Jeroen Lodder
Generate sine waves with 2 mbeds synchronised. Configurable amplitude and phase. Built for 50 Hz mains simulations.
Description
Small program based on the MODDMA buffered sine wave example.
This programs reads pin 22 to operate in Master (low) or Slave mode. Then configures pin 21 as output (master) or input (slave), in master mode led2 is on. Use a resistor (100 ohm) between the pin21's of master to slave.
The program then calculates a buffer of sine waves for the DMA with parameters given. And starts the DMA and DAC to generate the sine.
On the callbacks of the dma complete (there are 2) slave waits for a sync and master gives a sync, p21. Master waits a few extra clocks to make sure slave is ready.
Commands can be given over Serial port to modify the parameters on the run. Frequency can be changed for master and slave, but it is better to keep the same. Use "f xx.xx". Phase can be changed for master and slave Amplitude can be changed for master and slave.
Hookup
- Wire p22 high or low.
- Serial sr(p9,p10) from master to slave.
- Wire trigger p21 to p21.
- Output p18 (analogout)
Information
Do not forget a small RC filter on the DAC output.
Master Commands
<master/slave/frequency> <frequency/phase/amplitude> <space> <number> <line feed>
Example commands for serial:
- master frequency 50.1 hz
- mf 50.1\n
- frequency 50.1 Hz
- f 50.1\n
- master phase 3.1415 (or 1.0)
- mp 1\n
- slave phase 1.5 pi
- sp 1.5\n
Or use this GUI
Download, or Download C# Code (Visual Studio 2010)
Diff: main.cpp
- Revision:
- 2:edd6401d9aa0
- Parent:
- 1:b97d61d415ff
- Child:
- 3:67b9a01ad7b0
--- a/main.cpp Thu May 30 21:24:35 2013 +0000
+++ b/main.cpp Fri May 31 14:45:27 2013 +0000
@@ -6,8 +6,15 @@
#include "mbed.h"
#include "MODDMA.h"
#include <cmath>
+#include "watchdog.h"
+#include "xifo.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
Serial pc(USBTX, USBRX);
+Serial sr(p9, p10);
+Watchdog wdt;
const double PI = 3.141592653589793238462;
const float PI_F = 3.14159265358979f;
@@ -23,37 +30,42 @@
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);
-DigitalIn modesel(p22);
-DigitalInOut trigger(p21);
-
-DigitalOut timetest(p23);
+DigitalIn modesel(p22); // mode selector
+DigitalInOut trigger(p21); // sync trigger output
-int buffer[2][BUFFER_SIZE];
-
-typedef enum {MASTER, SLAVE} modesel_t;
-modesel_t mode;
+uint32_t buffer[3][BUFFER_SIZE];
AnalogOut signal(p18);
MODDMA dma;
-MODDMA_Config *conf0, *conf1;
+MODDMA_Config *conf0, *conf1, *conf2, *conf3;
+// Config phase (2*pi is one period)
+double phase_master = PI * 1;
+double phase_slave = PI * 1;
+// Config amplitude, x * 3.3 Volt
+double amplitude_master = 1;
+double amplitude_slave = 1;
+// Config frequency, (if using synchronisation these must be identical)
+double freq_master = 50;
+double freq_slave = freq_master;
+// copy calc buffer[2] to ch0/1
+volatile uint32_t toch0 = 0;
+volatile uint32_t toch1 = 0;
+// Mode typedef
+typedef enum {MASTER, SLAVE} modesel_t;
+modesel_t mode;
+// Ringbuffer for cmd
+xifo_t com;
+xifo_pool_t compool[128];
+
+/* Dma callbacks */
void TC0_callback(void);
void ERR0_callback(void);
void TC1_callback(void);
void ERR1_callback(void);
-// Config phase (2*pi is one period)
-double phase_master = PI * 0;
-double phase_slave = PI * 0;
-// Config amplitude, x * 3.3 Volt
-double amplitude_master = 1;
-double amplitude_slave = 0.5;
-// Config frequency, (if using synchronisation these must be identical)
-double freq_master = 50;
-double freq_slave = freq_master;
-
// Sync function
void wait_for_sync(){
switch(mode){
@@ -78,25 +90,37 @@
// Create a sinewave buffer for testing.
