Category Archives: Projects

OPP: ChameleonPi

You are now basically obligated to pick up a Raspi.  Chameleon is a Raspian “Wheezy” remix which includes almost every video game console emulator you’d ever want.  Easily drop a few roms in your pi via your desktop’s network browser and you’re quickly reliving every priceless moment in The Legend of Zelda or Super Mario, or just get a gentle game of pong going on.

From Carles Oriol:

Comprehensive instructions on how to flash an SD with ChameleonPi (8GB minimum):
http://www.stefanopaganini.com/raspberry-pi-chameleon-overview-and-tutorial/

CameleonPi Homepage:
http://chameleon.enging.com

I experienced quite a bit of lag using the NES emulator until I over-clocked the CPU.

To check your current clock speed:

vcgencmd get_config arm_freq

or for more detailed information:

vcgencmd get_config int

You can edit the config file directly:

sudo nano /boot/config.txt

or use the raspi-config tool to set basic over-clocking:

sudo raspi-config

Scroll down to option 7 – overclock.
I chose “High” 950MHz ARM, 450MHz core, 450MHz SDRAM, 6 overvolt.
So far it’s running smooth with these settings.

My next step will be to figure out how to only display the emulators that I choose in the UI in hopes of simplifying the interface for less experienced, and younger users.  I think machines.conf file has something to do with it so I’ll make a backup copy and start messing around with it:

sudo cp /opt/selector/machines.conf /opt/selector/machines_orig.conf
sudo nano /opt/selector/machines.conf

Stereo Amplifier

My second attempt at mastering the LM386 Audio Amp IC (still sounds terrible).P1020890

 

Here’s the data sheet for the LM386 IC with some example circuits:
http://eicom.ru/pdf/datasheet/National_Semiconductor_PDFs/LM386/LM386.html

Instructables has a simple how-to:
http://www.instructables.com/id/LM386-Audio-Amplifier/

The schematic used in my project is a variation of this one from:
http://www.rason.org/Projects/icamps/icamps.htm
The only difference is that I added a 100nF from pin 7 to ground.  I think it helps keep the noise down.  There’s also two of everything except R1 and C1.

IMG00001

P1020902 P1020916
P1020911 P1020905
P1020904 P1020914

Wow, my wires are all way too long.  It makes it very hard to get into a tiny box, but it works!