or should they leave with some devices that they've created (eg sensors on perfboard). 

Either way, I think the eventual goal is that they'll have some sensors for their robots, either made by applying theory or following tutorials. At the last doing, the following sensors were suggested:

• Bump switches
• Ultrasonic rangefinders
• Variable resistors that react to various physical stimulus (eg being bent or pressed)
• Infrared tripwires

They should mostly be easy, my only concern would be the ultrasonic rangefinders. They tend to be complex circuits (too complex for them to solder together?) as well as that, interacting will them will probably require custom ruggeduino firmware. 

The rest sounds good though. Any further ideas are welcome, and as soon as I've got a confirmation of what the outcome of the workshop should be, I can start playing with ideas. 

Thanks, 

Giorgos

[Jon Bartlett]

Hi Giorgos,

>First of all, what's the main goal? Should they leave the workshop having learnt some electronics theory which they >can apply later to build things, or should they leave with some devices that they've created (eg sensors on >perfboard).

Based on the feedback from last year [1] (although I wasn't involved) it seems like students wanted more teaching than following docs, so probably a combination would be best.  Ideally they would learn how the thing works, why it would be useful to them in robot context, and then build and test devices.  How long is the workshop?

>Bump switches

>Ultrasonic rangefinders
>Variable resistors that react to various physical stimulus (eg being bent or pressed)
>Infrared tripwires

Seems like a decent range of bits - what about IR reflective collision sensing?

>They should mostly be easy, my only concern would be the ultrasonic rangefinders. They tend to be complex circuits >(too complex for them to solder together?) as well as that, interacting will them will probably require custom >ruggeduino firmware.

Depends on how long the workshop is I guess - I'd probably try to avoid the custom firmware bit as it seems (a) complicated and (b) only applicable to SR kit.  A simple ultrasonic sensor isn't too bad to make if there are a few people who do A level electronics though, I bashed one together several years ago using a PIC and a 555 that worked well over about 60cm-ish.  You could probably get something working fairly well with a couple of astables, simple amplifier, counter and DAC then read the output using the analogue pins on ruggeduino.  Might be a bit old fashioned (and big) though.

>The rest sounds good though. Any further ideas are welcome, and as soon as I've got a confirmation of what the >outcome of the workshop should be, I can start playing with ideas.

I imagine there will be a wide range of prior knowledge from the students attending, ranging from 'never used a soldering iron' to 'A grade at AS Electronics and does hobby stuff'.  It would probably be a good idea to have a series of increasing difficulty tasks and allow people to choose a starting point - maybe along the lines of dividing them into couple of smaller groups?  This would allow the weakest to start with 'basic circuit theory then make and test a bump sensor', middle group on an IR thing or variable resistor thing, through to the highest group starting with 'discuss a block diagram then build and test an ultrasonic ranger'.  This would depend on the length of the workshop and ability of the volunteers to support (and teach) the groups.

Jon
[1]https://www.studentrobotics.org/trac/wiki/2013/Smallpeice/Feedback

[Andy Busse]

On 28/06/2014 21:45, Giorgos Karatziolas wrote:

First of all, what's the main goal? Should they leave the workshop having learnt some electronics theory which they can apply later to build things, or should they leave with some devices that they've created (eg sensors on perfboard).

Main goal to have a "quick win" that provides students with some idea about what electronics means, preferably resulting in having something tangible which they may use on their robots.

Either way, I think the eventual goal is that they'll have some sensors for their robots, either made by applying theory or following tutorials. At the last doing, the following sensors were suggested:

• Bump switches
• Ultrasonic rangefinders
• Variable resistors that react to various physical stimulus (eg being bent or pressed)
• Infrared tripwires

They should mostly be easy, my only concern would be the ultrasonic rangefinders. They tend to be complex circuits (too complex for them to solder together?) as well as that, interacting will them will probably require custom ruggeduino firmware.

Depends. Ultrasonic was suggested as more of a "stretch goal" in case we get some slightly more experienced folks who find the simpler circuits a little too simple. If you have other ideas (perhaps weight, pressure, or something that gives an analog output)

Note that you can also get them as pre-assembled modules [0] (might be worth having a few of these around anyway, NB they also provide schematics for these), which are a little simpler to integrate. If we're ultra-budgeting, there are ebay special versions of these boards (might even order some tonight to see how good they are).

Thanks,
Andy

[0] http://www.technobotsonline.com/sensors/ultrasonic.html

[Harry Cutts]

Hi Giorgos,

On 1 July 2014 18:15, Jon Bartlett <twos...@gmail.com> wrote:

Seems like a decent range of bits - what about IR reflective collision sensing?