switch(mode){
case MASTER:
- for (int i = 0; i <= 360; i++) buffer[0][i] = amplitude_master * (512 * sin((3.14159/180.0 * i) + phase_master)) + 512;
+ for (int i = 0; i <= 359; i++)
+ {
+ double rads = (PI/180.0 * i);
+ buffer[0][i] = amplitude_master * (512*( sin( rads + phase_master ) ))+512;
+ }
break;
case SLAVE:
- for (int i = 0; i <= 360; i++) buffer[0][i] = amplitude_slave * (512 * sin((3.14159/180.0 * i) + phase_slave)) + 512;
+ for (int i = 0; i <= 359; i++)
+ {
+ double rads = (PI/180.0 * i);
+ buffer[0][i] = amplitude_slave * (512 * sin(rads + phase_slave)) + 512;
+ }
break;
}
// Adjust the sinewave buffer for use with DAC hardware.
for (int i = 0; i < 360; i++) {
- buffer[0][i] = DAC_POWER_MODE | ((buffer[0][i] << 6) & 0xFFC0);
+ if( buffer[0][i] > 1023 ) buffer[0][i] = 1023;
+ buffer[0][i] = DAC_POWER_MODE | ((buffer[0][i] << 6) & 0xFFC0);
buffer[1][i] = buffer[0][i]; // Just create a copy of buffer0 to continue sinewave.
}
}
+void copycallback(){
+ if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
+}
+
// Main
int main() {
volatile int life_counter = 0;
pc.baud(115200);
- timetest = 0;
if(modesel == 1){
pc.printf("slave\r\n");
@@ -108,6 +132,11 @@
trigger.output();
led2 = 1;
mode = MASTER;
+ // Print command set
+ pc.printf("Command descriptions: <[master][slave]><[frequency][amplitude][phase]> <number>\r\n");
+ pc.printf("Commands: <[m][s]><[f][a][p]> <n>\r\n");
+ pc.printf("Min F = 1.02 Hz\r\n");
+ pc.printf("Max F limited to synchronisation and DAC speed (200 Hz with sync, max 1000 Hz without)\r\n");
}
calculate_sines();
@@ -125,7 +154,6 @@
->attach_err ( &ERR0_callback )
; // config end
-
// Prepare the GPDMA system for buffer1.
conf1 = new MODDMA_Config;
conf1
@@ -138,8 +166,8 @@
->attach_tc ( &TC1_callback )
->attach_err ( &ERR1_callback )
; // config end
-
-
+
+
// Calculating the transfer frequency:
// By default, the Mbed library sets the PCLK_DAC clock value
// to 24MHz. One complete sinewave cycle in each buffer is 360
@@ -165,12 +193,15 @@
}
unsigned int dacdiv = ddacdiv;
LPC_DAC->DACCNTVAL = dacdiv; // 6500 for 10Hz
+
+ // Watchdogtimer to reset if sync failed
+ wdt.kick(10.0*(1.0/(dacper/ddacdiv)));
// Prepare first configuration.
if (!dma.Prepare( conf0 )) {
error("Doh!");
}
-
+ // Wait period for master (slaves waits for sync)
if(mode == MASTER){
wait(0.1);
}
@@ -180,27 +211,217 @@
// DBLBUF_ENA as we are using DMA double buffering.
LPC_DAC->DACCTRL |= (3UL << 2);
+ // Disable copy calc buffer flags
+ toch0 = 0;
+ toch1 = 0;
+
+ // Create ringbuffer for parsing
+ xifo_init(&com, 128, (uint32_t *)&compool);
+ xifo_clear(&com);
+ uint32_t do_calc=0;
+
while (1) {
- // There's not a lot to do as DMA and interrupts are
- // now handling the buffer transfers. So we'll just
- // flash led1 to show the Mbed is alive and kicking.
- if (life_counter++ > 1000000) {
- led1 = !led1; // Show some sort of life.
- life_counter = 0;
+ // There's not a lot to do as DMA and interrupts are
+ // now handling the buffer transfers. So we'll just
+ // flash led1 to show the Mbed is alive and kicking.
+ if (life_counter++ > 1000000) {
+ led1 = !led1; // Show some sort of life.
+ life_counter = 0;
+ }
+
+ /* Do UART data processing */
+ if(mode==MASTER){
+ while(pc.readable()){
+ xifo_write(&com, pc.getc());
+ }
+ while(sr.readable()){
+ pc.putc(sr.getc());
+ }
+ }else{
+ while(sr.readable()){
+ xifo_write(&com, sr.getc());
+ }
+ }
+
+
+
+ { /* BLOCK with command parsing */
+ uint32_t do_parse=0;
+ // 123456.123456 accurate
+ char number[13] = {0,0,0,0,0,0,0,0,0,0,0,0,0};
+ uint32_t p=0;
+ // Only parse USB master commands on master mode
+ if(mode==MASTER){
+ // MASTER mode
+ if( xifo_read_mr(&com,0) == '\n'){
+ xifo_pop_mr(&com);
+ // We have a line
+ if( xifo_read_lr(&com,0)== 's' ){ // Slave
+ xifo_pop_lr(&com);
+ pc.printf("Slave ");
+ // command for slave, forward over serial sr
+ while(xifo_get_used(&com))
+ sr.putc(xifo_pop_lr(&com));
+ sr.putc('\n');
+ xifo_init(&com, 128, (uint32_t *)&compool);
+ xifo_clear(&com);
+ } else if( xifo_read_lr(&com,0) == 'm' ){ // Master
+ xifo_pop_lr(&com);
+ pc.printf("Master ");
+ // master
+ // Parsing
+ do_parse =1;
+ } else if( xifo_read_lr(&com,0) == 'f' ){ // Frequency on MASTER and SLAVE
+ // Parse data
+ xifo_pop_lr(&com); // space
+ // Get number
+ while( xifo_get_used(&com) && p < sizeof(number))
+ number[p++] = (char)xifo_pop_lr(&com);
+ freq_master = strtod(number,0);
+ int t = dacper / (freq_master);
+ pc.printf("Master Frequency %f, approximate: %f\nSlave ", freq_master, dacper/t);
+ sr.printf("f %f\n", freq_master);
+ do_calc = 1;
+ } else {
+ pc.printf("fout ");
+ while(xifo_get_used(&com))
+ pc.putc(xifo_pop_lr(&com));
+ pc.putc('\n');
+ xifo_init(&com, 128, (uint32_t *)&compool);
+ xifo_clear(&com);
+ }}
+ }else{
+ // SLAVE mode
+ if( xifo_read_mr(&com,0) == '\n'){
+ xifo_pop_mr(&com);
+ do_parse = 1;
+ }
+ }
+ if(do_parse){
+ do_parse=0;
+
+ // Parse data
+ char filter = xifo_pop_lr(&com);
+ xifo_pop_lr(&com) ; // space
+ // Get number
+ while( xifo_get_used(&com) && p < sizeof(number))
+ number[p++] = (char)xifo_pop_lr(&com);
+
+ if(mode==MASTER){
+ // frequency
+ if( filter == 'f' ){
+ freq_master = strtod(number,0);
+ int t = dacper / (freq_master);
+ pc.printf("Frequency %f, approximate: %f\n", freq_master, dacper/t);
+ do_calc = 1;
+ }else{
+ // amplitude
+ if( filter == 'a'){
+ amplitude_master = strtod(number,0);
+ pc.printf("Amplitude %f\n", amplitude_master);
+ do_calc = 1;
+ }else{
+ // phase
+ if( filter == 'p' ){
+ phase_master = strtod(number,0) * PI;
+ pc.printf("Phase %f\n", phase_master);
+ do_calc = 1;
+ } else{
+ pc.printf("fout ");
+ while(xifo_get_used(&com))
+ pc.putc(xifo_pop_lr(&com));
+ pc.putc('\n');
+ xifo_init(&com, 128, (uint32_t *)&compool);
+ xifo_clear(&com);
+ }}}
+ }else{
+ // frequency
+ if( filter == 'f' ){
+ freq_slave = strtod(number,0);
+ int t = dacper / (freq_slave);
+ sr.printf("Frequency %f, approximate: %f\n", freq_slave, dacper/t);
+ do_calc = 1;
+ }else{
+ // amplitude
+ if( filter == 'a'){
+ amplitude_slave = strtod(number,0);
