Arduino Workshop

Yesterday the Arduino Workshop that Lennart and I organized, took place in Velsen. Quite a day it was… Leaving home @ 06:45, picking up 2 hitchhikers and arriving at 09:40.

Arduino on a breadboardThe workshop started with a presentation by Lennart, followed by handing over the kits and handouts to the participants. And then it didn’t take long before the tables were crowded with soldering irons, laptops, breadboards, ATMega’s, jumper wires and so on. For some this was the first time they ever had a soldering iron in their hands, others brought their own soldering iron with them; the level of experience was very broad. But, by helping each other, most people managed to create a breadboard Arduino with a blinking LED, and went home with a soldered Bridge Board, Room Board and JeeNode 🙂

During the day Jean Claude Wippler also demonstrated his reflow setup and I wanted to demonstrate the HomeSeer Integration of the JeeNodes. However, at the moment suprème, something went terribly wrong: my JeeNode, which had worked flawlessly the whole day and made Homeseer speaking “Motion” all the time, suddenly refused to work.. What a bummer! And nothing helped; rebooting the laptop, changing COM ports, nothing! Aargghh!!

Arduino Workshop

It was 20:30 when I came back home. Enough for today… well, that’s what I thought during the 1st hour… but I just couldn’t cope with the fact that my demonstration didn’t go as planned. I just had to see it working again! So I took the JeeLink and JeeNode with me to my hobby room, booted my PC, hooked them up and started HomeSeer. Guess what… it worked, as if it had never stopped! I don’t recall inviting Mr. Murphy to our workshop, but apparently he did pay us a visit in the afternoon…

The description of how to get the HomeSeer integration working is all in the handout, so I’m sure all the participants that want to get this working will have no problem doing that at home.

Despite the fact that I was not able to demonstrate the Homeseer part, I’m looking back on a successful day on which I hope the participants have learned a lot – enough to catch the Arduino fever! 🙂

Surfacing the spoil board

Yesterday I had a few hours to devote to my Mantis. The power supply, Ultimaker board with Arduino MEGA had to be attached to the back of the Mantis, the wire  mess needed to be taken care of and some other things needed to be dealt with before I got to the point where I could let my Mantis do some first serious milling. The closer I got to that point, the more I sensed some nervousness; after working on this machine for 5 evenings and an afternoon, would it really work???

The last issue I took care of was the spoil board. The one that was supplied wasn’t thick enough (caused by a design hickup), so the cutter couldn’t even reach the original spoil board at it’s lowest Z position. So I took a piece of 18 mm MDF plate and made my own. With the additional 6 mm in thickness, the cutter could now cut into the spoil board deep enough to perform the initial surfacing.

Now it was time to really start doing serious stuff instead of clicking the X, Y and Z buttons… so I mounted the spoil board, hooked up the Mantis to my laptop, started ReplicatorG, opened a G-Code file to surface the spoil board and clicked the build button.

YES, it works! OMG, this is beautiful! 🙂 Some issues though…

The cutter moved too fast. I could hear that the rotary tool didn’t like the speed with which it had to cut. I modified the G-Code and adjusted the feed rate (the F variable) to slow down the movement of the cutter, but that didn’t help; so after that I created my own G-Code with help of a facing tool and decreased the stepover percentage to 10%. That did the job; now the rotary tool no longer ‘complained’ and in 20-30 minutes the spoil board was done.

Another issue is the dust. Maybe the amount of dust that was produced is caused by the use of MDF as spoil board, but doing this in a room of 4 m x 6 m x 2.10 m with 4 PC’s nearby is not a wise thing to do I guess; when the slots for the floor heating were cut into our concrete floor earlier this year, 2 DVD players stopped working afterwards; I hope this won’t happen again!

Also, the connection between ReplicatorG and the Mantis isn’t 100% yet; whenever I use the Control Panel to manually control the Mantis and try to do a build after that, the Mantis doesn’t respond; only after disconnecting the USB connection and restarting ReplicatorG, a build will succeed.

Despite these issues I’m pleased with the results so far. I uploaded some images and below you can watch some video’s of the surfacing process.

Better than the real thing

This time I won’t post about my own Domotica adventures, but someone else’s: Menno van Gennip.  A few days ago Menno posted on the Domoticaforum about his self-made Remeha Calenta interface. For several reasons, his work just needed to be mentioned here.

First of all, the way Menno improved on the TTL-RS232 converter is beyond my knowledge and absolutely a great improvement. Menno added galvanic isolation to protect the Remeha. Second, he added an Ethernet interface based on a Ethernet-serial Wiznet module:

Galvanic isolation

Third, Menno put all the electronics in a nice enclosure including status LEDs:

Inside the enclosure Interface enclosure

Fourth, Menno created 2 Homeseer scripts that makes the whole thing ‘Homeseer-ready’, including CRC checks and all:


The screendump below shows the Homeseer status screen with all the information from the Remeha Calenta (click it for a larger view):

And last but not least, the reason why I like Menno’s effort so much is that this is a very good example of what can be accomplished by sharing knowledge; Menno’s knowledge about electronics combined with my earlier findings about the Remeha Recom protocol resulted in a interface that’s even better than the “real thing”, being the Remeha Recom and the Remeha Interface cable ! (for us Domotica enthusiasts, I mean).

Chapeau, Menno!

