modification of Andrew Kirkhams MODDMA code to send packets over Ethernet and using multiple ADC channels
Dependencies: EthernetInterface MODDMA mbed-rtos mbed
Diff: main.cpp
- Revision:
- 0:68a1564919d0
diff -r 000000000000 -r 68a1564919d0 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Tue Aug 05 22:06:11 2014 +0000 @@ -0,0 +1,146 @@ +/*This code is based off of Andy Kirkham's +*work making MODDMA. +*http://mbed.org/users/AjK/code/MODDMA/ +*/ +#include "mbed.h" +#include "MODDMA.h" +#include "string.h" +#include "EthernetInterface.h" + +#define NUM_SAMPLES 1024 +#define BYTES_PER_SAMPLE sizeof(uint16_t) / sizeof(char) +#define NUM_CHANNELS 4 +#define SAMPLE_BUFF_LEN NUM_SAMPLES*NUM_CHANNELS +#define SAMPLE_BUFF_BYTES SAMPLE_BUFF_LEN * BYTES_PER_SAMPLE + +DigitalOut led1(LED1); +DigitalOut led2(LED2); + +MODDMA dma; +const int BROADCAST_PORT = 58083; + +// ISR set's this when transfer complete. +bool dmaTransferComplete = false; + +// Function prototypes for IRQ callbacks. +// See definitions following main() below. +void TC0_callback(void); +void ERR0_callback(void); + +int main() { + //Set up the ethernet to broadcast + EthernetInterface eth; + eth.init(); //Use DHCP + eth.connect(); + + UDPSocket sock; + sock.init(); + sock.set_broadcasting(); + + Endpoint broadcast; + broadcast.set_address("255.255.255.255", BROADCAST_PORT); + + // Create a buffer to hold the ADC samples and clear it. + // Note, we are going to sample two ADC inputs so they + // end up in this buffer "interleaved". So you will want + // a buffer twice this size to a real life given sample + // frequency. See the printf() output for details. + uint16_t adcInputBuffer[SAMPLE_BUFF_LEN]; + memset(adcInputBuffer, 0, SAMPLE_BUFF_BYTES); + + // We use the ADC irq to trigger DMA and the manual says + // that in this case the NVIC for ADC must be disabled. + NVIC_DisableIRQ(ADC_IRQn); + + // Power up the ADC and set PCLK + LPC_SC->PCONP |= (1UL << 12); + LPC_SC->PCLKSEL0 &= ~(3UL << 24); // PCLK = CCLK/4 96M/4 = 24MHz + + // Enable the ADC, 12MHz, ADC0.0 & .1 + //LPC_ADC->ADCR = (1UL << 21) | (1UL << 8) | (3UL << 0); + LPC_ADC->ADCR = (1UL << 21) | (1UL << 8) | (15UL << 0); + + // Set the pin functions to ADC + LPC_PINCON->PINSEL1 &= ~(3UL << 14); /* P0.23, Mbed p15. */ + LPC_PINCON->PINSEL1 |= (1UL << 14); + LPC_PINCON->PINSEL1 &= ~(3UL << 16); /* P0.24, Mbed p16. */ + LPC_PINCON->PINSEL1 |= (1UL << 16); + LPC_PINCON->PINSEL1 &= ~(3UL << 18); /* P0.25, Mbed p17. */ + LPC_PINCON->PINSEL1 |= (1UL << 18); + LPC_PINCON->PINSEL1 &= ~(3UL << 20); /* P0.26, Mbed p18. */ + LPC_PINCON->PINSEL1 |= (1UL << 20); + + // Prepare an ADC configuration. + MODDMA_Config *conf = new MODDMA_Config; + conf + ->channelNum ( MODDMA::Channel_0 ) + ->srcMemAddr ( 0 ) + ->dstMemAddr ( (uint32_t)adcInputBuffer ) //NOT a dereference, just storing a 32bit pointer value as int + ->transferSize ( SAMPLE_BUFF_LEN ) + ->transferType ( MODDMA::p2m ) + ->transferWidth ( MODDMA::word ) + ->srcConn ( MODDMA::ADC ) + ->dstConn ( 0 ) + ->dmaLLI ( 0 ) + ->attach_tc ( &TC0_callback ) + ->attach_err ( &ERR0_callback ) + ; // end conf. + + // Prepare configuration. + dma.Setup( conf ); + + // Enable configuration. + dma.Enable( conf ); + + // Enable ADC irq flag (to DMA). + // Note, don't set the individual flags, + // just set the global flag. + LPC_ADC->ADINTEN = 0x100; + + // Enable burst mode on inputs 0 and 1. + LPC_ADC->ADCR |= (1UL << 16); + + + while (1) { + // When transfer complete do this block. + if (dmaTransferComplete) { + delete conf; // No memory leaks, delete the configuration. + dmaTransferComplete = false; + } + //sock.sendTo(broadcast, out_buffer, sizeof(out_buffer)); + sock.sendTo(broadcast, (char*)adcInputBuffer, SAMPLE_BUFF_BYTES); + wait(0.25); + } +} + +// Configuration callback on TC +void TC0_callback(void) { + + MODDMA_Config *config = dma.getConfig(); + + // Disbale burst mode and switch off the IRQ flag. + LPC_ADC->ADCR &= ~(1UL << 16); + LPC_ADC->ADINTEN = 0; + + // Finish the DMA cycle by shutting down the channel. + dma.haltAndWaitChannelComplete( (MODDMA::CHANNELS)config->channelNum()); + dma.Disable( (MODDMA::CHANNELS)config->channelNum() ); + + // Tell main() while(1) loop to print the results. + dmaTransferComplete = true; + + // Switch on LED2 to show transfer complete. + led2 = 1; + + // Clear DMA IRQ flags. + if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq(); + if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq(); +} + +// Configuration callback on Error +void ERR0_callback(void) { + // Switch off burst conversions. + LPC_ADC->ADCR |= ~(1UL << 16); + LPC_ADC->ADINTEN = 0; + error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem"); +}