Arduino based Blend Micro gives error: Device Descriptor Request Failed in Device Manager

September 6, 2014

So I started to fiddle around with the Red Bear Lab Blend Micro. All seemed ok, but after I had uploaded a sketch, the device stopped being recognized properly.

The Device Manager in Windows gives me an error message saying Device Descriptor Request Failed:

Device Descriptor Request Failed

Device Descriptor Request Failed

Well, several other blog posts suggests that re-installing the device drivers will help. But that’s really not helping.

The issue seems to be that the device is not responding and communicating properly with the connected USB host for whatever reason when the sketch is running. Let’s see if we manage to revert back to an empty default sketch. The Blend Micro device has a window of 8 seconds from booting until it starts running the loaded sketch. During that time frame, we should be able to upload a default sketch.

First, make sure that the Blend Micro is the selected board in the Arduino IDE:

Blend Micro is selected

Blend Micro is selected

Prepare a sketch with the base minimum code:

Then reboot the Blend Micro device by pressing the reset button.

Reset button on the Blend Micro

Reset button on the Blend Micro

The timing can be critical, so you probably have to try multiple times to get it right. A tip is to click the Upload first, wait a half of a second and then press the reset button.

 

How to hide the status bar in iOS 7 using Xamarin Forms

August 23, 2014

In order to hide the status bar, one has to add 2 properties in the Info.plist file.

Edit the file and switch to Source view.

Add an entry named UIStatusBarHidden and set the value to true.

Add an entry named UIViewControllerBasedStatusBarAppearance and set the value to false.

The UI editor will translate these into Status bar is initially hidden and View controller-based status bar appearance respectively.

HideStatusBariOS

HideStatusBariOS

How to install VNC server on Raspberry PI

August 5, 2014

This is a short note on how to install VNC server on Raspberry PI.

Raspberry PI B+

Raspberry PI B+

Step 1

The VNC server is not installed by default in Raspbian, so first install using apt-get:

Step 2

Make a script file to start the VNC server:

Enter the following:

Save the file; Ctrl+o , Enter and the Ctrl+x.

Step 3

Make the file executable:

 
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