Thursday, September 5, 2013

Robotic power supplies and Raspberry Pi USB controller!

I haven't posted here in a while since I  have not played with my Raspberry-Pi much.  I have been working on a couple arduino controlled robots and this week I made a nichrome plastic bender that is powered by a computer atx power supply that was converted into a robotics lab power supply with extreme accuracy in 1.25-11 volts DC using a LM350 voltage regulator IC.  I'll add some pictures of that below. 
  I had planned to add my Raspberry Pi to the Arduino robot via I2C and a level shifter.  But I think I may have found a way to make the RPI have more direct control.
 Above is a USB controller kit with 5 digital,  2 analog inputs, 8 digital outputs and 2 analog PWM outputs.  I may still need to connect the arduino to the RPI's gpio port and have certain real time events handled by the 328p (rpi time slicing under linux leaves a lot to be desired for real time IO.)
  The USB experimentation interface kit is made, by Velleman and is model k8055.  This is the kit, so solder/assembly skills are required. There is an assembled kit also available from velleman.  This is made for the windows platform.  But as I understand it, there are libraries written for Python (and other languages) and there are system hacks to connect it to the Raspberry Pi.   As soon as I have mine assembled,  I  will post the exact methods I use to get it running under the Raspbian OS on the RPI! 
  I think I  will start using the blog for ALL of my robotic/electronic experiments,  since the rpi is only a fraction of what I am involved in.  It will mean a lot more info and posts will be shared.  Now onto the fun stuff,  here are some more pictures of the lab power supply and voltage regulator I am just completing. 
The LM350 variable regulator ready to be connected to the lab power supply. 

Converted ATX power supply to a robotics lab power supply.  Banana plug connectors are GND x2, -12v, -5v, +3.3v, +5v and +12v DC. The LM350 is connected to gnd and +12v and provides any voltage from 1.25 to 11v Dc with up to 3 amps current.  It could also be connected to any of the other voltage plugs if I  needed the 12v as well as a lower voltage at the same time.  (why I used 2 grounds).  Example,  12v motor supply and a 3v regulated MCU supply.
  If you want to know more about any of these projects, leave me a comment and I will be happy to share.  (spams are deleted!)