3.2.3 A/D Converter Inputs (RCM4000 only)
The following sample programs are found in the SAMPLES\RCM4000\ADC folder.
•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.
•THERMISTOR.C—Demonstrates how to use analog input LN7 to calculate temperature for display to the STDIO window. This sample program assumes that the thermistor is the one included in the Development Kit whose values for beta, series resistance, and resistance at standard temperature are given in the part specification.
Install the thermistor at location JP25 on the Prototyping Board before running this sample program.
3.2.4 Real-Time Clock
If you plan to use the real-time clock functionality in your application, you will need to set the real-time clock. Set the real-time clock using the SETRTCKB.C sample program from the Dynamic C SAMPLES\RTCLOCK folder, using the onscreen prompts. The RTC_TEST.C sample program in the Dynamic C SAMPLES\RTCLOCK folder provides additional examples of how to read and set the real-time clock.
