Category: Blog

Solar logging update

I was not really happy with the logging of the SMA solar inverter. The site was always a few hours behind and the graphs are averages, so I do not realty trust the data. I searched a bit on the internet and found SBFspot. This program runs on a raspberry pi and reads out the inverter and sends the data to PVoutput.

I had an old V1 raspberry pi 1b laying arround. For 99% of the stuf it is too slow, but for this is was perfect. I installed it in my network rack. To save a RJ45 connection on the switch I added an usb network interface to the pi. This way it could be set “in series” with the cable.

The enclosure is one I 3d printed myself. At first I was searching for a din rail enclosure for the pi, but I could not find anything for the old version. Luckily I found these STL files.

The uploaded measurments can be found here:

Overview last few days:

Soldering Workbench

In my new workshop I needed a workbench. The one from the old shop was wallmount and too small. This gave me 2 options: buy a workbench or build a workbench. After a lot of searching I did not find what I was searching for.  It was either the wrong size, or too expensive or both. So the only option left was to build it myself.

First I made a drawing of how I want to build the frame:

To start the project I harvested the ugly ceiling trees that where in my living room.

I used a table saw to saw of 3 sides of the beams to clean them of glue and make the corners square. This gave me these beams:

To connect them together I used mortise and tenon connections in combination with wood glue.

Test without glue:

After this I could glue them together one section at the time beceause I did not have enough clamps to do more at once.


Section 2:

Section 3:

Section 4:

Test fit without glue of the front part:

Side piece glued:

Complete desk glued up:

Primer painted:

Painted Blue:

Time to make the desktop from MDF, also I installed the racks for the shelves:

Desk in place:

After a few weeks I came across an ad of a free desk frame with steel drawers. I dismantled the drawers and painted them black. These are now installed underneath the desk: (don’t mind the mess, the desk is in use for some time now).

On the next part I will show the LED desk lighting.

Going green (2)

In 2012 we put solar panels on the roof at my parents house. Link to the blog post. Now I have my own house it was time to put up my own panels. I chose again for bisol panels, this time 12x “Bisol Premium Bmo 320wp Full Black Mono” with a SMA STP 3.0-3AV-40 inverter.  Last time Elcubi did a great job, so I decided to also let them do this install.


The panels installed:

The inverter:

The power the installation produces can be looked at here:

Rapid CSN140 Electric Stapler Battery repair (B311 Battery)

I have a electric stapler that works with a battery. This battery became bad some time ago, after doing a lot of searching for a replacement battery.  I found none. I did not even find a reference to the battery. So time to fix it myself.

The battery Rapid Model B311:

The end of the battery pack is clicked into the bottom and can be taken apart by jamming a screwdriver in the seem:

Then this pack came out of the enclosure:

These are 3x 4/5 Sub-C 1100mA cells. To replace them I found N-1250SCRL cells from Panasonic at Reichelt. These cells have tabs attached that can be used to connect them.

For the positive terminal of the pack the tab welded to the cell can be used.  Between the cells I used solder to connect them together.

For the negative terminal the connections in between the cells are in the way, so I had to cut this bar and replace it by a wire.

Connection of the wire to the bottom:

This arrangement just barely fits inside the battery enclosure, when inserting make sure nothing is or can short circuit.

The last step is to reattach the end cap. It does not click in place anymore, so I used glue to attach it again.

And then the big question: Does it work? Yes it works:

Speakon Wall Connectors + Setup

For my living room I needed some speaker connectors in the walls. The power sockets I have are from the brand Niko, so I wanted the speaker connectors in the same look. However I did not like the look of those that are available, and therefore I made my own.

The base is made with a blind panel from Niko (122-76901).

In the center panel I drilled a hole with a step drill, and glued a 4pin speakon connector in the back of the panel:

At the amplifier I used an 8 pin connector. This one I did use screws since the force on the connector will be higher:


For the wiring I did a trick to have the speakers always wired correctly when the TV is moved. In the living room I have 3 positions I wanted to be able to place the TV.
Blue = TV; Black = speakers

In each setup I just want to plug the amp into the 8pin speakon and have the signals go to the correct speaker for that setup. This is done with some clever wiring. I gave each 8pin connector a number and each 4pin a letter:

This makes the connections this way:
Connector 1 Pin 1-2 -> Connector C
Connector 1 Pin 3-4 -> Connector D
Connector 1 Pin 5-6- > Connector A
Connector 1 Pin 7-8 -> Connector B
Connector 2 Pin 1-2 -> Connector E
Connector 2 Pin 3-4 -> Connector A & F
Connector 2 Pin 5-6- > Connector D &  G
Connector 2 Pin 7-8 -> Connector C & H

Radio flea market Bladel 2019

Today there was a Radio flea market in Bladel. I did not see much interesting stuff, so I bought very little.

What I bought:

  • Denon DCD-595 Cd player (that turned out to be defect)
  • DVD drive


The fault on the CD player was that the CD did not started to turn. After some searching I found out that this was caused by the player not seeing the CD. The lens looked pretty dirty, after cleaning with a cotton swab and some isopropanol I was left with 2 things. A very dirty cotton swab and a working CD player.

Radio flea market Diest 2019 (Dirage)

Today there was a Radio flea market in Diest.

What I bought:

  • DC jack power connector
  • Plastic enclosure with clear front
  • Bottle of flux


Radio flea market Turnhout 2019

Today there was a Radio flea market in Turnhout. What I bought:

  • Weller XXMP + tip
  • Aluminium plate 300x150x10mm

Radio flea market Bladel 2018

Today there was a Radio flea market in Bladel.

What I bought:

  • Calipers (old fashioned analogue one)
  • Bag din rail wire clamps
  • Bag rotary switches
  • Nixie frequency counter (Yes, I have a nixie addiction)
  • 2x 1GB DDR2 ram
  • 2x Surge protection module

Drain pump system

My new workshop is in my basement. For the hand washing / board cleaning “corner” this has the disadvantage that it is below the sewage level. In order to drain the water it needs to be pumped up. I had a few pumps from old washing machines laying around and decided to do some experimentation with this.

To make it easier for the pump (and to spare my back) I made a frame underneath the cabinets to raise the whole thing by 20cm. This way the water needs to be lifted less.

Normally there is a siphon after the drain in the sink, this part I have taken out and brought the pipe directly to the pump.

At the pump side the pipe goes down a bit in order to make the check valve work better (Picture further down on the page). Also because of this the sensor is not mounted at the lowest point. This makes it work better since the pump does not clear all the water from the pipes. The water that does stay in the pipe may false trigger otherwise.

However this means that the pump needs to operate longer when the sensor signal go’s off. Therefore I made a timer box. This was made with a Siemens LOGO The time is settable by a rotary switch. This switch is connected with a few inputs of the LOGO.

The pump:

The timer box:

The program in the LOGO!:

To detect the water in the pipe I used a E2K-L26MC1 capacitive sensor from Omron. This sensor can be clamped around the pipe and does not come into contact with the water.
The sensor cheapest supplier for this sensor,  I found on – Omron Level Sensor E2K-L26MC1 (Click-able Link)

This sensor has an NPN output, while the LOGO is only compatible with PNP output sensors. This I solved by adding a 10K pull-up resistor between out and +24V. After this the input needs to be inverted in the LOGO to work correctly (B17 in the program above).

Picture of the box and sensor installed: