Tuesday 22 November 2016

Test your USB serial converter

Back in the days

when PCs came with serial and parallel ports, techs had sets of plugs to test the serial and parallel interfaces with.

There is also a >>>video<<< on this!


I still use a RS232 adapter on my SurfacePro at work to configure Cisco network components. I had quite a few of these for the last few years with different chip sets.

For my microcontroller hacking joy, I have come to like CP2102 based adapters like this one. The chip is 5V tolerant and puts out 3.3V levels which is good enough for 5V applications, too.

Put it to the test

Sometimes, when stuff doesn't work as expected, I wonder: Does my USB-serial adapter even work? And the test is easy:
Simple loopback
On this adapter, we don't have any additional signal lines that we find on a fully featured adapter, so all we have to do is to connect the TXD pin to the RXD.
Now everything transmitted through the TXD pin is fed back to the receive pin.

If the driver installed ok, you will see a new COM Port. In this case: COM3

For the loopback test, you have to configure that COM-Port into Putty:
Configure Putty
By default, Putty has local echo off. That means that if you press a button on the keyboard, you will see nothing, unless something is sent back by the adapter.

If you see what you type, everything is ok:

No local echo

If you enable local echo (tick "Force on"),

Enable or disable local echo
you will see every keystroke twice:
With local echo
And that also means that your adapter works ok.

Materials used in the video and for the blog entry:

Thursday 17 November 2016

Getting started with a Samsung Portable SSD T1 (500GByte)

For my wife's macbook, I was looking for an new external 500GByte USB-SSD drive. She had filled an external 256MByte Transcend SSD with her iPhoto library and now it was time for the next step.

I found a very reasonably priced, now discontinued Samsung Portable SSD T1 (Model MU -- PS500B) at a nearby consumer electronics store. Manufacturing date is 03/2015. Not the latest&greatest, but for 129€, it seemed like a bargain. Worth a try.

From the comments on Amazon, I knew that installation was not painless and many had complaints. So I decided to "unlock" the drive on my Windows 10 PC and re-format it on the MacBook later.

In Windows 10 the drive did not show up with a driver letter, so I couldn't install the software required to unblock the drive. I had expected to see a "tools"-Partition or something like that
The manual was not helpful either.

There is a new drive!

But it looks pretty useless

No tools or utilities partition and no driver CD in the box. Gooooogling helped:

I found the T1 Activation Software here.

I then extracted "SamsungPortableSSD.exe" from the ZIP Archive and ran it.
I choose not to use a password and a few moments later, the drive was accessible:

exFAT... Ugh!
Reformatting to NTFS was quick and painless. The SamsungPortableSSD tool did not seem to leave unwanted stuff on my system.
Re-formatted to NTFS
It is now possible to partition  / format the drive on the MacBook with a HFS file system. No need for stuff that hooks into OSX.
Shows up as expected
Re-formatting to HFS is easy.
Yes, we're sure!
Now that wasn't too hard, although Samsung didn't really make it intuitive. And that might be the reason why I got this drive for cheap.