This section refers to the following sample application(s):
03-radioTest
This application is new to OCSDK 1.2.0
This sample
The 02-radioTest Sample Application
The application provides five CLI functions (available by typing help) for setting the state of pin DP2 (GPIO 21):
initPer- sets the initial period, in ns. By default, it is set toDN_PWM_8P9MS(8.9 ms). Cannot be called when the PWM is open.initDuty- sets the initial duty cycle, expressed as the asserted portion of the period in ns.openPWM- opens theDN_PWM_DEV_IDdevice (PWM0, LTC5800 pin 49). The device must be opened before enabling/disabling the PWM.enablePWM- enables the PWM signal output on PWM0.disablePWM- disables the PWM signal output on PWM0setDuty- sets the current duty cycle, expressed as the asserted portion of the period in ns.closePWM- closes the pwm device and disable output. The PWM must be closed before changing the period.
Each CLI command prints a confirmation:
PWM app, ver 1.2.0.1 SmartMeshIP stack, ver 1.4.1.6 initPer 8888889 Config Period: 8888889 >initDuty 2222222 Initial duty cycle: 2222222 >openPWM Open PWM with period=8888889 and initial duty cycle=2222222 >enablePWM enabledPWM >setDuty 4444444 New duty cycle: 4444444 >disablePWM Disabled PWM >closePWM ClosedPWM
Implementation Details
The 02-pwm sample application uses the Helper Modules to initialize the CLI Module and for interaction with the local interface. It passes JOIN_NO in the fJoin flag when initializing the local module in the loc_task_init() to prevent the local module from attempting to join. It does not start any application tasks - it relies solely on CLI commands to drive the PWM to demonstrate its features.
The application defines a default period, DEFAULT_PERIOD, in ns, and a default duty cycle that is 50% of the default period (DEFAULT_PERIOD/2).
While the period can be set to any value, there is an enumerated list of guaranteed glitch-free periods. When using other periods, enabling the pwm may produce a single cycle of the pin being asserted for an arbitrary portion of the period. For this reason, it is recommended to use one of the periods defined in dnm_pwm.h.