Evolution of a Blog

This blog has evolved as I have as a maker. It starts at the beginning of my journey where I began to re-tread my tires in the useful lore of micro electronics and the open-source software that can drive them. While building solutions around micro-electronics are still an occasional topic my more recent focus has been on the 3D Printing side of making.

Wednesday, August 14, 2013

Prototype Hardware - BeagleBone Black and Raspberry Pi

Here are pictures of the hardware for the prototype of "The App" that I am building.  As you can see the BeagleBone Black is sporting an LCD while the Raspberry Pi is not.   On the other hand, the Raspberry Pi is decked out with a little joystick which the BeagleBone Black is missing.

The components that are shared by both computers are the:
  • Real Time Clock (RTC)
  • Analog Digital Converter (ADC)
  • Variable Resistor
The wiring for RCT and ADC are discussed in an earlier post.    The variable resistor is part of a voltage dividing circuit that takes five volts and delivers a variable 0 to 2.5 volts as a simulation of the lab equipment 'The App' will talk to later.

The LCD display on the BeagleBone Black is the 3.5 inch cape (LCD3) from Circuitco.  It presents the Beaglebone Black's console in 320 by 240 pixels of resolution.  'The App' is presented by Chromium running in full screen kiosk mode and looks very sharp.

The 5v power supply from the Raspberry Pi is used for the simulated instrument while an external power supply is used in the case of the BeagleBone Black as it delivers a more stable voltage.

Finally, the Raspberry Pi has a joystick attached as a possible option for user input.  It is attached to the ADC with two outputs delivering a voltage from -2.5 to +2.5 representing each of the two axis.   In addition there is a line to a GPIO pin, attached to a pull down resistor, to register a click.

Monday, August 12, 2013

Using the uSD on BeagleBone Black as Aux Storage

I followed some instructions, that I have since lost track of, to enable the use of the uSD card on the BBB for auxilary storage when booting from the internal eMMC.   The below are my version of what was needed:

Format the drive
Add a partition and make it of type FAT, name it and size it however you want
After it has been formatted and partitioned mount the FAT 32 partition you just made
Create the document "uEnv.txt" in the root of the partition and add the following lines to it:

mmcroot=/dev/mmcblk1p2 ro

This should do it.