Benoit Frigon
My blog about electronic projects, telephony and other stuff...

SSH login without password?

Posted on Apr 02, 2014  - Last updated on Dec 30, 2018

If you need to manage multiple servers, having to re-enter your password each time you want to establish an SSH connection can become tedious. There is a better way. It is possible to initiate an SSH connection by using a public/private key pair instead. The main advantage is that you can use this key on multiple accounts and only need to remember the pass-phrase of your key.

Continue reading...

ASM delay subroutines for PIC16 mcu

Posted on Feb 14, 2014  - Last updated on Dec 10, 2018

These are the delay subroutines i use in my PIC projects. It was written for the PIC16 family but should be compatible with the 18F instruction set as well.

The simplest way to produce delay is to write a subroutine that waste instructions cycles for the desired amount of time. This method should not be used for application that require a high level of precision since the delay subroutine may be halted by interrupts. The delay is offset by the time it takes to execute the interrupt service routine. For short delays however, this should not be a problem.

Continue reading...

LED strip lighting for my a/v rack cabinet

Posted on Oct 23, 2013  - Last updated on Dec 10, 2018

I installed a LED strip in my a/v rack to make it easier to see when I’m working on it. My plan was to buy white LEDs but it turned out to be cheaper to get RGB strips of the length I needed where I bought them. The kit comes with a controller and a remote control which allows you to set the intensity and change colors.

Continue reading...

Linux alarm clock

Posted on Oct 07, 2013  - Last updated on Dec 10, 2018

I’ve been working on this project for some time now. This is my alarm clock running Linux.

These are the feature I wanted:

  • NTP time synchronization
  • Touch keypad
  • Transparent seven-segment display
  • Web interface to configure the clock, upload alarm sound, etc.
  • Battery backup
Continue reading...

Custom 19 inch rack cabinet

Posted on Aug 12, 2013  - Last updated on Dec 10, 2018

This is the rack cabinet i made for my a/v and network equipment. The cabinet is 75.5”H x 20.5”W x 19”D and consist of 3 sections, the 2 upper sections are 19-1/8” wide rack mount space and the lower section is a 16” height compartment to store my UPS. There are 18 units of rack space in the middle section and 12 units in the upper section.

Continue reading...

Recording voice prompts with Audacity and SOX

Posted on Jul 27, 2013  - Last updated on Dec 30, 2018

Asterisk comes with an extensive set of voice prompts in many languages but there are situations where you may need to record your own voice prompts. It can be tricky to get it right. This article describes the method I use to achieve that. I use Audacity and SOX to record and convert the voice prompt files.

Continue reading...