Fast SSD with NVMe

NVMe is the abbreviation for “Non Volatile Memory Express” and describes a standard for connecting SSDs via PCI Express. With SATA the speed is limited to 600 MB/s. In addition, AHCI (Advanced Host Controller Interface) used by SATA was primarily developed for hard drives and limits the possible I/O operations per second (IOPS). With NVMe both have been improved – PCI Express enables significantly higher transfer rates of up to 32 GBit/s or 4 GB/s via PCIe 4x and more than 500000 IOPS.

After one of the SSDs in my “retro PC” started reporting checksum errors I installed an NVMe drive with a PCIe adapter card for M.2 as a replacement.

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First Covid 19 vaccination

Two days ago I received my first Covid-19 vaccination in a vaccination center in Berlin. I got Comirnaty from BioNTech as a vaccine. The whole process was organized very professionally – I came straight to the admission without queuing and it took a total of maybe 20 minutes until the actual vaccination. After that I had to stay in the waiting area for 15 minutes so one can react immediately to any severe vaccination reactions – which I didn’t have.

During the first few hours after the vaccination, I got a slight headache that lasted until the next day. I was also quite exhausted so I went to bed in the afternoon. The the left arm where I got the injection was a bit painful until the next day, but only when touched directly. Overall, however, the side effects were quite bearable and today, on the third day, the headache is completely gone and I can feel the pain on my left arm only very slightly and expect this to go away completely tomorrow as well.

My little “electronics lab”

Some time ago I rediscovered my interest in electronics and recently done my first project. This project was created at the table where my PC is. However, this is not an ideal place to solder circuit boards or create designs with breadboards – I have to take the necessary parts and tools such as soldering iron, multimeter, etc. out of the drawer and then tidy up again afterwards.

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HDSP-211x for Raspberry Pi

On the project page about using LED matrix displays of the type HDSP-212x, I also showed an example setup with a Raspberry Pi. Now that I still have some of these displays, I would like to use them to build a real device in its own case.

Soldering the whole thing by hand on a perfboard would theoretically be possible, but is prone to errors and in the end you have only one copy. Nowadays there is a better solution for this: you design a circuit board with a program like KiCad and have it produced as a small series for comparatively little money.

My first draft for a board on which you can put four HDSP-211x next to each other already looks quite promising:

At AISLER, the production of three copies would cost around EUR 25 and would be ready in about a week. But before I actually do this, I’ll have to check the circuit diagram again and check whether adjustments are required for the power supply, since four modules together can have a power consumption of more than 1.6 A.

Revision 2

After taking a closer look at KiCad, I created a revised revision 2 of the layout:

  • The total size of the board is a bit smaller.
  • The mounting holes are now inserted as footprints and without soldier mask.

Controlling a HDSP-2112

“I’ve created fire!”

The HDSP-2112 is a module with a LED matrix display which displays 8 characters with 5×7 LEDs each. Due to the high power requirement of more than 2 watts this display is not suitable for mobile devices. The operating voltage is 5 volts and it will be controlled using a 8 bit wide data bus and a 5 bit wide address bus.

I already experimented with this in 2013, however I stopped working on that and did not have a working setup ever.

This time I was more persistent – and it worked :-).

HDSP-2112, test with Raspberry Pi

More about this along with a thorough documentation on the project page.

By the way – about USB controllers

My PC is built into a tower case from Chieftec. This case offers also external ports for USB 3 among other things. Internally, these ports are connected to the mainboard.

However, I also installed an internal memory card reader from Chieftec, which also uses USB 3 and offers a 4× USB hub. This means that the only internal USB 3 port on the mainboard is occupied. In order to be able to use the external USB connections, I bought an additional controller for PCI-Express, which offers two external USB connections and two more internal connections. The connections in the housing can also be supplied via this.

So far so good – but there was a strange effect when I tried to use a Velleman K8055N: as soon as the connection was established in the software, the software stopped working. This effect did not occur using the connections of the mainboard itself. The USB connections of the memory card reader were not a problem either.

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Juan Joya Borja is dead

The spanisch comedian Juan Joya Borja, who is also known as “Risitas” or “El Risitas” – “the giggling”, has died at the age of 65 in a hospital in it’s hometown Sevilla according to a report in the spanish media.

Juan Joya Borja became famous by a video meme which was used in many variations with different subtitles: