Yet another implementation of wave function generator

Dependencies:   mbed vt100

A function generator implemented using DAC of KL25Z on FRDM-KL25Z
On 13-Dec-2015 Support for FRDM-K64F added.

Kinetis の DAC を使用したファンクションジェネレータ(以下funcgen)です。
13-Dec-2015 FRDM-K64F のサポートも追加しました。

/media/uploads/Rhyme/funcgen_top.jpg

Generates a 1KHz sin wave of 3.0V (p-p) when started.

The analog signal output is analogOut (PTE30), for the GND I was using GND of J2.

起動直後には 1KHz 3V(p-p) のサイン波を生成しています。

アナログ信号は PTE30 から、 GNDについては、J2 の GNDを使用しています。

This funcgen can generate multiple sin, saw, sqr, tri waves in different freq, amp simultaneously.
All the waves are summed to form the output.

この funcgen では 複数の異なる周期、振幅の正弦波、のこぎり波、矩形波、三角波を同時に生成することが可能です。
生成された波形はすべて加算される形で出力波形となります。

For example following wave form was generated with
sin amp = 0.5V freq = 1000 Hz
sin amp = 0.5V freq = 123 Hz
sqr amp = 0.5V freq = 20 Hz
saw amp = 1.0V freq = 3Hz

たとえば下図の波形は
サイン波 0.5V 1000Hz
サイン波 0.5V 123 Hz
矩形波 0.5V 20Hz
のこぎり波 1.0V 3Hz
を合成して得られたものです。

/media/uploads/Rhyme/summed_output.jpg

Some tutorial (簡単な使い方)

When you connect a terminal program with 115200 baud, 8bit, no parity,
after reset command menu will be presented.
You may also want to enable local echo, so that you can see what you are typing.

ターミナルプログラムで 115200 baud 8bit ノーパリティで接続していると、
リセット後に下記のようなコマンドメニューが表示されます。
入力している文字が表示されるように Local Echo を有効にしておきます。

/media/uploads/Rhyme/startup_menus.jpg

If you type "list" to the prompt, list of current wave(s) will be shown.

プロンプトに list と入力すると、現在の波形リストが表示されます。

/media/uploads/Rhyme/list_cmds.jpg

So we can tell that 1 wave of sine whose amplitude is 3.0V
and Frequency is 1000Hz is currently running.
Please ignore duty for sin and saw waves ;-) 
The "*" letter in the left shows that this signal is currently selected for operation.

これから、1KHz 3V(p-p)の正弦波が生成されていることがわかります。
デューティー比も表示されていますが、正弦波(sin)とのごきり波(saw)に関しては、
これは無視してください。 
また、左側についている“*”マークが、現在この信号がコマンドの対象になっていることを示しています。

At this time the wave form would look like

この時点で波形は下記のようになっています

/media/uploads/Rhyme/sin_3v_1khz.jpg

If you type "amp 1" the wave form will be

ここで amp 1 と入力すると波形は下記のようになります

/media/uploads/Rhyme/sin_1v_1khz.jpg

Next let's play with a square wave!
To remove current wave type "delete", then type "sqr 3 1000 50"
which means first delete the sin wave then add a square wave of 3V, 1KHz and duty 50%.

それでは矩形波で遊んでみましょう!
まず正弦波を消すのに“delete”とタイプして、次に“sqr 3 1000 50” とタイプしてください。
これは3V 1KHz デューティ50%の正弦波の追加することになります。

/media/uploads/Rhyme/add_sqr.jpg

The wave form of Oscilloscope will be something like

オシロの波形は下記のような感じになります

/media/uploads/Rhyme/sqr_3v_1khz_50.jpg

Now if you type "duty 0" you will get

ここで “duty 0” と入力すると

/media/uploads/Rhyme/sqr_3v_1khz_0.jpg

For "duty 20" you will get

“duty 20”では

/media/uploads/Rhyme/sqr_3v_1khz_20.jpg

For "duty 80" you will get

"duty 80" では

/media/uploads/Rhyme/sqr_3v_1khz_80.jpg

And finally if you specify "duty 100", you will get

最後に“duty 100”を指定すると

/media/uploads/Rhyme/sqr_3v_1khz_100.jpg

This way, you can also get DC bias of this sqr wave's amplitude.

