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

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:

void setup() {
// put your setup code here, to run once:
}
void loop() {
// put your main code here, to run repeatedly:

}

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

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

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:

sudo apt-get install tightvncserver

Step 2

Make a script file to start the VNC server:

nano startVNC.sh

Enter the following:

#!/bin/sh
vncserver :0 -geometry 1920x1080 -depth 24 -dpi 96

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

Step 3

Make the file executable:

chmod +x startVNC.sh

How to install VNC on Beaglebone Black

Beaglebone Black

A short step through on how to install VNC on Beaglebone Black.

Step 1.

SSH into your Beaglebone.

ssh [email protected]

(Or whatever your BBB IP address is)

Step 2

Install x11vnc.

Angstrom:

opkg install x11vnc

Debian:

sudo apt-get install x11vnc

 Step 3

Start the VNC server

Angstrom:

x11vnc -bg -o %HOME/.x11vnc.log.%VNCDISPLAY -auth /var/run/gdm/auth-for-gdm*/database -display :0 -forever

Debian:

x11vnc -bg -o %HOME/.x11vnc.log.%VNCDISPLAY -auth /var/run/lightdm/root/:0 -forever

 Step 4

Create a script file to make life easier to start the VNC server.

nano startVNC.sh

Add this to the file:

#!/bin/bash
x11vnc -bg -o %HOME/.x11vnc.log.%VNCDISPLAY -auth /var/run/lightdm/root/:0 -forever

Save the file using commands Ctrl+o press Enter and the Ctrl+x.

Make the script executable:

chmod a+x startVNC.sh

Execute the script:

./startVNC.sh