Saturday, October 10, 2015

Kids Robot

I recently promised my daughter we would make a robot together, one that could make drawings.

After searching for some inspiration, I found a really simple one, here, that could be easily built and that she could understand.

So here are my plans, most steps, if not all, can be make by the children with some assistance:

Materials: a battery holder, motor, switch, tie wraps, and a piece of wood; some basic tools are also needed. I have pre-drilled the wood with 6 small holes for the feet, and 4 larger holes for the motor mount, and pre-soldered long wires to all electric components, so that the child can connect them.

Kids: Cut 3 lengths of solid core wire, strip it, and bend it to fit the holes, see next picture:

Kids: Mount like this!

Kids: Mount the motor with the tie wraps. Mount a thin flexible tube on the motor. Here I used a bit of thermo retractable sleeve. On the tip of that you mount a tip of a pencil.

Kids: Also the battery holder.

Connect it all via the switch. I used a push button, but a regular ON-OFF is also fine! even better maybe would be a ON-OFF-ON to reverse the direction!

Here it is a better view!

It then got decorated with antennae and mouth :) The kids really enjoyed it!!!

The idea is that the vibration both draws and makes the robot move. Mine was a bit too heavy to move, but I'll work on that!

I'm already thinking of the next ones! slightly more complex!

Sunday, September 27, 2015

GoPro waterproof case power supply

Back quickly, and back to electronics! Or in this case, electrics!

The problem is well known: You have a GoPro camera and would like to power it beyond the battery life for e.g. some outdoor long time-lapse movie.

There are some external batteries available, and some projects that connect a USB cable through the case, but they either require a hole in the case to pass the cable, or involve some very thin conductors, which, do not damage the case, but do potentially compromise the water proofness of the case.

So here's what I've done:

Got a USB cable and stripped it to the connector, and trimmed the connector as to be able to put the camera with the cable back in the case:

Connected the 2 power wires to two of the buttons on the case, from the inside.

Since the buttons are metallic, all that is left is to connect the other end of the USB cable to the buttons on the outside! Lo and behold, you have power to the camera via the buttons, with no damage to either camera or case, and all it costs is the price of the USB cable, which you probably have lying around anyway!

Next step is to make a nice connector to put on the outside over the buttons, with all the wiring!

Friday, September 25, 2015

I'm back! and this time with a completely different project!

I've been away from posting here, as I did not have much available time to report.

I did some things, which I still intend to report, but this time, I am redoing the upholstery on some old chairs!
These are some pretty old chairs, that belonged to my grand-mother, so they are at least 40 years old, I guess more than that.

About 15 years ago I replaced the internal foam and elastic bands on the sitting area, but left the top intact. Now, after an unfortunate incident, the cloth got destroyed, so I had to fix it!

Started by removing the bottom from the chair, and the artificial leather cover.

You can appreciate the work that went into the cutting and placing of the cover!

The round headed nails were placed by me during the foam replacement. The original nails are the flat headed, and they are very short and tapered, very interesting nails! Possibly special upholstery nails...don't know...

I then cut a piece of new material and stapled it all around. It is not as stretched as I would like to, but it was the first time...I'll try to do better for the second chair!

I also inserted some screw studs (sorry don't know the correct name) to be able to use metal screws instead of wood screws.

Overall the result is pretty neat! but I'm not gonna do the back, as that is something for a professional.
The photos aren't great, but the phone was all I had around.

I'll try to make a time-lapse movie of the repair of the second chair! stay tuned!

Saturday, January 18, 2014

Digital Photography

This will be a short post (good news!)

Just was busy doing my photo backups, and decided to make a graphic to see the evolution of storage needed.

I have had a digital photo camera for 10 years now. Started with a very very nice Minolta Xt, which I still think was the best compact I ever had (only had another one after that :), and eventually moved to a digital SLR, and now a SLT.

So here it is, the number of photos taken, and the associated storage. I think one can deduce the year I bought the first SLR and the year I upgraded it to a model with so much more pixels!

Note: I bought the first camera in Christmas 2003, so the bars don't make it to the visible area :)

Thursday, November 28, 2013

Fan Controller reloaded II

So here is the continuation of the previous chapter, the saga for a nice product.

Final version:

The eagle eyed among you might notice some small changes. Nothing major.
The ones really paying attention might notice the mistakes: DS18B20 is one wire, not I2C, as is indicated (cosmetics), and the silkscreen for the 12V and the 5V regulators is inverted (cosmetics with high potential for disaster). The soldering holes for the screw connectors could also be a tiny bit bigger, but that depends on the connectors used (could be problematic, as I used some big ones).

I only noticed these mistakes after the boards arrived, luckily before soldering the regulators, so no harm done!

but, following the intense design sessions, I sent it out to be manufactured by Fritzing, and the boards arrived, a bit more than a week later! Great service is all I can say. Here they are in all their glory:

 I really think they came out amazing!

And here in the box, with some components located, not soldered yet:

And finally, in the box, with the components (attiny is missing):

In the third chapter, the completed thing, with screws, micro, lid, everything! and some considerations for improvements.

Wednesday, November 27, 2013

Fan Controller reloaded

I've been busy redoing my fan controller, and now, that I'm about to post about it, I just realize that I never presented the previous work finished, so here's a picture of the prototype:

So there it is. I especially bought those little orange and gray connectors to try out for this project.

It had been working fine for one year, but the power supply that comes with the radiator is in a DIN rail format, so I have been wanting to find a DIN rail enclosure, and make a PCB to put inside it.

I found a nice box in Conrad, and proceeded to make a shield for a JeeNode, that would fit the box. I decided to use Fritzing, to try out the manufacturing service.

1st attempt:

Great! only to realise, that the JeeNode on top of this would cover the access to the screws of the connectors. Not to mention, that the box had some mechanical constraints.

2nd attempt:

Notice that I have completely replaced the JeeNode by a Attiny of 8 pins. I decided I do not need statistics on this. So it is now a fully standalone micro-controlled controller.
notice also the mounting holes in the middle, and a big hole for a big plastic column in the box (pictures will follow). Time to print the thing and check that it fits.

3rd attempt:
Of course things didn't really fit, so I had to shift a few things around. I also decided to add some connectors to make the whole thing tidier. This is almost it! 

In the next post I'll put some pictures of the final product: beautiful boards, made in Berlin! and the assembled thing.

Wednesday, October 9, 2013

CF to SATA adapter fix

Some time ago, I bought a motherboard (ASUS AT3IONT-i) and a large disk for a project I had in mind. It was the first SATA disk I ever bought, so I was curious as to how that worked.

Plugged it all, and the disk did not work...never got recognised. Strange.

After a lot of investigation, and blaming it on the disk, I remembered I had a CF to SATA adapter lying around bought in a trip to Taipei's electronics area, so decided to give that a try, to rule out the disk.

As I plugged it in, smoke! from one of the regulators. Very strange. Upon some quick investigation, I found out that the 5V and the 12V lines on the power cable were switched, the one that came with the Motherboard. I was upset and thinking of how would they look at me in the shop if I show up with such an argument, that the lines in the cable are switched.

But it was late at night, and I wanted to get it done, so I just disassembled the cable and reassembled it properly. Unfortunately, no pictures of that. All was well afterwards! Except for the adapter that was burned.

So last time I ordered something from Conrad, I remembered that, and ordered some regulators of the same kind. Tonight I did the switch! exciting, as they are SMD components, but it went much easier than expected! Here are some photos:

Burned regulator, AMS1117-3.3

 Regulator removed

New regulator in place!

Now the adapter will go into the black hole of computer components, never to be used again! but at least it is fixed!