Elisabeth Bradley / wave_player_dma

Edited version of the wave player class that uses the MODDMA library to handle transfers to the DAC.

Dependencies:   MODDMA

Dependents:   WavePlayer_MODDMA wave_player_DMA_mbed

wave_player.cpp@1:11a670498598, 2016-03-16 (annotated)

Committer:
ebradley6
Date:
Wed Mar 16 19:58:55 2016 +0000
Revision:
1:11a670498598
Parent:
0:286582877314 
Updated comments.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ebradley6 0:286582877314 1 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 2 // a sample mbed library to play back wave files using MODDMA
ebradley6 0:286582877314 3 // Based on the wave_player library by Steve Ravet and the
ebradley6 0:286582877314 4 // MODDMA library by Andy Kirkham.
ebradley6 0:286582877314 5 //
ebradley6 0:286582877314 6 // The wave_player library is located here:
ebradley6 0:286582877314 7 // https://developer.mbed.org/users/sravet/code/wave_player/
ebradley6 0:286582877314 8 //
ebradley6 0:286582877314 9 // The MODDMA library is located here:
ebradley6 0:286582877314 10 // https://developer.mbed.org/users/AjK/code/MODDMA/
ebradley6 0:286582877314 11 // A wiki page and example are located here:
ebradley6 0:286582877314 12 // https://developer.mbed.org/cookbook/MODDMA
ebradley6 0:286582877314 13 //
ebradley6 0:286582877314 14 // explanation of wave file format.
ebradley6 0:286582877314 15 // https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
ebradley6 0:286582877314 16
ebradley6 0:286582877314 17 // if VERBOSE is uncommented then the wave player will enter a verbose
ebradley6 0:286582877314 18 // mode that displays all data values as it reads them from the file
ebradley6 0:286582877314 19 // and writes them to the DAC. Very slow and unusable output on the DAC,
ebradley6 0:286582877314 20 // but useful for debugging wave files that don't work.
ebradley6 0:286582877314 21 //#define VERBOSE
ebradley6 0:286582877314 22
ebradley6 0:286582877314 23
ebradley6 0:286582877314 24 #include <mbed.h>
ebradley6 0:286582877314 25 #include <stdio.h>
ebradley6 0:286582877314 26 #include <wave_player.h>
ebradley6 0:286582877314 27
ebradley6 0:286582877314 28 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 29 // constructor -- accepts an mbed pin to use for AnalogOut. Only p18 will work
ebradley6 0:286582877314 30 wave_player::wave_player(AnalogOut *_dac)
ebradley6 0:286582877314 31 {
ebradley6 0:286582877314 32 wave_DAC=_dac;
ebradley6 0:286582877314 33 wave_DAC->write_u16(32768); //DAC is 0-3.3V, so idles at ~1.6V
ebradley6 0:286582877314 34 verbosity=0;
ebradley6 0:286582877314 35 }
ebradley6 0:286582877314 36
ebradley6 0:286582877314 37 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 38 // if verbosity is set then wave player enters a mode where the wave file
ebradley6 0:286582877314 39 // is decoded and displayed to the screen, including sample values put into
ebradley6 0:286582877314 40 // the DAC FIFO, and values read out of the DAC FIFO by the ISR. The DAC output
ebradley6 0:286582877314 41 // itself is so slow as to be unusable, but this might be handy for debugging
ebradley6 0:286582877314 42 // wave files that don't play
ebradley6 0:286582877314 43 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 44 void wave_player::set_verbosity(int v)
ebradley6 0:286582877314 45 {
ebradley6 0:286582877314 46 verbosity=v;
ebradley6 0:286582877314 47 }
ebradley6 0:286582877314 48
ebradley6 0:286582877314 49 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 50 // player function. Takes a pointer to an opened wave file. The file needs
ebradley6 0:286582877314 51 // to be stored in a filesystem with enough bandwidth to feed the wave data.
ebradley6 0:286582877314 52 // LocalFileSystem isn't, but the SDcard is, at least for 22kHz files. The
ebradley6 0:286582877314 53 // SDcard filesystem can be hotrodded by increasing the SPI frequency it uses
ebradley6 0:286582877314 54 // internally.
