Hello Daniel,
Kinetis K70 is not supported in KSDK 1.2.0 so you need to create a new project that uses Processor Expert Support.
Basically, you need to configure 2 ADC modules (ADC0 and ADC1, each one using 2 channels) to be triggered by Programmable Delay Module (PDB). PDB module will allow you to trigger every ADC channel with specific time intervals.
- ADC:
We configure every ADC module to use Single conversion mode, 16-bit format and HW Trigger.
Then, we configure pins used for Channel 0 and Channel 1. After this, we configure trigger sources for Trigger A and B (Select PDB0_CH0_TriggerA and PDB0_CH0_TriggerB respectively)
We will manage results using interrupt mode, so ensure to enable interrupt for every ADC module in both conversion complete (A and B):
Finally, we configure ADC part triggered by trigger A and B as follows:
ADC configuration the same for both modules (obviously, selecting corresponding channels to use ADCx_DPn and ADCx_DMn). Now it is time to configure PDB component.
- PDB:
PDB is a timer that generates trigger pulses to peripherals such as ADC, DAC and CMP. In this case, we will use 4 triggers.
In this configuration, we select the PDB source clock (Derived from Bus clock) This clock is calculated as (Bus Clock / (Divider * Prescaler)).
Once frequency is calculated, we set the value in which the timer will be reset, in this case, as source clock is 15MHz, we select modulus value to be 15000 to have 1 ms period.
(1 / 15MHz = 66nS; 15000 * 66nS = 1ms)
We select the continuous mode (once the input trigger is received, timer will count until it reaches modulus value, then, it is reset and start counting again.)
In next tab (Channels) we configure Channel 0 trigger and Channel 1 trigger to generate triggers at 250 us, 500us, 750us and 1ms:
We have configured both peripherals in order to be read one ADC channel every 250 us (so every 1 ms we will read these 4 channles).
Now, generate PE code.
In main.c file, we add header files for ADC and PDB:
#include "PDB_PDD.h"
#include "ADC_PDD.h"
And add Interrupt Service Routines for ADC0 and ADC1:
void ADC0_ISR () {
if (ADC_PDD_GetConversionCompleteFlag(ADC0_DEVICE,0)) {
ADC0_A_conv = ADC_PDD_GetResultValueRaw(ADC0_DEVICE,0);
}
if (ADC_PDD_GetConversionCompleteFlag(ADC0_DEVICE,1)) {
ADC0_B_conv = ADC_PDD_ReadDataResultReg(ADC0_DEVICE,1);
}
}
void ADC1_ISR () {
if (ADC_PDD_GetConversionCompleteFlag(ADC1_DEVICE,0)) {
ADC1_A_conv = ADC_PDD_GetResultValueRaw(ADC1_DEVICE,0);
}
if (ADC_PDD_GetConversionCompleteFlag(ADC1_DEVICE,1)) {
ADC1_B_conv = ADC_PDD_ReadDataResultReg(ADC1_DEVICE,1);
}
}
ADC0_A_conv, ADC0_B_conv, ADC1_A_conv and ADC1_B_conv will save the converted value for each channel.
Then, we only need to trigger PDB channel in order to start conversions on ADC. Like we select PDB software trigger, we call next function:
/* Write your local variable definition here */
/*** Processor Expert internal initialization. DON'T REMOVE THIS CODE!!! ***/
PE_low_level_init();
/*** End of Processor Expert internal initialization. ***/
PDB_PDD_SoftwareTrigger(PDB0_DEVICE);
for (;;) {
}
I attach this project in which I add DAC support to convert this digital value into an analog value again, and verify that every channel (with constant analog value) is sample every 250us:
As you can see on previous image, 4 channels are sample every 1 ms. If you desired to change this value, it is necessary to modify PDB's period and Channels delays.
I hope this can help you.
Best Regards,
Isaac
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