この方法で、この矩形波の振幅に等しいDC入力とすることもできます。

Next, let's try "tri wave", again type "delete" and "tri 3 1000 50", you will get

次に三角波行ってみましょう、再び“delete”、“tri 3 1000 50”と入力しますと

/media/uploads/Rhyme/tri_3_1khz_50.jpg

Again if we try, "duty 0", we will get

“duty 0”とすると

/media/uploads/Rhyme/tri_3_1khz_0.jpg

For "duty 20"

"duty 20" では

/media/uploads/Rhyme/tri_3_1khz_20.jpg

For "duty 80"

"duty 80" では

/media/uploads/Rhyme/tri_3_1khz_80.jpg

And finally "duty 100"

最後に "duty 100"

/media/uploads/Rhyme/tri_3_1khz_100.jpg

Please note that for the "duty 100",
the triangle wave is identical with "saw" wave,
which I noticed after implementing both of them orz

“duty 100”の三角波はのこぎり波と同じものになります。 
気が付いたのは両方の波形をプログラムしちゃってからでした・・・ orz

Multiple waves sample  複数波形の合成例

Now let's try multiple wave composition!

それでは複数波形の合成を試してみましょう!

First let's delete the previous wave, by "delete"

最初に先の信号を"delete" で消しておきます。

Then type, "sqr 1 100 50", "sin 1 700", you will get

次に "sqr 1 100 50", "sin 1 700" とすると

/media/uploads/Rhyme/sqr_1_sin_1.jpg

/media/uploads/Rhyme/sqr_1_sin_1_wave.jpg

And adding a saw wave by "saw 1 10" will give us

最後にのこぎり波を "saw 1 10" で追加すると

/media/uploads/Rhyme/sqr_1_sin_1_saw_1_wave.jpg

If we enter "list" command we will see

ここで list コマンドを入力すると

/media/uploads/Rhyme/list_waves.jpg

Note the "*" letter specify the selected wave,
so if you enter "amp", "freq", "duty", "delete" command,
it will be applied to this wave.
If you want to manipulate other wave,
use "select #" command to specify the wave you'd like to modify.
For example, if you enter "select 0" then the sqr wave at No.0 will be selected.

左側の"*"マークが現在選択されている波形を示しています、
現在"amp", "freq", "duty", "delete" などのコマンドを入力した場合、
その操作はこの波形に対して行われます。
他の波形をモディファイしたい場合には"select #" コマンドを使用してその波形を選択してください。
たとえば "select 0" と入力すると 矩形波(sqr)が選択されることになります。

