Month: March 2014

How to set your Raspberry Pi Screen Resolution

Previously my monitor could not support HD display and it looks awful. So I decided to turn on the safe mode for HDMI. It’s a headache because the font size is big and everything on the page is big. Recently I was using the monitor in the lab and I finally thought of changing the setting. So here’s what I did.

1. Get the list of what’s supported by your monitor:

tvservice -d edid
edidparser edid

2. There are a few modes in the resulting list. Choose one that you want. (For me, i chose DMT (35) 1280x1024p)

3. Edit the config file:

sudo nano /boot/config.txt

Comment out safemode.

Find the section about HDMI, uncomment it and set the right group and mode from step 2. If your mode description contains “DMT”, the group should be 2, and if it contains “CEA”, it should be 1, so for me that was:

# Set monitor mode to DMT
# Set monitor resolution to 1280x1024p 60Hz

Exit the editor with CTRL+X, followed by Y.

4. Reboot:

sudo shutdown -r now


Raspberry Pi desktop screenshot

Raspberry Pi desktop screenshot



Changing Password for phpmyadmin on Raspberry Pi

I happen to forget my password to phpmyadmin because it was months ago since i installed it with my Apache2 web server. I did a quick search on the net and found a forum post discussing about recovering password for phpmyadmin on XAMPP. I haven’t try this on Raspberry Pi because I managed to recover my root password. (username is root!) However this may be useful for future reference:

You may want to edit this file: “\xampp\phpMyAdmin\” for XAMPP on desktop or “/etc/phpmyadmin/”

change this line (for XAMPP):

$cfg[‘Servers’][$i][‘password’] = ‘WhateverPassword’;

to whatever your password is. If you don’t remember your password, then run this command in the Shell:

mysqladmin.exe -u root password WhateverPassword

where ‘WhateverPassword’ is your new password.

However I couldn’t find the line for Raspberry Pi. Instead, this may be helpful:
/* Uncomment the following to enable logging in to passwordless accounts, after taking note of the associated security risks. */
// $cfg['Servers'][$i]['AllowNoPassword'] = TRUE;

How to do Raspberry Pi Backup

It is really important to do back up to your SD card because anymore addition or configuration will cause your previous configuration state to disappear and you have to redo everything!

I am in the state where I am partly successful with my experiment but unhappy about the framework used. So it’s time to do a back up and modify the files in the card for my new experiment.

I thought I have written a post regarding this but it seems like I have not. So, just for my future reference, here are the steps to do the back up. It’s pretty simple.

  1. If you are using Window, download Win32 Disc Imager (win32diskimager-v0.9-binary) here.
  2. Unzip the file and open the “Win32DiskImager” application.
  3. To write a back up file to your laptop/ PC, select the location where you want the backup file to be by clicking the “open file” icon. WARNING: it is going to be the size of your SD card, e.g 8Gb for my case.
  4. Type in a name for your backup file. Check that everything is correct.
  5. Click Read.

It takes a while to complete. Once it is done, it will prompt you and “Done” will be written at the bottom left.



To write a backup file to your SD card, do the same thing. Select the back up file and right device, click Write. This will overwrite the SD card with the backup image.