ebradley6 0:286582877314 55 //-----------------------------------------------------------------------------
ebradley6 0:286582877314 56 void wave_player::play(FILE *wavefile)
ebradley6 0:286582877314 57 {
ebradley6 0:286582877314 58 unsigned chunk_id,chunk_size,channel;
ebradley6 0:286582877314 59 unsigned data,i;
ebradley6 0:286582877314 60 unsigned j,k;
ebradley6 0:286582877314 61 int dac_cntval;
ebradley6 0:286582877314 62 bool buf0_flag;
ebradley6 0:286582877314 63 long long slice_value;
ebradley6 0:286582877314 64 char *slice_buf;
ebradley6 0:286582877314 65 short *data_sptr;
ebradley6 0:286582877314 66 unsigned char *data_bptr;
ebradley6 0:286582877314 67 int *data_wptr;
ebradley6 0:286582877314 68 FMT_STRUCT wav_format;
ebradley6 0:286582877314 69 long num_slices;
ebradley6 0:286582877314 70
ebradley6 0:286582877314 71 for(i=0; i<BUF_SIZE; i++){
ebradley6 0:286582877314 72 DAC_buf0[i]=0;
ebradley6 0:286582877314 73 DAC_buf1[i]=0;
ebradley6 0:286582877314 74 }
ebradley6 0:286582877314 75
ebradley6 0:286582877314 76 DAC_on=0;
ebradley6 0:286582877314 77
ebradley6 0:286582877314 78 int time=0;
ebradley6 0:286582877314 79
ebradley6 0:286582877314 80 fread(&chunk_id,4,1,wavefile);
ebradley6 0:286582877314 81 fread(&chunk_size,4,1,wavefile);
ebradley6 0:286582877314 82
ebradley6 0:286582877314 83 while (!feof(wavefile)) {
ebradley6 0:286582877314 84 if (verbosity)
ebradley6 0:286582877314 85 printf("Read chunk ID 0x%x, size 0x%x\n",chunk_id,chunk_size);
ebradley6 0:286582877314 86 switch (chunk_id) {
ebradley6 0:286582877314 87 case 0x46464952:
ebradley6 0:286582877314 88 fread(&data,4,1,wavefile);
ebradley6 0:286582877314 89 if (verbosity) {
ebradley6 0:286582877314 90 printf("RIFF chunk\n");
ebradley6 0:286582877314 91 printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
ebradley6 0:286582877314 92 printf(" RIFF type 0x%x\n",data);
ebradley6 0:286582877314 93 }
ebradley6 0:286582877314 94 break;
ebradley6 0:286582877314 95 case 0x20746d66:
ebradley6 0:286582877314 96 fread(&wav_format,sizeof(wav_format),1,wavefile);
ebradley6 0:286582877314 97 if (verbosity) {
ebradley6 0:286582877314 98 printf("FORMAT chunk\n");
ebradley6 0:286582877314 99 printf(" chunk size %d (0x%x)\n",chunk_size,chunk_size);
ebradley6 0:286582877314 100 printf(" compression code %d\n",wav_format.comp_code);
ebradley6 0:286582877314 101 printf(" %d channels\n",wav_format.num_channels);
ebradley6 0:286582877314 102 printf(" %d samples/sec\n",wav_format.sample_rate);
ebradley6 0:286582877314 103 printf(" %d bytes/sec\n",wav_format.avg_Bps);
ebradley6 0:286582877314 104 printf(" block align %d\n",wav_format.block_align);
ebradley6 0:286582877314 105 printf(" %d bits per sample\n",wav_format.sig_bps);
ebradley6 0:286582877314 106 }
ebradley6 0:286582877314 107 if (chunk_size > sizeof(wav_format))
ebradley6 0:286582877314 108 fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
ebradley6 0:286582877314 109 break;
ebradley6 0:286582877314 110 case 0x61746164:
ebradley6 1:11a670498598 111 // Data chunk which contains the audio samples to send to the DAC
ebradley6 1:11a670498598 112
ebradley6 0:286582877314 113 // allocate a buffer big enough to hold a slice
ebradley6 0:286582877314 114 slice_buf=(char *)malloc(wav_format.block_align);
ebradley6 0:286582877314 115 if (!slice_buf) {
ebradley6 0:286582877314 116 printf("Unable to malloc slice buffer");
ebradley6 0:286582877314 117 exit(1);
ebradley6 0:286582877314 118 }
ebradley6 0:286582877314 119 num_slices=chunk_size/wav_format.block_align;
ebradley6 0:286582877314 120
ebradley6 0:286582877314 121 // Calculating the transfer frequency:
ebradley6 0:286582877314 122 // By default, the Mbed library sets the PCLK_DAC clock value
ebradley6 0:286582877314 123 // to 24MHz.
