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Demo of Embedded Artists LPCXpresso baseboard SD card reader and audio facilities. Updated to put wav file player in a separate library and use the high capacity SD card library provided by Klaus Bu.
Diff: main.cpp
- Revision:
- 0:1f4b7aa80ab3
- Child:
- 1:22c43c468a2f
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Sat Jul 03 10:07:07 2010 +0000 @@ -0,0 +1,245 @@ +/* + Demo of Embedded Artists LPCXpresso baseboard SD card + reader and audio facilities. + + WAVEplayer by Vlad Cazan/Stephan Rochon modified by Tom Coxon + to run correctly on the Embedded Artists LPCXpresso baseboard. + + Also modified to play 8 bit sample size in addition to + original 16 bit. + + Place suitable wav files with 8 or 16 bit sample sizes on the + SD card and ensure the file names are 8.3 format. Then change + the main method below to the relevant file paths. + + Please set all jumpers on board to the default case except for + the following: + + Audio setup: + + 1. Insert a jumper in J31 to connect signal PIO1_2 to the low + pass filer as described in section 4.7.2. of base board users + guide. + + 2. Insert three jumpers in J33 to connect PIO3_0, PIO3_1 and + PIO3_2 to control the amplifier as described in section 4.8 + of base board users guide. + + 3. Insert a jumper in J32 and remove any from J34 to use the + internal speaker as described in section 4.8 + of base board users guide. + + SD Card setup: + + 4. Insert all five jumpers in J39 as described in section 4.3.3 + of base board users guide. + + 5. Remove jumper marked "A" in J55 In order to connect PIO1_11 + to CS signal of J40 (the SPI-SSEL signal) as described in section 4.3.3 + of base board users guide. +*/ + +#include "mbed.h" +#include "SDFileSystem.h" + +AnalogOut DACout(p18); +DigitalOut led1(LED1); +DigitalOut led2(LED2); +DigitalOut led3(LED3); +DigitalOut led4(LED4); +Ticker tick; +SDFileSystem sd(p5, p6, p7, p24, "sd"); + +#define SAMPLE_FREQ 40000 +#define BUF_SIZE (SAMPLE_FREQ/10) +#define SLICE_BUF_SIZE 1 + +void dac_out(void); +void play_wave(char *); +void cleanup(char *); +void fill_adc_buf(short *, unsigned); +void swapword(unsigned *); + +// a FIFO for the DAC +short DAC_fifo[256]; +short DAC_wptr; +short DAC_rptr; +short DAC_on; + +typedef struct uFMT_STRUCT { + short comp_code; + short num_channels; + unsigned sample_rate; + unsigned avg_Bps; + short block_align; + short sig_bps; +} FMT_STRUCT; + + +int main() { + led1=0; + wait(.5); + led1=1; + wait(.5); + led1=0; + printf("\r\n--------------- Starting -----------------\r\n"); + + play_wave("/sd/startup.wav"); // 8 bit sample size + + play_wave("/sd/baddonut.wav"); // 16 bit sample size + + play_wave("/sd/dduck.wav"); // 8 bit sample size + + play_wave("/sd/bbunny.wav"); // 8 bit sample size + + play_wave("/sd/clint16.wav"); // 16 bit sample size + + printf("<<<<<<<<<<<<<<<< All done >>>>>>>>>>>>>>>>\r\n"); + led1=1; + wait(.5); + led1=0; + wait(.5); + led1=1; +} + +void play_wave(char *wavname) { + unsigned chunk_id,chunk_size,channel; + unsigned data,samp_int,i; + short dac_data; + char *slice_buf; + short *data_sptr; + FMT_STRUCT wav_format; + FILE *wavfile; + long slice,num_slices; + DAC_wptr=0; + DAC_rptr=0; + for (i=0;i<256;i+=2) { + DAC_fifo[i]=0; + DAC_fifo[i+1]=3000; + } + DAC_wptr=4; + DAC_on=0; + + led1=led2=led3=led4=0; + + printf("Playing