This Must Be A Record (For Me)

Let me see what happens when I paste from Google Docs...

	Part	Source	Quantity	Price	Total
ELF Tag	ATtiny85	Tayda	1	$1.15	$1.15
	DIP Socket	Tayda	1	$0.12	$0.12
	Zener Diode 3.6V	Tayda	2	$0.04	$0.08
	Resistor 68ohm	Tayda	2	$0.01	$0.02
	Resistor 1.5Kohm	Tayda	1	$0.01	$0.01
				TOTAL PER	$1.38

Well that looks ok in the editor.  It's obviously the parts cost list of the Lost and Found Fidget that I have just re-dubbed... the ELF Tag for "Electronic Lost & Found Tag".

Obviously these are not expensive in any sense except of course for the labor.

Sunday is Funday

Well I have started working on the PCBs for all of the Lost & Found Fidgets I am planning to make...

As such, I am getting good at making the boards.  These three are waiting for some components I should get later this week.  I have added everything that I do have, so that they will be quick to finish when the parts arrive.  The question is how many of these can I get made before then.  Here are the steps I have to perform for each one...

1. Cut out the front and back print outs (5 min)
2. Polish the blank PCB that has already been cut to size and clean (5 min)
3. Iron the front and back patterns to the PCB (15 min)
4. Soak in water, scrub to remove paper residue (15 min)
5. Etch (30 min)
6. Scrub excess toner away (5 min)
7. Drill, grind and smooth (20 min)
8. Solder components (20 min)
9. Clean and dry (5 min)

Total Time: 2 hours (per board)

For the next set of boards, I am going to try using the White Vinegar, Hydrogen Peroxide and Salt solution to etch the boards.  The bottle of Ferric Chloride I purchased from Radio Shack some time ago is about depleted.  It has taken on a nasty greenish tint, but actually still seems effective at etching.  I am just anticipating the move to a "cleaner" etchant because it is cheap and not as toxic.

The Trials of Toner Transfer

I decided to do a couple of boards this evening and had trouble with one of them (again) in the toner transfer step.  In both cases, the toner was not totally transferred and I had to start over. Very frustrating.

It seems I had not ironed the pattern well enough so next time I will have to make sure I do a more thorough job.  Perhaps I will go out tomorrow and get that laminater after all.

On the software side, I have been working on some sort of "light alarm" sketch.  I want to utilize the features of the Sound-Sensor board which means something that uses...

• 2 Buttons
• 1 Buzzer/Sounder
• 1 Light-Dependent Resistor
• 1 Thermistor

or at least a couple of the i/o.  

So far all I have is an alarm sketch that will trigger if the light changes from a specific setpoint.  To set the setpoint, just click the inner button.  This has the double action of clearing the alarm condition and silencing the buzzing.  It works pretty well, so I will probably keep this version.

What I will work on next is a "delayed" setpoint sketch that will wait... say ten seconds before taking the "sample" light level.  This way the device can be "armed", placed in a closed container and used as an entry alarm.  You could place it in a cabinet or a drawer and sound an alarm if it is opened.

I need to try and imagine some more sketches to use the board.  I should probably work on seeing if I can calculate the actual temperature from the thermistor.  That way I could build a "comfort" alarm that could use real values such as 72-76 degrees.

Ahh I should sleep soon.  Maybe I will dream of something!  

Weekend News

Here are some updates from this weekend so far...

I was able to figure out the problem with my Sensor Board and it was something really simple.  It seems the trimmed leads at the bottom of the sensor board were touching the tops of the pin selection headers of the Sound board.  Once I trimmed them a little more, the sensor board began reporting consistently.  Problem solved.

I finished the Lost & Found Fidget for Seth today.  I had run out of 3.6V Zener diodes, so I was waiting for my new order from Tayda to arrive.  But I found a pair that I had removed from an earlier board and they worked great.  So that leaves around 12 copies left to make for my co-workers.  I have most of the boards cut and the patterns printed, so I will begin transferring patterns en masse at some point.  I should do this so that I can etch multiple boards at a time.

One thought I had was to purchase a laminating machine for transferring the pattern to the copper-clad.  Right now I use a small iron and it does takes some time for each board.  Especially these double-sided boards.  I may look at a cheap one ($30) from an office supply outfit, to see if it is worth the purchase.

Cleaning Out The Closet

Well for a change, I am going to have a crack at this at a decent hour.  Maybe my thoughts will be more clear (ha ha).