ebradley6 0:286582877314 124
ebradley6 0:286582877314 125 dac_cntval=(24000000/wav_format.sample_rate);
ebradley6 0:286582877314 126
ebradley6 0:286582877314 127 if (verbosity) {
ebradley6 0:286582877314 128 printf("DATA chunk\n\r");
ebradley6 0:286582877314 129 printf(" chunk size %d (0x%x)\n\r",chunk_size,chunk_size);
ebradley6 0:286582877314 130 printf(" %d slices\n\r",num_slices);
ebradley6 0:286582877314 131 printf(" sample rate is %d\r\n", wav_format.sample_rate);
ebradley6 0:286582877314 132 printf(" Ideal sample interval=%d\n\r",(unsigned)(1000000.0/wav_format.sample_rate));
ebradley6 0:286582877314 133 printf(" programmed interrupt tick interval=%d\n\r",dac_cntval);
ebradley6 0:286582877314 134 }
ebradley6 0:286582877314 135
ebradley6 0:286582877314 136 // Prepare the GPDMA system for buffer0.
ebradley6 0:286582877314 137 conf0 = new MODDMA_Config;
ebradley6 0:286582877314 138 conf0
ebradley6 0:286582877314 139 ->channelNum ( MODDMA::Channel_0 )
ebradley6 0:286582877314 140 ->srcMemAddr ( (uint32_t) &DAC_buf0 )
ebradley6 0:286582877314 141 ->dstMemAddr ( MODDMA::DAC )
ebradley6 0:286582877314 142 ->transferSize ( BUF_SIZE )
ebradley6 0:286582877314 143 ->transferType ( MODDMA::m2p )
ebradley6 0:286582877314 144 ->dstConn ( MODDMA::DAC )
ebradley6 0:286582877314 145 ->attach_tc ( this,&wave_player::TC0_callback )
ebradley6 0:286582877314 146 ->attach_err ( this,&wave_player::ERR0_callback )
ebradley6 0:286582877314 147 ; // config end
ebradley6 0:286582877314 148
ebradley6 0:286582877314 149 // Prepare the GPDMA system for buffer1.
ebradley6 0:286582877314 150 conf1 = new MODDMA_Config;
ebradley6 0:286582877314 151 conf1
ebradley6 0:286582877314 152 ->channelNum ( MODDMA::Channel_1 )
ebradley6 0:286582877314 153 ->srcMemAddr ( (uint32_t) &DAC_buf1 )
ebradley6 0:286582877314 154 ->dstMemAddr ( MODDMA::DAC )
ebradley6 0:286582877314 155 ->transferSize ( BUF_SIZE )
ebradley6 0:286582877314 156 ->transferType ( MODDMA::m2p )
ebradley6 0:286582877314 157 ->dstConn ( MODDMA::DAC )
ebradley6 0:286582877314 158 ->attach_tc ( this,&wave_player::TC1_callback )
ebradley6 0:286582877314 159 ->attach_err ( this,&wave_player::ERR1_callback )
ebradley6 0:286582877314 160 ; // config end
ebradley6 0:286582877314 161
ebradley6 1:11a670498598 162 // Set the DAC to the audio sample rate
ebradley6 0:286582877314 163 LPC_DAC->DACCNTVAL = dac_cntval;
ebradley6 0:286582877314 164
ebradley6 0:286582877314 165 // Begin (enable DMA and counter). Note, don't enable
ebradley6 0:286582877314 166 // DBLBUF_ENA as we are using DMA double buffering.