wave file '%s'\r\n",wavname); + + wavfile=fopen(wavname,"rb"); + if (!wavfile) { + printf("Unable to open wav file '%s'\r\n",wavname); + exit(1); + } + + fread(&chunk_id,4,1,wavfile); + fread(&chunk_size,4,1,wavfile); + while (!feof(wavfile)) { + printf("Read chunk ID 0x%x, size 0x%x\r\n",chunk_id,chunk_size); + switch (chunk_id) { + case 0x46464952: + fread(&data,4,1,wavfile); + printf("RIFF chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" RIFF type 0x%x\r\n",data); + break; + case 0x20746d66: + fread(&wav_format,sizeof(wav_format),1,wavfile); + printf("FORMAT chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" compression code %d\r\n",wav_format.comp_code); + printf(" %d channels\r\n",wav_format.num_channels); + printf(" %d samples/sec\r\n",wav_format.sample_rate); + printf(" %d bytes/sec\r\n",wav_format.avg_Bps); + printf(" block align %d\r\n",wav_format.block_align); + printf(" %d bits per sample\r\n",wav_format.sig_bps); + if (chunk_size > sizeof(wav_format)) + fseek(wavfile,chunk_size-sizeof(wav_format),SEEK_CUR); +// create a slice buffer large enough to hold multiple slices + slice_buf=(char *)malloc(wav_format.block_align*SLICE_BUF_SIZE); + if (!slice_buf) { + printf("Unable to malloc slice buffer"); + exit(1); + } + break; + case 0x61746164: + slice_buf=(char *)malloc(wav_format.block_align*SLICE_BUF_SIZE); + if (!slice_buf) { + printf("Unable to malloc slice buffer"); + exit(1); + } + num_slices=chunk_size/wav_format.block_align; + printf("DATA chunk\r\n"); + printf(" chunk size %d (0x%x)\r\n",chunk_size,chunk_size); + printf(" %d slices\r\n",num_slices); + printf(" Ideal sample interval=%d\r\n",(unsigned)(1000000.0/wav_format.sample_rate)); + samp_int=1000000/(wav_format.sample_rate); + printf(" programmed interrupt tick interval=%d\r\n",samp_int); + +// starting up ticker to write samples out -- no printfs until tick.detach is called + tick.attach_us(&dac_out, samp_int); + DAC_on=1; + led2=1; + for (slice=0;slice<num_slices;slice+=SLICE_BUF_SIZE) { + fread(slice_buf,wav_format.block_align*SLICE_BUF_SIZE,1,wavfile); + if (feof(wavfile)) { + printf("Oops -- not enough slices in the wave file\r\n"); + exit(1); + } + data_sptr=(short *)slice_buf; + for (i=0;i<SLICE_BUF_SIZE;i++) { + dac_data=0; + +// for a stereo wave file average the two channels. + for (channel=0;channel<wav_format.num_channels;channel++) { + switch (wav_format.sig_bps) { + case 16: + dac_data+=( ((int)(*data_sptr++)) +32768 ); + break; + case 8: + dac_data+=( ((int)(*data_sptr++)) +32768 <<8); + break; + } + } + DAC_fifo[DAC_wptr]=dac_data; + DAC_wptr=(DAC_wptr+1) & 0xff; + while (DAC_wptr==DAC_rptr) { + led1=1; + wait_us(10); + } + led1=0; + } + } + DAC_on=0; + led2=0; + tick.detach(); + printf("Ticker detached\r\n"); + led3=1; + free(slice_buf); + break; + case 0x5453494c: + printf("INFO chunk, size %d\r\n",chunk_size); + fseek(wavfile,chunk_size,SEEK_CUR); + break; + default: + printf("unknown chunk type 0x%x, size %d\r\n",chunk_id,chunk_size); + data=fseek(wavfile,chunk_size,SEEK_CUR); + break; + } + fread(&chunk_id,4,1,wavfile); + fread(&chunk_size,4,1,wavfile); + } + printf("++++++++++++ Done with wave file ++++++++++\r\n"); + fclose(wavfile); + led1=0; +} + + +void dac_out() { + if (DAC_on) { + led4=1; + DACout.write_u16(DAC_fifo[DAC_rptr]); + DAC_rptr=(DAC_rptr+1) & 0xff; + led4=0; + } +} + +