/media/uploads/Rhyme/ojizo_and.jpg

Committer:
Rhyme
Date:
Sun Jan 04 10:21:07 2015 +0000
Revision:
0:46a79748aa81
Child:
1:b4f26ccaf417
commit before publish;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Rhyme 0:46a79748aa81 1 /** mbed funcgen my implementation of a function generator
Rhyme 0:46a79748aa81 2 * Copyright (c) 2014, 2015 Motoo Tanaka @ Design Methodology Lab
Rhyme 0:46a79748aa81 3 *
Rhyme 0:46a79748aa81 4 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Rhyme 0:46a79748aa81 5 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Rhyme 0:46a79748aa81 6 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Rhyme 0:46a79748aa81 7 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Rhyme 0:46a79748aa81 8 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Rhyme 0:46a79748aa81 9 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Rhyme 0:46a79748aa81 10 * THE SOFTWARE.
Rhyme 0:46a79748aa81 11 */
Rhyme 0:46a79748aa81 12
Rhyme 0:46a79748aa81 13 #include "mbed.h"
Rhyme 0:46a79748aa81 14 #include "math.h"
Rhyme 0:46a79748aa81 15 #include "vt100.h"
Rhyme 0:46a79748aa81 16
Rhyme 0:46a79748aa81 17 #include "wave.h"
Rhyme 0:46a79748aa81 18 #include "sinwave.h"
Rhyme 0:46a79748aa81 19 #include "sqrwave.h"
Rhyme 0:46a79748aa81 20 #include "sawwave.h"
Rhyme 0:46a79748aa81 21 #include "triwave.h"
Rhyme 0:46a79748aa81 22
Rhyme 0:46a79748aa81 23 #define MODE_PAUSE 0x00
Rhyme 0:46a79748aa81 24 #define MODE_RUN 0x01
Rhyme 0:46a79748aa81 25
Rhyme 0:46a79748aa81 26 #define MAX_WAVE 10
Rhyme 0:46a79748aa81 27
Rhyme 0:46a79748aa81 28 DigitalOut myled(PTB18) ;
Rhyme 0:46a79748aa81 29 AnalogOut aout(PTE30) ; // SignalOut
Rhyme 0:46a79748aa81 30
Rhyme 0:46a79748aa81 31 Ticker *timer ;
Rhyme 0:46a79748aa81 32 wave *wave_list[MAX_WAVE] ;
Rhyme 0:46a79748aa81 33 wave *w = 0 ;
Rhyme 0:46a79748aa81 34 int num_wave = 0 ;
Rhyme 0:46a79748aa81 35 int wave_index = 0 ;
Rhyme 0:46a79748aa81 36 bool ticked = false ;
Rhyme 0:46a79748aa81 37 int vdout = 0 ;
Rhyme 0:46a79748aa81 38 int avalue = 0 ;
Rhyme 0:46a79748aa81 39 int aindex = 0 ;
Rhyme 0:46a79748aa81 40 int mode = MODE_RUN ;
Rhyme 0:46a79748aa81 41 vt100 *tty = 0 ;
Rhyme 0:46a79748aa81 42
Rhyme 0:46a79748aa81 43 /** usage display list of available commands
Rhyme 0:46a79748aa81 44 */
Rhyme 0:46a79748aa81 45 void usage(void)
Rhyme 0:46a79748aa81 46 {
Rhyme 0:46a79748aa81 47 printf("=== funcgen (%s) ===\n\r", __DATE__) ;
Rhyme 0:46a79748aa81 48 printf("run : start wave generation\n\r") ;
Rhyme 0:46a79748aa81 49 printf("stop : stop wave generation\n\r") ;
Rhyme 0:46a79748aa81 50 printf("help : print this help\n\r") ;
Rhyme 0:46a79748aa81 51 printf("sin <amp> <freq> add a sine wave\n\r") ;