Reviving old stuff

This is something I really like about the world getting smaller and smaller all the time: finding spare parts is a lot easier than before. Whenever a device stops working, whether it’s a PC or anything else with a power cord, it eventually ends up on my desk with the question “can you fix it?”. Since opening things is one of the favorite things to do, I never let a chance go by to do just that, as with this old 8mm film projector. There seemed to be something wrong with the film transport inside; well, that’s quite an understatement as you can see:

8 mm film projector Vulcanized belt

The belt was completely vulcanized and came out in pieces, all dirty and sticky and needed to be replaced.

Now where do I find a replacement? I measured the diameter for this belt, but could not find a suitable one.

OK, this won’t lead to anything good; let’s search on the brand and model of this film projector. Bingo, first hit! There seems to be a Dutch company specialized in digitizing old 8mm films and they also have spare parts for numerous old film projectors. And they even have a web shop … A few clicks later, the right belt was ordered. Now this film projector will be revived in a couple of days, so our children can see what their mummy looked like when she was their age 🙂

I wonder if I would have gone through all the hassle to find a suitable belt in the pre-Internet ages: finding a shop in town that will help me find the replacement, ordering it, going back to the shop once more to get it, etc. etc… Yuck!

Maybe it’s a good idea to digitize these 8mm films before another part of the projector breaks down…

Different breadboards

As part of preparation for the Arduino Workshop, I was soldering a new Bridge Board a few days ago. The Bridge Board is, just like the AA Power Board, a very handy tool that helps you  keep all those experiments you do on a breadboard clear, simple and easy to build.

After soldering the row of pins that will be pushed into the breadboard, I wanted to see what it was going to look like. I took a random breadboard and immediately saw something was wrong here.. I’ll never be able to connect the JeeNode to the Bridge Board ?! This is strange; this being a design flaw was out of the question of course, so I took another random breadboard. Now the Bridge Board (better: the breadboard :-)) dimensions are correct! Just look at the horizontal white line across the Bridge Board; this should be in line with the outside of the breadboard:


The cause is quite obvious: not all breadboards are equal in size (click the images for more detail). The left breadboard that fits perfectly has a width of 54.2 mm while the breadboard on the right, which is unusable in combination with the Bridge Board, measures 64.5 mm. Well, this is something I never realized before: even breadboards with the same amount of tie points can have different dimensions. So much for standardization…

So if you’re a potential Bridge Board user, watch out what breadboards you buy.

The Mantis



Yep, time for something completely different! Is it? Not for me, although the relation with Domotica might be less obvious. Last Tuesday I attended the 2nd evening of the Mantis workshop which is held at ProtoSpace.

Protospace Protospace is not just a standard laboratory; it is based on the FabLab concept of MIT professor Neil Gershenfeld. It’s a typical place where designers, inventors, artists, students and educational institutions can meet and bring their ideas to life.

What we are building is a modified version of the Mantis-9 CNC Mill, which is described in detail here. The workshop consists of a total of 4 evenings, so half of the workshop is already over. Time really flies! The construction still needs quite an amount of work, so that’s why we were given some ‘homework’ in the form of soldering the PCB that will be used to control the Mantis. This leaves more time to spend on the construction during workshop hours. The PCB that will be used to control the Mantis CNC Mill is the Ultimaker Board, which is also used in the Ultimaker project. The PCB and a bag full of loose components should result in the following:
This PCB is in fact a large Arduino MEGA shield, cause that’s what is also needed to control the Mantis – the Arduino MEGA will act as the ‘link’ between the PC and the Mantis.

What do I need this Mantis CNC Mill for?
Nothing in particular, but a lot of things! And I’m sure the rest of the family will come up with enough ideas too, when they get a notion of what you can do with the Mantis. The first thing I want to accomplish is PCB milling. I hate experimental PCB’s and volumes are too low to have PCBs made at an affordable price (tooling costs…). The Mantis looks like a great way to get around this ‘problem’. From there we’ll see what the next focus will be. And the main reason of course why I enlisted for this workshop: it’s lots of fun to build it!

All those adapters

It’s time to follow up on some energy saving tricks I know about for quite some time, but which I didn’t implement yet.

A couple of places in my house are crowded with power adapters. One of them is the meter cabinet. Over the last 5 years, the number of devices just kept on growing, and of course they all came with their own power adapter. And when you touch those adapters, you can feel they all produce heat. Some are really warm actually, and look quite old. And heat means inefficiency; so it was time to make a list and see if I can reduce the amount of power supplies. It looks better, and from what I’ve heard from others, this exercise can  result in a relatively substantial yet ‘easy’ way of saving energy. So let’s do it!

So what do we have in the meter cabinet:

  • an old POTS PBX;
  • Visonic Alarm system;
  • Siemens M20T GSM modem;
  • Synology NAS;
  • PLCBUS PLC1141 Interface;
  • ACT TI-213 X10/A10 Interface;
  • RFXCOM RFXMeter;
  • Sollae EZL-400;
  • D-Link 8-port 1Gbps switch;
  • Alphatronics Visonic receiver;
  • Fritz!Box WLAN 7170.

7 of these all have their own power adapter. But looking at the output voltages of these adapters, it comes down to 9V AC, 5V DC and 12V DC. So why not combine those 7 devices to 3 adapters? So I ordered 3 new adapters with a higher wattage that should be able to power those 7 devices.

Power Monitor

Power Monitor

Do I have any idea what I will gain in energy saving by doing this? No, not yet; but I’m going to use my good old Power Monitor PRO for that; I bought that thing at least 10 years ago I guess; I think you can remember those days, when energy saving was considered silly, a waste of time; who cares?? Well, I did 🙂 A lot has changed since then.