MatteoRagni / project.controller.interface

This is the source code for a controller for an Accumulator fatigue test bench based on Arduino. For DRTS S.r.l. (Interface library)

RPI Interface for project.controller

This is the interfacing library for the controller implemented in the project.controller repository. The interface is in C, for RaspberryPI using the wiringPI library.

Installation

Dependencies

1. sudo apt install build-essential git-core ruby ruby-ffi
2. wiringPi (follow installation instruction from the project page)

Compile

make shared

Communication object

The Ruby Object SerialComm allows a very simple communication with the device. When the object is created, it connects to the serial port specified as argument:

sc = SerialComm.new("/dev/ttyACM0")

the port is automatically closed when the GC frees the memory. The current information must be requested to the remote device with the sc.update() method, and it will require some time to receive all the information (at least two loops of the controller, meaning 60ms).

The write operations are:

• sc.t_set = 0.0: temperature set point
• sc.p_high = 0.0: pressure top value
• sc.p_low = 0.0: pressure bottom point
• sc.PI_kp = 0.0: pressure PI control proportional gain
• sc.PI_ki = 0.0: pressure PI control integrative gain
• sc.p_set = 0.0: pressure current set point
• sc.period = 0.0: square wave pressure period
• sc.duty_cycle = 0.0: square wave pressure duty cycle
• sc.cycle = 0.0: number of cycle performed
• sc.cycle_max = 0.0: maximum number of cycle to perform
• sc.toggle_chiller: chiller toggle enabling bit for temperature control
• sc.toggle_resistance: resistance toggle enabling bit for temperature control
• sc.toggle_actuator: actuator toggle enabling bit for pressure control

The read operations are (as floating point values):

• sc.t_meas current measured temperature
• sc.p_actuator_meas: measured actuator pressure
• p_accumulator_meas: measured accumulator pressure
• PI_kp: current pressure controller proportional gain
• PI_ki: current pressure controller integrative gain
• t_set: current temeprature set point
• p_set: current pressure set point
• u_pres: current input from PI for pressure
• duty_cycle: current duty cycle value
• sc.cycle: number of cycle performed
• sc.cycle_max: maximum number of cycle to perform

(as boolean values)

• sc.chiller: chiller enabled for temperature control
• sc.resistance: resistance enabled for temperature control
• sc.actuator: actuator enabled for pressure control

(as code symbol)

• sc.state: execution state of the controller
• sc.error: error code of the controller (error string in sc.error_string)

The EEPROM operations are

• sc.save_config: save configuration in the EEPROM
• sc.load_conf: load configuration from the EEPROM
• sc.load_cycle: load cycle value from the EEPROM (written automatically)

The Execution commands are:

• sc.play: run the cycle
• sc.pause: pause the cycle
• sc.stop: emergency stop

The example

The example main.rb, with the SIL_SIM option in the firmware, generates the following output: