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Epson XP-205 Scanner in Windows 8.1 – How to get it back to work

Now it’s time for a Epson XP-205 Scanner to work with Windows 8.1

It took me a while now to get the XP-205 scanner component to run on my new Windows 8.1 via WiFi:

The problem is, that when you install the scan software, you might get a communication error telling you that the scanner is probably not connected or turned off. Both of course is not the problem.

So how you get it online in Windows 8.1:

First install the Epson Scan software that you can obtain directly from epson (german version link).
Open the scan software and verify that you (still) get the error.
Then change to the Windows-Tile screen (just hit the Windows-Key on your keyboard) and type “Epson Scan”. A list should appear that shows the Epson Scan entries. One of them should be “Epson Scan Settings” (german: Epson Scan-Einstellungen).
Now comes the tricky part:If you work as an administrator (which you shouldn’t do usually), just open the Epson Scan Settings tool. Otherwise right-click the Epson Scan Settings tool and start it with administrator privileges. This is very important! Otherwise you won’t be able to do the next step as an important part is greyed and thus unavailable!
You should see the settings window with “Connection local” selected.
Hit the “Network” button and then hit the “add” button below the Networkscanner address field.
If this button is disabled, you probably do not run the program with admin privileges.
Add the Scanner’s IP and give it a name.
Hit the Test button – it should work now!

The scan software should work now. I first had some issues that I also had to run it with admin privileges. Sometimes I could start the scanning software, showing the correct user interfacec but it only scanned a very tiny part of the physical scan area (VERY strange).

So if you still experience some issues: Try restarting the computer first! If this doesn’t work, try starting as administrator.

Update: The Scan software surprised me today with a message similar to “ah no – I won’t scan today”. So I

uninstalled the scan software. Well I tried, the files were still in the windows directory.
let the Software updater update the firmware of the device
reinstalled Epson Scan

And – suddenly everything is just fine.

How to fix Twitter share button in WordPress’ Huge-IT Share buttons

I just tried the Huge-IT share plugin for wordpress and realized that the twitter share button seems to have a bug: When sharing, the tweet will not link back to the URL. Not cool :-/

Fix:

changed the file (via edit plugin): wp-share-buttons/Front_end/share_front_end_view.php

case 'share_twitter_button':
 $link= 'https://twitter.com/intent/tweet?url=http%3A%2F%2F'.$linkthispage.'&text='.$str;

Now the URL is prepended with http and thus displayed in the twitter share-dialog as well. Mission accomplished.
(And Huge-IT is also informed about the bug + fix)

Have fun and a happy new year

Check internet connectivity in Android

When programming an Android App you sometimes want to check, if you are connected to the Internet.
The first thing that comes to mind is using the ConenctivityManager. Yet this solution has the problem that it only tells you that you are connected to .. something. With a WiFi connection this can mean, that you are connected to an access point. But it does not tell you that the access point is connected to something else!

Continue reading Check internet connectivity in Android

Scalding hiding NPEs in “operator Each failed executing operation”

Yesterday I was surprised by a failing Scalding task. Everything worked fine locally and all I git was like “job failed, see cluster log”. In the cluster log I saw the following:

2014-10-24 14:38:41,222 INFO org.apache.hadoop.mapred.TaskInProgress: Error from attempt_201410101555_2230_m_000005_3: cascading.pipe.OperatorException: [com.twitter.scalding.T…][com.twitter.scalding.RichPipe.each(RichPipe.scala:471)] operator Each failed executing operation
at cascading.flow.stream.FunctionEachStage.receive(FunctionEachStage.java:107)
at cascading.flow.stream.FunctionEachStage.receive(FunctionEachStage.java:39)
at cascading.flow.stream.FunctionEachStage$1.collect(FunctionEachStage.java:80)
at cascading.tuple.TupleEntryCollector.safeCollect(TupleEntryCollector.java:145)
at cascading.tuple.TupleEntryCollector.add(TupleEntryCollector.java:133)
at cascading.operation.Identity$2.operate(Identity.java:137)
at cascading.operation.Identity.operate(Identity.java:150)
at cascading.flow.stream.FunctionEachStage.receive(FunctionEachStage.java:99)
at cascading.flow.stream.FunctionEachStage.receive(FunctionEachStage.java:39)
at cascading.flow.stream.SourceStage.map(SourceStage.java:102)
at cascading.flow.stream.SourceStage.run(SourceStage.java:58)
at cascading.flow.hadoop.FlowMapper.run(FlowMapper.java:130)

Continue reading Scalding hiding NPEs in “operator Each failed executing operation”

Enable output compression in Scalding

I just wanted to enable final output compression in one of my Scalding jobs (because I needed to reorganize a some-TB-data set).