Rhyme 0:46a79748aa81 52 printf("sqr <amp> <freq> <duty> add a square wave\n\r") ;
Rhyme 0:46a79748aa81 53 printf("saw <amp> <freq> add a saw wave\n\r") ;
Rhyme 0:46a79748aa81 54 printf("tri <amp> <freq> <duty> add a triangle wave\n\r") ;
Rhyme 0:46a79748aa81 55 printf("------------------\n\r") ;
Rhyme 0:46a79748aa81 56 printf("list (print list of waves)\n\r") ;
Rhyme 0:46a79748aa81 57 printf("select <num> (select a target wave)\n\r") ;
Rhyme 0:46a79748aa81 58 printf("delete (delete selected wave)\n\r") ;
Rhyme 0:46a79748aa81 59 printf("amp <amp> (0 ~ 3.28 V)\n\r") ;
Rhyme 0:46a79748aa81 60 printf("freq <freq> (0 ~ 12000 Hz)\n\r") ;
Rhyme 0:46a79748aa81 61 printf("duty <duty> (0 ~ 100 %%)\n\r") ;
Rhyme 0:46a79748aa81 62 printf("sample <time> (25~100 us(?))\n\r") ;
Rhyme 0:46a79748aa81 63 printf("------------------\n\r") ;
Rhyme 0:46a79748aa81 64 }
Rhyme 0:46a79748aa81 65
Rhyme 0:46a79748aa81 66 /** tick_time advance wave position(s)
Rhyme 0:46a79748aa81 67 */
Rhyme 0:46a79748aa81 68 void tick_time(void)
Rhyme 0:46a79748aa81 69 {
Rhyme 0:46a79748aa81 70 int i ;
Rhyme 0:46a79748aa81 71 int value = 0 ;
Rhyme 0:46a79748aa81 72 for (i = 0 ; i < num_wave ; i++ ) {
Rhyme 0:46a79748aa81 73 if (wave_list[i]) {
Rhyme 0:46a79748aa81 74 value += wave_list[i]->value() ;
Rhyme 0:46a79748aa81 75 wave_list[i]->advance() ;
Rhyme 0:46a79748aa81 76 }
Rhyme 0:46a79748aa81 77 }
Rhyme 0:46a79748aa81 78 if (value > 0xFFFF) { // clip
Rhyme 0:46a79748aa81 79 value = 0xFFFF ;
Rhyme 0:46a79748aa81 80 }
Rhyme 0:46a79748aa81 81 aout.write_u16(value) ;
Rhyme 0:46a79748aa81 82 }
Rhyme 0:46a79748aa81 83
Rhyme 0:46a79748aa81 84 /** adjust sample time
Rhyme 0:46a79748aa81 85 * For a single wave 25us seems to be sufficient
Rhyme 0:46a79748aa81 86 * but adding more wave seems to require additional
Rhyme 0:46a79748aa81 87 * 8us for each wave function.
Rhyme 0:46a79748aa81 88 * These values are only from my experiments
Rhyme 0:46a79748aa81 89 * so may be there is/are better numbers/solutions.
Rhyme 0:46a79748aa81 90 */
Rhyme 0:46a79748aa81 91 void adjust_sample_time(int newvalue = 0)
Rhyme 0:46a79748aa81 92 {
Rhyme 0:46a79748aa81 93 int i ;
Rhyme 0:46a79748aa81 94 if (timer) {
Rhyme 0:46a79748aa81 95 timer->detach() ;
Rhyme 0:46a79748aa81 96 }
Rhyme 0:46a79748aa81 97 if (newvalue != 0) {
Rhyme 0:46a79748aa81 98 sample_time = newvalue ;
Rhyme 0:46a79748aa81 99 } else {
Rhyme 0:46a79748aa81 100 sample_time = 17 + 8 * num_wave ;
Rhyme 0:46a79748aa81 101 }
Rhyme 0:46a79748aa81 102 for (i = 0 ; i < num_wave ; i++ ) {
Rhyme 0:46a79748aa81 103 if (wave_list[i] != 0) {
Rhyme 0:46a79748aa81 104 wave_list[i]->update() ;
Rhyme 0:46a79748aa81 105 }