+ sr.printf("Amplitude %f\n", amplitude_slave);
+ do_calc = 1;
+ }else{
+ // phase
+ if( filter == 'p' ){
+ phase_slave = strtod(number,0) * PI;
+ sr.printf("Phase %f\n", phase_slave);
+ do_calc = 1;
+ } else{
+ sr.printf("fout ");
+ while(xifo_get_used(&com))
+ sr.putc(xifo_pop_lr(&com));
+ sr.putc('\n');
+ xifo_init(&com, 128, (uint32_t *)&compool);
+ xifo_clear(&com);
+ }}}
+ }
+ }
+ } /* BLOCK with command parsing */
+
+ // recalculate
+ if(do_calc){
+ do_calc = 0;
+ // only continue if previous update is complete
+ if( !toch0 && !toch1 ){
+ // calc frequency
+ switch(mode){
+ case MASTER:
+ ddacdiv = dacper / (freq_master);
+ //pc.printf("set dacdiv to %f\n",ddacdiv);
+ break;
+ case SLAVE:
+ ddacdiv = dacper / (freq_slave);
+ break;
+ }
+ unsigned int dacdiv = ddacdiv;
+ LPC_DAC->DACCNTVAL = dacdiv; // 6500 for 10Hz
+ wdt.kick(10.0*(1.0/(dacper/ddacdiv)));
+ // calculate_sines sine
+ switch(mode){
+ case MASTER:
+ for (int i = 0; i <= 359; i++)
+ {
+ double rads = (PI/180.0 * i);
+ buffer[2][i] = amplitude_master * (512 * sin( rads + phase_master)) + 512;
+ }
+ break;
+ case SLAVE:
+ for (int i = 0; i <= 359; i++)
+ {
+ double rads = (PI/180.0 * i);
+ buffer[2][i] = amplitude_slave * (512 * sin( rads + phase_slave)) + 512;
+ }
+ break;
+ }
+ // Adjust the sinewave buffer for use with DAC hardware.
+ for (int i = 0; i < 360; i++) {
+ if( buffer[2][i] > 1023 ) buffer[2][i] = 1023;
+ buffer[2][i] = DAC_POWER_MODE | ((buffer[2][i] << 6) & 0xFFC0);
+ }
+ toch0 = 1;
+ toch1 = 1;
+ }
}
- }
+ }
}
// Configuration callback on TC
void TC0_callback(void) {
-
// Just show sending buffer0 complete.
led3 = !led3;
// Implement wait for trigger if slave mode
wait_for_sync();
-
+ wdt.kick();
+
// Get configuration pointer.
MODDMA_Config *config = dma.getConfig();
@@ -212,6 +433,12 @@
// Clear DMA IRQ flags.
if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
+
+ // Copy to channel 0?
+ if ( toch0 ){
+ for (int i = 0; i <= 359; i++) buffer[0][i] = buffer[2][i];
+ toch0=0;
+ }
}
// Configuration callback on Error
@@ -221,24 +448,30 @@
// Configuration callback on TC
void TC1_callback(void) {
-
// Just show sending buffer1 complete.
led4 = !led4;
// Implement wait for trigger if slave mode
wait_for_sync();
+ wdt.kick();
// Get configuration pointer.
MODDMA_Config *config = dma.getConfig();
-
- // Finish the DMA cycle by shutting down the channel.
- dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
-
- // Swap to buffer0
- dma.Prepare( conf0 );
-
- // Clear DMA IRQ flags.
- if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
+
+ // Finish the DMA cycle by shutting down the channel.
+ dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
+
+ // Swap to buffer0
+ dma.Prepare( conf0 );
+
+ // Clear DMA IRQ flags.
+ if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
+
+ // Copy to channel 1?
+ if ( toch1 ){
+ for (int i = 0; i <= 359; i++) buffer[1][i] = buffer[2][i];
+ toch1=0;
+ }
}
// Configuration callback on Error