uEACos Command Specification

Overview

The uEAC hybrid computer is designed to explore novel paradims in the area of analog computation. The analog backend of the machine is augmented with a ucontroller interface. The ucontroller utilized is the MSP430F169. The communication with the host is implented with an FTDI2232C usb controller. The FTDI chip provides a virtual serial port interface.
To communicate with the uEAC, a serial console program such as hyperterminal can be used to send command strings. These strings are used to configure the analog circuitry of the system. The serial console program should be configured as follows 19200 baud (8N1).
Each newline-terminated command is broken into fields that are delimited by a comma. When a command is accepted, the uEAC will return "OK". If the command is not accepted, the ueac will return "NOK". The commands are not case sensitive and the fields can have embedded spaces.
For commands that operate on a particular pin, the pins are numbered by x,y pair. Where pin 1,1 is in the upper left corner of the board. Pin 5,5 is in the lower right corner of the board.

Commands

Read All

Command returning reading from all 25 probe sites. If voltage mode is sent, then a comma-delimited list of all of the pin voltages will be returned. If current mode is sent, then only pins setup as current output or LLA inputs will return numeric current values. Other pins will return "*".

Format: P,[V,I]\n
- P: Read All Instruction Type
- [V,I]: V=voltage mode I=current mode
example: Read the voltage present at each of the 25 grid nodes.
- host: "p,v\n"
- ueac: "[voltage pin 1,1],[voltage pin 1,2],...[voltage pin 5,5],OK\n"

Read Probe

Command allowing the voltage or current to be read from a particular probe. The probe is specified by it's row,column grid location. A numeric voltage will be returned from the specified grid point. When in current mode, a numeric value will only be returned if the pin is setup as a current output or LLA input/output. Voltage is returned in volts and current is returned in uA.

Format: R,[V,I],X_LOC,Y_LOC,[Value]\n
- R: Read Probe Instruction Type
- [V,I]: V=voltage I=current
- X_LOC Position of the pin left to right. Ranges from 1-5.
- Y_LOC Position of the pin top to bottom. Ranges from 1-5.
- [Value] Dummy output current ranging from -200uA (sink) to 200uA (source). Used to maintain parser commonality with the Write Probe commands. The value needs to be in the range -200<=value<=200.
example: Read the current flowing at pin 2,2. Assumes that pin 2,2 is setup as a current output or LLA input/output.
- host: "r,i,2,2,100\n"
- ueac: "[current (uA) pin 2,2],OK\n"

Write Probe

Command that allows a pin location to be written to a desired current value. The current value can range from -200 to 200 uA. Negative current values indicate a current sink. Positive values indicate a current source.

Format: W,I,X_LOC,Y_LOC,[Value]\n
- W: Write Probe Instruction Type
- I: Current mode instruction
- X_LOC Position of the pin left to right. Ranges from 1-5.
- Y_LOC Position of the pin top to bottom. Ranges from 1-5.
- [Value] Output current ranging from -200uA (sink) to 200uA (source).
example: Cause pin 1,1 to source 150uA.
- host: "w,i,1,1,150\n"
- ueac: "OK\n"

LLA Instantiation

Command that allows LLA relationships to be added or removed.

Format:L,[A,D,E,R],XIN_LOC,YIN_LOC,XOUT_LOC,YOUT_LOC,NUM_DESCR,FUNC,PERIOD\n
- L: LLA Instantiation Instruction Type
- [A,D,E,R]: Add,Disable,Enable,Report
- XIN_LOC: LLA input Pin X location. Position of the pin left to right. Ranges from 1-5.
- YIN_LOC: LLA input Pin Y location. Position of the pin left to right. Ranges from 1-5.
- XOUT_LOC: LLA output Pin X location. Position of the pin left to right. Ranges from 0-5. 0 indicates that the output is virtual and is not physically connected to the sheet. Both the XOUT_LOC and YOUT_LOC need to be 0 to be accepted as a virtual output.
- YOUT_LOC: LLA output Pin Y location. Position of the pin left to right. Ranges from 0-5. 0 indicates that the output is virtual and is not physically connected to the sheet. Both the XOUT_LOC and YOUT_LOC need to be 0 to be accepted as a virtual output.
- NUM_DESCR: User defined numeric descriptor to use to refer to the specific lla. Ranges from 1-10.
- FUNC: LLA Function number. This number can range from 1-50. The functions are lookup tables that have an input range of 0-200uA and an output range of -200uA-200uA. The first 27 functions are the 27 basic LLA functions described by Jonathan Mills.
- PERIOD: Determines the rate at which the LLA should be evaluated. This number specifies the integer multiple of the base 10mS LLA evaluation interval. The period can range from 1-255. If the specified period is greater than 1, then the input pins is sampled at the base rate and averaged at the specified interval to use to look-up the output value.

Reset Board

Causes the MSP430 to go through a full system reset. This does not effect the FTDI USB interface.

Format: RST\n
example: Resets the board causing all of the current sources to go back to a value of 0uA.
- host: "rst\n"
- ueac: "OK\n" then goes through power-on-self-test to arrive back at the prompt.

LED Screen

These commands allow the LED screen to be enabled and disabled. The LED screen is enabled by default.

Enable Format: LON\n
Disable Format: LOF\n
example: Turns off the LED screen. This might be important for noise reduction.
- host: "lof\n"
- ueac: "OK\n" The screen is disabled immediately.

Probe Calibration

Command that allows the probes on the board to be calibrated at manufacturing test. This command requires the foam substrate to be removed from the board to complete successfully. Do not run this command unless you are certain that you know what you are doing. If you run it by accident, just index through the tests using enter. Indicate "n" when you are asked to commit the values to external flash.

Format: CAL\n
example: Calibrate the current supplies and measurement points. Each of the 25 probes is calibrated at 200uA (output), 0uA (output), 200uA (input), 3.3V (input).
- host: "cal\n"
- ueac:
  Current Output Calibration
  Attach the DVM in current mode to the pin with the active LED
  Use the up arrow and down arrow keys to adjust the current
  -----------------------------------------------------------------
  0@200uA><\blockquote>