Rhyme 0:46a79748aa81 106 }
Rhyme 0:46a79748aa81 107 if (timer && (mode & MODE_RUN)) {
Rhyme 0:46a79748aa81 108 timer->attach_us(&tick_time, sample_time) ;
Rhyme 0:46a79748aa81 109 }
Rhyme 0:46a79748aa81 110 }
Rhyme 0:46a79748aa81 111
Rhyme 0:46a79748aa81 112 void add_wave(wave *w)
Rhyme 0:46a79748aa81 113 {
Rhyme 0:46a79748aa81 114 if (num_wave < MAX_WAVE) {
Rhyme 0:46a79748aa81 115 timer->detach() ;
Rhyme 0:46a79748aa81 116 wave_index = num_wave ;
Rhyme 0:46a79748aa81 117 wave_list[wave_index] = w ;
Rhyme 0:46a79748aa81 118 num_wave++ ;
Rhyme 0:46a79748aa81 119 adjust_sample_time() ;
Rhyme 0:46a79748aa81 120 } else {
Rhyme 0:46a79748aa81 121 printf("Maximum number of waves exceeded\n\r") ;
Rhyme 0:46a79748aa81 122 }
Rhyme 0:46a79748aa81 123 }
Rhyme 0:46a79748aa81 124
Rhyme 0:46a79748aa81 125 void delete_current_wave(void)
Rhyme 0:46a79748aa81 126 {
Rhyme 0:46a79748aa81 127 int i ;
Rhyme 0:46a79748aa81 128 if (wave_list[wave_index] != 0) {
Rhyme 0:46a79748aa81 129 timer->detach() ;
Rhyme 0:46a79748aa81 130 delete wave_list[wave_index] ;
Rhyme 0:46a79748aa81 131 for (i = wave_index ; i < num_wave ; i++ ) {
Rhyme 0:46a79748aa81 132 wave_list[i] = wave_list[i+1] ;
Rhyme 0:46a79748aa81 133 }
Rhyme 0:46a79748aa81 134 num_wave-- ;
Rhyme 0:46a79748aa81 135 wave_list[num_wave] = 0 ;
Rhyme 0:46a79748aa81 136 if (wave_index >= num_wave) {
Rhyme 0:46a79748aa81 137 wave_index = num_wave - 1 ;
Rhyme 0:46a79748aa81 138 }
Rhyme 0:46a79748aa81 139 w = wave_list[wave_index] ;
Rhyme 0:46a79748aa81 140 adjust_sample_time() ;
Rhyme 0:46a79748aa81 141 }
Rhyme 0:46a79748aa81 142 }
Rhyme 0:46a79748aa81 143
Rhyme 0:46a79748aa81 144 void list_waves(void)
Rhyme 0:46a79748aa81 145 {
Rhyme 0:46a79748aa81 146 int i ;
Rhyme 0:46a79748aa81 147 printf("sample time = %d(us) %d wave(s)\n\r", sample_time, num_wave) ;
Rhyme 0:46a79748aa81 148 for (i = 0 ; i < num_wave ; i++ ) {
Rhyme 0:46a79748aa81 149 if (i == wave_index) {
Rhyme 0:46a79748aa81 150 printf("* ") ;
Rhyme 0:46a79748aa81 151 } else {
Rhyme 0:46a79748aa81 152 printf(" ") ;
Rhyme 0:46a79748aa81 153 }
Rhyme 0:46a79748aa81 154 printf("%d: ", i) ;
Rhyme 0:46a79748aa81 155 if (wave_list[i]) {
Rhyme 0:46a79748aa81 156 w = wave_list[i] ;
Rhyme 0:46a79748aa81 157 printf("[ %s ] amp = %.2f V, freq = %d Hz, duty = %d %%",
Rhyme 0:46a79748aa81 158 w->name(), w->volt(), w->freq(), w->duty()) ;
Rhyme 0:46a79748aa81 159 }
Rhyme 0:46a79748aa81 160 printf("\n\r") ;
Rhyme 0:46a79748aa81 161 }
Rhyme 0:46a79748aa81 162 w = wave_list[wave_index] ;
Rhyme 0:46a79748aa81 163 }
Rhyme 0:46a79748aa81 164
Rhyme 0:46a79748aa81 165 /** main funcgen main program
Rhyme 0:46a79748aa81 166 */
Rhyme 0:46a79748aa81 167 int main() {
