User’s Manual
23
3.2.3 A/D Converter Inputs (RCM4000 only)
The following sample programs are found in the SAMPLES\RCM4000\ADC folder.
AD_CAL_ALL.C
—Demonstrates how to recalibrate all the single-ended analog input
channels with one gain using two known voltages to generate the calibration constants
for each channel. The constants will be rewritten into the user block data area.
Connect a positive voltage (for example, the power supply positive output) to analog
input channels LN0IN–LN6IN on the Prototyping Board, and connect the ground to
GND. Use a voltmeter to measure the voltage, and follow the instructions in the Dynamic C
STDIO window once you compile and run this sample program. Remember that analog input
LN7 on the Prototyping Board is used with the thermistor and should not be used with this
sample program.
NOTE: The above sample program will overwrite any existing calibration constants.
AD_CAL_CHAN.C
—Demonstrates how to recalibrate one single-ended analog input
channel with one gain using two known voltages to generate the calibration constants
for that channel. The constants will be rewritten into the user block data area.
Connect a positive voltage to an analog input channel on the Prototyping Board, and
connect the ground to GND. Use a voltmeter to measure the voltage, and follow the instruc-
tions in the Dynamic C STDIO window. Remember that analog input LN7 on the Prototyping
Board is used with the thermistor and should not be used with this sample program.
NOTE: The above sample program will overwrite any existing calibration constants.
AD_RDVOLT_ALL.C
—Demonstrates how to read all single-ended A/D input channels
using previously defined calibration constants. Coefficients are read from the simulated
EEPROM in the flash memory to compute equivalent voltages, and cannot be run in
RAM.
Compile and run this sample program once you have connected a positive voltage from
0–20 V DC to an analog input (except LN7) on the Prototyping Board, and ground to
GND. Follow the prompts in the Dynamic C STDIO window. Computed raw data and
equivalent voltages will be displayed.
AD_SAMPLE.C
—Demonstrates how to how to use a low level driver on single-ended
inputs. The program will continuously display the voltage (averaged over 10 samples)
that is present on the A/D converter channels (except LN7). Coefficients are read from
the simulated EEPROM in the flash memory to compute equivalent voltages, so the
sample program cannot be run in RAM.
Compile and run this sample program once you have connected a positive voltage from
0–20 V DC to an analog input (except LN7) on the Prototyping Board, and ground to
GND. Follow the prompts in the Dynamic C STDIO window. Computed raw data and
equivalent voltages will be displayed. If you attach a voltmeter between the analog
input and ground, you will be able to observe that the voltage in the Dynamic C STDIO
window tracks the voltage applied to the analog input as you vary it.