I have some PIC18F4550s lying around, and I want to play with the USB features of this chip, therefore I made this breakout board. It contains enough components to get the PICMicro running, and nothing more, all the pins are routed to pin-headers to use with an experimenter board.


  • ICSP connector (In-Circuit Serial Programming, AKA PicKit 2 & 3)
  • USB-B Connector
  • 20Mhz clock crystal

Eagle files:  PIC18F4550 USB ICSP breakout board

Energia IDE

I never really caught on to the Arduino craze, not because of any dislikes as such, but because I was familiar with Microchips PICMICRO range. I had the parts, the programmer, and the knowledge to program them in both asm and C, so I guess I have had no need for the Arduino platform.

It turns out that the Arduino IDE has been ported to both the Stellaris Launchpad, and the MSP430 Launchpad from Texas Instruments. and is called Energia. This is nice, since it is then quite easy to port the vast amount of sketches and libraries from the Arduino IDE to Energia IDE and the Texas Instruments Launchpads.

Getting it going on Gentoo Linux

First to run Energia, 32-bit java support is needed, so


needs to be emerged. When running Energia you must make sure


is selected as user VM with eselect. Create a file called /etc/udev/rules.d/62-stellarpad.rules with these contents:

ATTRS{idVendor}=="1cbe", ATTRS{idProduct}=="00fd", MODE="0660", GROUP="plugdev"

Reload udev and add yourself to the "plugdev" group, plug-in in the Launchpad and you should be good to go!

While designing a fan control into another microcontroller project, I stumpled upon this nice design using only an external diode and capacitor. I used a 1N4148 standard diode and a 560pf capacitor.


I will walk through copying a bootable Windows 7 installation from a VirtualBox VM to real iron.

  • Insert an external hard drive in the USB port and share it with your Windows 7 VM.
  • Ask windows to make a system image "Control Panel -> Back up your computer -> Create system image", and save it to the external hard drive.
  • Boot the Windows 7 install disk, click through, and select "Repair windows installation". The drives that you do not put on the exclude list, will be repartitioned and formatted, so make sure to exclude everything you want to keep.
  • Let it chew on your backup, and when done, boot Windows.

Felt like doing a demo effect, I have done this once before in C and asm. The year was something like 1996, and the processor a Cyrix/IBM 6x86 120+. This is slooow, not only because it is written in Python, but because it isn't optimised.

Source: fdtunnel.tar.bz2

On Gentoo I needed to point the configure script at libbfd.so. On my system it is in /usr/lib/binutils/x86\_64-pc-linux-gnu/2.22/ hence:

./configure --prefix=/usr/local/ --with-bfd=/usr/lib/binutils/x86\_64-pc-linux-gnu/2.22/

It has been brought to my attention here that my instruction for building the Single ended class A headamp is not complete.

The transistors in the current mirror, and differential amplifier will benefit from having thermal contact, to keep the temperature difference as small as possible, thereby minimising the DC output offset. I have taken the best picture I could, of this coupling for one channel, in my amplifier.

Generated on 2017-10-10 09:11:09.636298