Reflective IR sensing (for collisions or for lines (less useful)) sounds like it would make a good little project; one could introduce op-amps through that.
 

I imagine there will be a wide range of prior knowledge from the students attending, ranging from 'never used a soldering iron' to 'A grade at AS Electronics and does hobby stuff'.  It would probably be a good idea to have a series of increasing difficulty tasks and allow people to choose a starting point - maybe along the lines of dividing them into couple of smaller groups?

There will certainly be quite a wide range of abilities. A series (or selection) of tasks of varying difficulty would be the ideal result, although also the hardest to pull off.

Harry Cutts

[Giorgos Karatziolas]

Hi all,

Here's a first draft of the basic level electronics tutorial, I've been putting it together during my lunch hours and a little after work.
I've also been working on some ideas for the more advanced labs.

I'm really just looking for plenty of criticism. If people like it, then it shouldn't take me long to get the other labs written.
If people don't like it please let me know why and I'll try and make it better!

Thanks, 

Giorgos

[Alistair Lynn]

Hi Giorgos-

A few minor spelling/grammar issues aside, looks good. It may be a little short - perhaps we could get some extension tasks?

There are a couple of fragments in there ('a relationship between voltage and current' and 'in circuits' as sentences on their own).

It may be worth giving the analogy between voltage and pressure if we're going for the hydraulic analogy.

Are there any microcontrollers which don't have a ground?

You've got V=IR repeated twice in quick succession, just in different forms.

Alistair

[Tom Leese]

Hi,

Generally, I think this is a good introduction into the key concepts of
electronics and I particularly like the water analogy since it's something
that's quite easy to visualise.

I noticed a few things which could be relevant, or perhaps the students own
knowledge may deem these unnecessary; see what you think.

Although you have described that "Voltage" is the "[...] difference in
potential energy [...]", It might be worth noting that the phrase "Potential
Difference" is the same as "Voltage" since the students might do some of their
own research online where only "Potential Difference" is mentioned (perhaps in
a glossary?).

The circuit is pretty self-explanatory in this, however it could be useful to
have a table of circuit diagram components and what they mean, especially the
more obscure ones. Perhaps this could be made available to the students as a
separate reference sheet?

Tom

[Giorgos Karatziolas]

Hi all,

Here's the second one. The updated first one and the third one will be following soon.

Once again, feel free to post any comments or ideas.

Thanks, 

Giorgos

[Jon Bartlett]

Hi,

> Once again, feel free to post any comments or ideas.

The big one for me is that there aren't any circuit diagrams for the circuits described, which would also help a lot with the explanations. For example, a circuit diagram with the current labelled for the phototransistor makes it easier to see what's happening. Just fyi, the most common issue when I teach ohm's law is understanding that v is the drop across the component.

Cheers,
Jon

[Giorgos Karatziolas]

Hi all, 

Here's number 3. Again, let me know what you think. My brain is a little fried, so they may be numerous spelling and grammatical mistakes (I'll sort those out tomorrow!)

Thank you all for the feedback on the other two, updated versions are coming tomorrow morning. 

There's still a lack of material for advanced students. I'll try to think of something for them to do tomorrow. 

Cheers, 

Giorgos

[Andy Busse]

Hi Giorgos,

Great work on these, thanks!

My comments would be to highlight where the actions are in each worksheet so that those with experience can skip ahead to the doing; I'd probably also add some questions at the end like you did for the first worksheet:
* Where would this sensor be attached to the SR elec kit?
* Think about how you'd mount this to your robot.

There were a couple of SPAG instances again but I suppose we can go through all of this tomorrow, when there'll be a few more sets of eyes.

Thanks,
Andy

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[Giorgos Karatziolas]

Hi all, 

Everyone here has helped me look over what I've put together. 
Here's the result. 

Let me know if there's any issues or features that you think should be changed. 

Thank you, 

Giorgos

[Jon Bartlett]

Hi Giorgos,

If you don't mind I'd like to have a go at simplifying these and adding more detailed guidance (maybe some photos or breadboard diagrams or something) to make SR sensor tutorials for the docs.  Obviously it's cool if you'd rather do that yourself.

Jon

--

[Giorgos Karatziolas]

Hi Jon,

Feel free to do whatever you please with the tutorials. There's a lot of room for improvement in them. As they are now, I think that they don't convey the theory very well.

I'm happy to contribute towards the changes, so let me know when you start.

Thanks,

Giorgos