Basic Functioning of Phoenix Interface


Hardware  Features
  • 4 Analog Inputs (10 bit resolution)
  • 1 Analog Output ( 8 bit)
  • 4 Digital Inputs
  • 4 Digital  Outputs
  • Frequency Counter
  • Square  wave generator
  • Constant Current Source  (1 mA)
  • 2 Inverting Amplifiers  (gain set plugin resistors)
  • 1 Non-inverting Amplifier
  • 2 Level Shifting Amplifiers
  • RS232 / USB interface
  • ATmega16 micro-controller
    Phoenix provides Analog and Digital Input/Output capabilities to a computer through the sockets on the top panel. Experiments are designed utilizing these I/O capabilities and suitable sensor elements to convert physical parameters into voltage signals. The program running on the micro-controller makes the measurements as per the commands send from the PC through RS232 or USB links. Users can access all these features by calling functions from a Python library. Python language is chosen due to its simplicity and ease of doing scientific computation and graphics using it.
     The figure shows a solenoid connected to the first Analog Input channel through a Level Shifting Amplifier. When the magnet is driven through the coil a voltage will be induced across the coil, which may go to both positive and negative values. The velocity of the magnet is chosen so that the peak voltage remains below 5V. The level shifting amplifier  converts the -5V to 5V signal to a 0 to 5V signal , that is required for the analog input. To view a screenshot of the experiment capturing the waveform click here.


RS232 and USB Versions
    The RS232 version require a 9 pin serial port on the PC. The serial versions can be used with RS232 to USB adapters.


Smaller Version (Phoenix-MDK)  
The smaller board shown in the figure is a minimal version of Phoenix. The 2 mm round sockets, plastic casing and the op-amp circuits are not there in this version. This board is sold by Phoenix vendors at US$ 20/-.
 All the Phoenix programs can be run from this board also. This board can be used as a micro-controller development kit. The python program logger.py ( also require draw.py ) converts this board in to a data logger. A screenshot of it is here.

Parallel Port Version
    The first version of Phoenix was interfaced to PC Parallel port. The hardware is accessed through a special device driver and the time interval measurements are done by the driver. There is no micro-processor in this design. It still works from the Phoenix Live CD version 3.xx (Not from 4.xx).