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@robodude666 robodude666/main.cpp
Created Jun 10, 2011

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Primitive ADC + DMA testing and benchmarking on the Maple r5
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <math.h>
#include "wirish.h"
#include "dma.h"
// Force init to be called *first*, i.e. before static object allocation.
// Otherwise, statically allocated objects that need libmaple may fail.
__attribute__((constructor)) void premain() { init(); }
#define DMA_DEV DMA1
#define DMA_CHANNEL DMA_CH1
#define BUF_TO_PRINT 8
#define BUF_SIZE 512
uint16_t adcDMABuffer[BUF_SIZE];
uint16_t printPeriod = 100;
uint32_t lastPrinted = 0;
uint32_t currentMillis = 0;
uint32_t startedMillis = 0;
int main()
{
for(int i = 0; i < BUF_SIZE; i++) adcDMABuffer[i] = 0;
// Setup DMA
dma_init(DMA_DEV);
dma_setup_transfer(DMA_DEV, DMA_CHANNEL,
&ADC1->regs->DR, DMA_SIZE_16BITS,
adcDMABuffer, DMA_SIZE_16BITS,
(DMA_MINC_MODE | DMA_CIRC_MODE | DMA_TRNS_CMPLT)
);
dma_set_num_transfers(DMA_DEV, DMA_CHANNEL, BUF_SIZE);
int isDMAEnabled = 0;
while(isDMAEnabled == 0)
{
currentMillis = millis();
// Wait 6 seconds before starting DMA.
if(currentMillis >= 6000)
{
startedMillis = currentMillis;
isDMAEnabled = 1;
// Configure ADC and Enable DMA
adc_init(ADC1);
adc_set_sample_rate(ADC1, ADC_SMPR_7_5); // Sample rate?
adc_set_exttrig(ADC1, 1); // Does something useful, I think?
adc_set_reg_seqlen(ADC1, 1); // 1 Channel per sequence?
ADC1->regs->SQR3 = 1; // Channel 1
// DMA, Enable, SW Start, Cont. Mode, SWSTART Ext. Sel
ADC1->regs->CR2 |= (ADC_CR2_DMA | ADC_CR2_ADON | ADC_CR2_SWSTART | ADC_CR2_CONT | ADC_CR2_EXTSEL);
dma_enable(DMA1, DMA_CHANNEL);
SerialUSB.println("DMA Channel Enabled!");
}
else
{
if(currentMillis > (lastPrinted + printPeriod))
{
lastPrinted = currentMillis;
SerialUSB.print("[");
SerialUSB.print(currentMillis);
SerialUSB.println("] Warming Up...");
}
}
}
uint8_t previousISRBits = 0;
uint16_t isrCounts = 0;
while(1)
{
currentMillis = millis();
uint8_t isr_bits = dma_get_isr_bits(DMA_DEV, DMA_CHANNEL);
if(currentMillis > (lastPrinted + printPeriod))
{
lastPrinted = currentMillis;
dma_channel_reg_map *ch_regs = dma_channel_regs(DMA_DEV, DMA_CHANNEL);
SerialUSB.print("[");
SerialUSB.print(currentMillis - startedMillis);
SerialUSB.print("] ISR bits: 0x");
SerialUSB.print((int32)isr_bits, HEX);
SerialUSB.print(" CCR: 0x");
SerialUSB.print((int64)ch_regs->CCR, HEX);
SerialUSB.print(" CNDTR: ");
SerialUSB.print((int64)ch_regs->CNDTR);
SerialUSB.print(" ISR Counts: ");
SerialUSB.print(isrCounts);
SerialUSB.print(" Buffer contents: ");
for (int i = 0; i < (BUF_SIZE <= BUF_TO_PRINT ? BUF_SIZE : BUF_TO_PRINT); i++)
{
SerialUSB.print('\'');
SerialUSB.print(adcDMABuffer[i]);
SerialUSB.print('\'');
if (i < BUF_SIZE - 1) SerialUSB.print(", ");
}
if(BUF_SIZE > BUF_TO_PRINT) SerialUSB.print("...");
SerialUSB.println();
}
if(isr_bits == 0x7)
{
//SerialUSB.println("** Clearing ISR bits.");
dma_clear_isr_bits(DMA_DEV, DMA_CHANNEL);
}
if(previousISRBits != isr_bits && isr_bits == 0x7)
{
isrCounts++;
}
previousISRBits = isr_bits;
}
return 0;
}
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