Versions
Anyway, the first item I wanted to bring up is... what I am doing with all of these "iterations" I am going through of this thing I am calling a "fidget".  Well the best I can explain it I like the process of an "iteration".  It involves building the schematic and laying out the circuit in the CAD software.  Then I get to build the object I imagined.  I enjoy the steps I have to go through to make the device.  I prefer a more evolutionary style of gradually changing the form and function... and because I can leverage previous successes to increase the likelihood of the new device working.  

I guess I find it frustrating when electronics do not work the way you want them... it's sometimes hard to figure out why and that makes me feel a loss of control.  Something I am not comfortable with.  But when I build something, because is not much different than what I have built before, it usually works.

From another angle, I am also testing different configurations so that I can evaluate a device that I could build to give away as gifts to friends, co-workers, etc...  So there is some reason for all the different forms I have tried.

And it has all come down to this...

Original Fidget Device

• Set of 5 boards
• Base Board
• Comm Board
• POV Board
• RGB Button Board
• Sensor Sound Board
• 9v battery and connector
• DVD with software

I have given two set away so far... to James Rowe and Carlos Beltran... and I have a third set ready to go to James Sorensen out in Utah.  I am still not sure what to do with the fourth and last set.

Fidget Experimental Set

• Set of 8+ boards
• Three passthrough boards
• Four top boards

This is my personal experimental set.  I have an extra set that I could give to my father.  I don't think he would find the Original that compelling.

Fidget Lost & Found Fob

This is the last revision that has removed ALL extra features.

• Minimal components
• Built-In USB Male connector
• One essential function

This is the final version that I have come up with in the last few days.  It is essentially an electronic lost and found tag.  You plug it into a computer and it starts up notepad and begins typing out a pre-defined message.  I think it will be my best choice for the rest of my co-workers that did not already get something. Maybe.

Sensor Board Troubles

As I have been experimenting with the thermistor and LDR I have noticed some anomalies with the values that I am reading.  What seems to be happening is that using the two analog inputs A0 and A1 does not give accurate values for either when both are read.  If only one is read then the values come out as expected.  Why is this?

I have tested this on my ATmega328 (Arduino) and it works as expected.  So I do not know what is going on.  There are some hints on the interwebs but nothing that has solved my problem.

The next step will be to test the two other analog inputs... with the only problem being...I cannot get the analog values anymore via the DigiUSB library... because they need those pins.  So I will have to devise some sketches that can indicate the values some other way.  One possibility is with LED lights... such as the Charlieplex shield that I have.

Probably the most fun solution will be via serial communications to an LCD screen.

Anyway, until I can figure some things out, the sensor will have very little to show in the way of sketches.  But I will work on getting some ideas up and running...

• Drawer/Cabinet Alarm
• Temperature Alert
• Light Organ

Chalieplexing Success

On a final note, I was able to decipher the charlieplexing sequence and reliably control six LEDs from three data lines.  I was able to make this neat little die roller, using the button board.  I used the library found here.

The Daily Report

Only a few more minutes to get this report in...  :-)

Well I finished the fidget for Lisa and here it is...

I am pretty sure this would be the way I would go for the rest of the crew.  The only thing that bothers me is the USB connector.  While on one hand, it is very convenient, on the other it is rather "unprofessional".  I have seen through-hole, right angle USB A male connectors available on Aliexpress, but the do not seem common.  Although if the intent is occasional use then the connector is quite appropriate.

Weekend Update

I was able to get a lot done this weekend... and probably did not sleep enough.

I burned four small DVDs with the Fidget software.  That should be enough copies for the sets I am giving away.  The question is... how many sets and I going to make and give away?  As I consider my friends and co-workers that I believe would enjoy such a gift, one name comes to mind.  Matt maybe... he seems to have wide interests.

I was also able to complete all the boards I had etched earlier.  That gives me two complete OSI sets, a complete Fidget set and some extra boards.  I should focus now on developing apps for the boards.

Finally, I constructed the key chain version of the clone.  I guess it is no longer a clone of anything anymore.  Here it is...

 It is a small board and has very little in the way of components... but is very versatile.  This first one I made for a co-worker and I think it turned out well.  I had to use double-sided copper-clad to get the traces for the USB connector.  Otherwise, the components would have to face down.  I was originally worried about alignment of the wire vias between the front USB pads and the back side copper.  Fortunately, this worked out pretty well by pre-cutting the PCB and using the edge lines as cutting guides.

The only problem I have is that of labor.  It took a good chunk of the day for the build and that is too long for some 17 odd copies that I need.