Unfortunately scalding always produced uncompressed files. After some googling, I came across a github issue that adressed exactly this problem. Via some links I got the sample code from this repo which can be used to write compressed TSVs.

Continue reading Enable output compression in Scalding

Scalding Exception: diverging implicit expansion for type com.twitter.algebird.Semigroup[T]

I was just doing a again some scalding jobs and again got an .. interesting exception:

In a groupBy operation, I wanted to sum something up using:

.groupBy('a) {
  _.sum('a -> 'c)
}

And was rewarded with this one:

[error] example.scala:20: diverging implicit expansion for type com.twitter.algebird.Semigroup[T]
[error] starting with method eitherSemigroup in object Semigroup
[error]       _.sum('a -> 'c)
[error]            ^
[error] one error found
[error] (compile:compile) Compilation failed

WTF??

Solution:

Spot the mistake? It’s the missing type hint at sum:

.groupBy('a) {
  _.sum<strong>[Int]</strong>('a -> 'c)  //  <-- [Int]
}

Scalding: unable to compare stream elements in position: 0

I’m currently working quite a bit with Twitter’s Scalding.
Recently I split up a job into sub-jobs and suddenly got an Exception in my join:

Caused by: cascading.CascadingException: unable to compare stream elements in position: 0

If I had remembered the Fields API in detail, I would have thought about this paragraph (it’s about sorting, but the consequence is the same):

Note: When reading from a CSV, the data types are set to String,hence the sorting will be alphabetically, therefore to sort by age, an int, you need to convert it to an integer. For example …

Solution:

Ensure you are joining the correct data types and possibly convert them before. For example:

.map ('myField-> 'myField) {x:Int => x}

Enable MySQL Streaming in Cascading / Scalding

Last week I ran into a an ugly problem of Scalding:
I needed to read a really large table from MySQL to process it in a certain job. In generall this is trivial: just use a JDBC Source, select your columns and that’s it.

Usually we do this by using 1-3 parallel connections to the SQL-server. This time I started running out of memory because scalding didn’t (more precicely: couldn’t) swap/spill to disk. The problem here is the default behaviour of the mysql-connector. The api docs says:

By default, ResultSets are completely retrieved and stored in memory. In most cases this is the most efficient way to operate, and due to the design of the MySQL network protocol is easier to implement. If you are working with ResultSets that have a large number of rows or large values, and can not allocate heap space in your JVM for the memory required, you can tell the driver to stream the results back one row at a time.

So, what does this mean: If you query a 10 GB table, you get all the data and the connector tries to buffer it in memory – which is a bad idea if you just want to process tuple by tuple. You can then split this large query into 10 smaller ones: SELECT ... FROM ... LIMIT 0, x, SELECT ... FROM ... LIMIT x+1, y, … etc. This works – but partitioning a large result this way is not very efficient because starting from the second query, MySQL has to iterate over x rows until it can start gathering and returning results. So you partition the big query into 10 smaller results but you put quite a lot of load to the server. And over all you still have to keep a lot of results in RAM.

Continue reading Enable MySQL Streaming in Cascading / Scalding

Compiling Cascading: FAILURE: Build failed with an exception.

Today I ran into a really stupid error message when I tried to recompile cascading-jdbc:

Evaluating root project ‘cascading-jdbc’ using build file ‘/home/…/cascading-jdbc/build.gradle’.

FAILURE: Build failed with an exception.

* Where:
Build file ‘/home/…/cascading-jdbc/build.gradle’ line: 68

* What went wrong:
A problem occurred evaluating root project ‘cascading-jdbc’.
> Could not find method create() for arguments [fatJarPrepareFiles, class eu.appsatori.gradle.fatjar.tasks.PrepareFiles] on task set.

* Try:
Run with –stacktrace option to get the stack trace. Run with –debug option to get more log output.

BUILD FAILED

Total time: 5.355 secs

Solution

Check your gradle version … I ran a brand new Ubuntu with the shipped gradle version 1.4. Well the cascading readme states that gradle 1.8 is required … and it really is.

RaspberryPi Desktop Sharing via VNC

The problem: Raspberry connected to a TV / share the desktop

When connecting a RapsberryPi to a screen or TV to show something you surely would like to remote control the RasPi not only via shell (SSH) but also via VNC to see exactly what is displayed on the remote screen. So what we are looking for is not “a new remote desktop” (as provided by a lot of tools) but “desktop sharing”. And of course you want the desktop shared automatically when the Raspberry Pi boots.

Yet thanks to the great and large Rapsberry Pi community, this is a pretty easy task – if you know how to do it …
Continue reading RaspberryPi Desktop Sharing via VNC