ebradley6 0:286582877314 167 LPC_DAC->DACCTRL |= (3UL << 2);
ebradley6 0:286582877314 168
ebradley6 0:286582877314 169 DAC_on=1;
ebradley6 0:286582877314 170
ebradley6 0:286582877314 171 // start reading slices, which contain one sample each for however many channels
ebradley6 0:286582877314 172 // are in the wave file. one channel=mono, two channels=stereo, etc. Since
ebradley6 0:286582877314 173 // mbed only has a single AnalogOut, all of the channels present are averaged
ebradley6 0:286582877314 174 // to produce a single sample value. This summing and averaging happens in
ebradley6 0:286582877314 175 // a variable of type signed long long, to make sure that the data doesn't
ebradley6 0:286582877314 176 // overflow regardless of sample size (8 bits, 16 bits, 32 bits).
ebradley6 0:286582877314 177 //
ebradley6 0:286582877314 178 // note that from what I can find that 8 bit wave files use unsigned data,
ebradley6 0:286582877314 179 // while 16 and 32 bit wave files use signed data
ebradley6 0:286582877314 180 //
ebradley6 0:286582877314 181
ebradley6 1:11a670498598 182 // Fill buffer 0 first
ebradley6 0:286582877314 183 buf0_flag=1;
ebradley6 0:286582877314 184
ebradley6 0:286582877314 185 // Separate slices into sections of BUF_SIZE samples
ebradley6 0:286582877314 186 for (j=0; j<((num_slices/BUF_SIZE)+1); j++)
ebradley6 0:286582877314 187 {
ebradley6 0:286582877314 188 for(k=0; k<BUF_SIZE; k++)
ebradley6 0:286582877314 189 {
ebradley6 0:286582877314 190 // The last buffer will likely not be exactly BUF_SIZE,
ebradley6 0:286582877314 191 // so fill the remaining spots with 0
ebradley6 0:286582877314 192 if((j*BUF_SIZE+k)>num_slices){
ebradley6 0:286582877314 193 if(buf0_flag)
ebradley6 0:286582877314 194 DAC_buf0[k]=0;
ebradley6 0:286582877314 195 else
ebradley6 0:286582877314 196 DAC_buf1[k]=0;
ebradley6 0:286582877314 197 }
ebradley6 0:286582877314 198 else{
ebradley6 1:11a670498598 199 // Read audio samples from sd card
ebradley6 0:286582877314 200 fread(slice_buf,wav_format.block_align,1,wavefile);
ebradley6 0:286582877314 201 if (feof(wavefile)) {
ebradley6 0:286582877314 202 printf("Oops -- not enough slices in the wave file\n");
ebradley6 0:286582877314 203 exit(1);
ebradley6 0:286582877314 204 }
ebradley6 0:286582877314 205 data_sptr=(short *)slice_buf; // 16 bit samples
ebradley6 0:286582877314 206 data_bptr=(unsigned char *)slice_buf; // 8 bit samples
ebradley6 0:286582877314 207 data_wptr=(int *)slice_buf; // 32 bit samples
ebradley6 0:286582877314 208 slice_value=0;
ebradley6 0:286582877314 209 for (channel=0;channel<wav_format.num_channels;channel++) {
ebradley6 0:286582877314 210 switch (wav_format.sig_bps) {
ebradley6 0:286582877314 211 case 16:
ebradley6 0:286582877314 212 if (verbosity)
ebradley6 0:286582877314 213 printf("16 bit channel %d data=%d ",channel,data_sptr[channel]);
ebradley6 0:286582877314 214 slice_value+=data_sptr[channel];
ebradley6 0:286582877314 215 break;
ebradley6 0:286582877314 216 case 32:
ebradley6 0:286582877314 217 if (verbosity)
ebradley6 0:286582877314 218 printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
ebradley6 0:286582877314 219 slice_value+=data_wptr[channel];
ebradley6 0:286582877314 220 break;
ebradley6 0:286582877314 221 case 8:
ebradley6 0:286582877314 222 if (verbosity)
ebradley6 0:286582877314 223 printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
ebradley6 0:286582877314 224 slice_value+=data_bptr[channel];
ebradley6 0:286582877314 225 break;
ebradley6 0:286582877314 226 }
ebradley6 0:286582877314 227 }
ebradley6 0:286582877314 228 slice_value/=wav_format.num_channels;
ebradley6 0:286582877314 229
ebradley6 0:286582877314 230 // slice_value is now averaged. Next it needs to be scaled to an unsigned 16 bit value
ebradley6 0:286582877314 231 // with DC offset so it can be written to the DAC.
ebradley6 0:286582877314 232 switch (wav_format.sig_bps) {
ebradley6 0:286582877314 233 case 8: slice_value<<=8;
ebradley6 0:286582877314 234 break;
ebradley6 0:286582877314 235 case 16: slice_value+=32768;
ebradley6 0:286582877314 236 break;
ebradley6 0:286582877314 237 case 32: slice_value>>=16;
ebradley6 0:286582877314 238 slice_value+=32768;
ebradley6 0:286582877314 239 break;
ebradley6 0:286582877314 240 }
ebradley6 0:286582877314 241
ebradley6 0:286582877314 242 if (verbosity)
ebradley6 0:286582877314 243 printf("sample %d slice_value %d\n",(j*BUF_SIZE+k),(int)slice_value);
ebradley6 0:286582877314 244 if(buf0_flag)
ebradley6 0:286582877314 245 DAC_buf0[k]=(uint32_t)slice_value;
ebradley6 0:286582877314 246 else
ebradley6 0:286582877314 247 DAC_buf1[k]=(uint32_t)slice_value;
ebradley6 0:286582877314 248 }
ebradley6 0:286582877314 249 }
ebradley6 0:286582877314 250
ebradley6 0:286582877314 251 // Except for the first buffer, wait until the previous DMA transfer is
ebradley6 0:286582877314 252 // complete before switching buffers
ebradley6 0:286582877314 253 if(j>0)
ebradley6 0:286582877314 254 {
ebradley6 0:286582877314 255 while((dma0_fin_flag==0)&(dma1_fin_flag==0)&(time<500000000)){
ebradley6 0:286582877314 256 wait_us(1);
ebradley6 0:286582877314 257 time++;
ebradley6 0:286582877314 258 }
ebradley6 0:286582877314 259 }
ebradley6 0:286582877314 260
ebradley6 0:286582877314 261 if (time>499999999)
ebradley6 0:286582877314 262 {
ebradley6 0:286582877314 263 printf("timeout, %d of %d\r\n", (j*BUF_SIZE), num_slices);
ebradley6 0:286582877314 264 exit(1);
ebradley6 0:286582877314 265 }
ebradley6 0:286582877314 266
ebradley6 0:286582877314 267 time=0;
ebradley6 0:286582877314 268 dma0_fin_flag=0;
ebradley6 0:286582877314 269 dma1_fin_flag=0;
ebradley6 0:286582877314 270
ebradley6 0:286582877314 271 // If finished filling buffer 0, set flag to fill buffer 1
ebradley6 0:286582877314 272 // and start the DMA transfer for buffer 0
ebradley6 0:286582877314 273 if(buf0_flag==1)
ebradley6 0:286582877314 274 {
ebradley6 0:286582877314 275 buf0_flag=0;
ebradley6 0:286582877314 276 dma.Setup(conf0);
ebradley6 0:286582877314 277 dma.Enable( conf0 );
ebradley6 0:286582877314 278 }
ebradley6 0:286582877314 279 else // Similarly for buffer 1
ebradley6 0:286582877314 280 {
ebradley6 0:286582877314 281 buf0_flag=1;
ebradley6 0:286582877314 282 dma.Setup(conf1);
ebradley6 0:286582877314 283 dma.Enable( conf1 );
ebradley6 0:286582877314 284 }
ebradley6 0:286582877314 285
ebradley6 0:286582877314 286 }
ebradley6 0:286582877314 287 DAC_on=0;
ebradley6 0:286582877314 288 delete conf0;
ebradley6 0:286582877314 289 delete conf1;
ebradley6 0:286582877314 290 free(slice_buf);
ebradley6 0:286582877314 291 break;
ebradley6 0:286582877314 292 case 0x5453494c:
ebradley6 0:286582877314 293 if (verbosity)
ebradley6 0:286582877314 294 printf("INFO chunk, size %d\n",chunk_size);
ebradley6 0:286582877314 295 fseek(wavefile,chunk_size,SEEK_CUR);
ebradley6 0:286582877314 296 break;
ebradley6 0:286582877314 297 default:
ebradley6 0:286582877314 298 printf("unknown chunk type 0x%x, size %d\n",chunk_id,chunk_size);
ebradley6 0:286582877314 299 data=fseek(wavefile,chunk_size,SEEK_CUR);
ebradley6 0:286582877314 300 break;
ebradley6 0:286582877314 301 }
ebradley6 0:286582877314 302 fread(&chunk_id,4,1,wavefile);
ebradley6 0:286582877314 303 fread(&chunk_size,4,1,wavefile);
ebradley6 0:286582877314 304 }
ebradley6 0:286582877314 305 }
ebradley6 0:286582877314 306
ebradley6 1:11a670498598 307 // Configuration callback on TC; runs when the DMA has finished transferring buffer 0 to the DAC
ebradley6 0:286582877314 308 void wave_player::TC0_callback(void) {
ebradley6 0:286582877314 309
ebradley6 0:286582877314 310 // Get configuration pointer.
ebradley6 0:286582877314 311 MODDMA_Config *config = dma.getConfig();
ebradley6 0:286582877314 312
ebradley6 1:11a670498598 313 // Only run once
ebradley6 0:286582877314 314 dma.haltAndWaitChannelComplete( (MODDMA::CHANNELS)config->channelNum());
ebradley6 0:286582877314 315
ebradley6 0:286582877314 316 // Finish the DMA cycle by shutting down the channel.
ebradley6 0:286582877314 317 dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
ebradley6 0:286582877314 318
ebradley6 0:286582877314 319 // Clear DMA IRQ flags.
ebradley6 0:286582877314 320 if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
ebradley6 0:286582877314 321
ebradley6 0:286582877314 322 // Indicate that buffer 0 has finished transferring
ebradley6 0:286582877314 323 dma0_fin_flag=1;
ebradley6 0:286582877314 324 }
ebradley6 0:286582877314 325
ebradley6 0:286582877314 326 // Configuration callback on Error
ebradley6 0:286582877314 327 void wave_player::ERR0_callback(void) {
ebradley6 0:286582877314 328 error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem");
ebradley6 0:286582877314 329 }
ebradley6 0:286582877314 330
ebradley6 1:11a670498598 331 // Configuration callback on TC; runs when the DMA has finished transferring buffer 1 to the DAC
ebradley6 0:286582877314 332 void wave_player::TC1_callback(void) {
ebradley6 0:286582877314 333
ebradley6 0:286582877314 334 // Get configuration pointer.
ebradley6 0:286582877314 335 MODDMA_Config *config = dma.getConfig();
ebradley6 0:286582877314 336
ebradley6 1:11a670498598 337 // Only run once
ebradley6 0:286582877314 338 dma.haltAndWaitChannelComplete( (MODDMA::CHANNELS)config->channelNum());
ebradley6 0:286582877314 339
ebradley6 0:286582877314 340 // Finish the DMA cycle by shutting down the channel.
ebradley6 0:286582877314 341 dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
ebradley6 0:286582877314 342
ebradley6 0:286582877314 343 // Clear DMA IRQ flags.
ebradley6 0:286582877314 344 if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();
ebradley6 0:286582877314 345
ebradley6 0:286582877314 346 // Indicate that buffer 1 has finished transferring
ebradley6 0:286582877314 347 dma1_fin_flag=1;
ebradley6 0:286582877314 348 }
ebradley6 0:286582877314 349
ebradley6 0:286582877314 350 // Configuration callback on Error
ebradley6 0:286582877314 351 void wave_player::ERR1_callback(void) {
ebradley6 0:286582877314 352 error("Oh no! My Mbed EXPLODED! :( Only kidding, go find the problem");
ebradley6 0:286582877314 353 }