Rhyme 0:46a79748aa81 168 char cmd[32] ;
Rhyme 0:46a79748aa81 169 int freq, duty ;
Rhyme 0:46a79748aa81 170 float volt ;
Rhyme 0:46a79748aa81 171
Rhyme 0:46a79748aa81 172 tty = new vt100() ;
Rhyme 0:46a79748aa81 173 tty->cls() ;
Rhyme 0:46a79748aa81 174 usage() ;
Rhyme 0:46a79748aa81 175
Rhyme 0:46a79748aa81 176 timer = new Ticker() ;
Rhyme 0:46a79748aa81 177 w = new sinwave(3.0, 1000, 0) ;
Rhyme 0:46a79748aa81 178 add_wave(w) ;
Rhyme 0:46a79748aa81 179
Rhyme 0:46a79748aa81 180 timer->attach_us(&tick_time, sample_time) ;
Rhyme 0:46a79748aa81 181 myled = 1 ; // turn the LED off
Rhyme 0:46a79748aa81 182
Rhyme 0:46a79748aa81 183 while(1) {
Rhyme 0:46a79748aa81 184 printf("> ") ;
Rhyme 0:46a79748aa81 185 scanf("%s", cmd) ;
Rhyme 0:46a79748aa81 186 if (strcmp(cmd, "run") == 0) { // start timer
Rhyme 0:46a79748aa81 187 mode |= MODE_RUN ;
Rhyme 0:46a79748aa81 188 timer->attach_us(&tick_time, sample_time) ;
Rhyme 0:46a79748aa81 189 } else if (strcmp(cmd, "stop") == 0) { // stop timer
Rhyme 0:46a79748aa81 190 mode ^= MODE_RUN ;
Rhyme 0:46a79748aa81 191 timer->detach() ;
Rhyme 0:46a79748aa81 192 } else if (strcmp(cmd, "delete") == 0) { // delete current wave
Rhyme 0:46a79748aa81 193 delete_current_wave() ;
Rhyme 0:46a79748aa81 194 } else if (strcmp(cmd, "select") == 0) { // select a wave to be handled
Rhyme 0:46a79748aa81 195 scanf("%d", &wave_index) ;
Rhyme 0:46a79748aa81 196 if (wave_index >= num_wave) {
Rhyme 0:46a79748aa81 197 wave_index = num_wave - 1;
Rhyme 0:46a79748aa81 198 }
Rhyme 0:46a79748aa81 199 w = wave_list[wave_index] ;
Rhyme 0:46a79748aa81 200 } else if (strcmp(cmd, "sample") == 0) { // set time unit
Rhyme 0:46a79748aa81 201 scanf("%d", &sample_time) ;
Rhyme 0:46a79748aa81 202 adjust_sample_time(sample_time) ;
Rhyme 0:46a79748aa81 203 } else if (strcmp(cmd, "sin") == 0) { // new sin wave
Rhyme 0:46a79748aa81 204 scanf("%f %d", &volt, &freq) ;
Rhyme 0:46a79748aa81 205 w = new sinwave(volt, freq) ;
Rhyme 0:46a79748aa81 206 add_wave(w) ;
Rhyme 0:46a79748aa81 207 } else if (strcmp(cmd, "sqr") == 0) { // new sqr wave
Rhyme 0:46a79748aa81 208 scanf("%f %d %d", &volt, &freq, &duty) ;
Rhyme 0:46a79748aa81 209 w = new sqrwave(volt, freq, duty) ;
Rhyme 0:46a79748aa81 210 add_wave(w) ;
Rhyme 0:46a79748aa81 211 } else if (strcmp(cmd, "saw") == 0) { // new saw wave
Rhyme 0:46a79748aa81 212 scanf("%f %d", &volt, &freq) ;
Rhyme 0:46a79748aa81 213 w = new sawwave(volt, freq) ;
Rhyme 0:46a79748aa81 214 add_wave(w) ;
Rhyme 0:46a79748aa81 215 } else if (strcmp(cmd, "tri") == 0) { // new tri wave
Rhyme 0:46a79748aa81 216 scanf("%f %d %d", &volt, &freq, &duty) ;
Rhyme 0:46a79748aa81 217 w = new triwave(volt, freq, duty) ;
Rhyme 0:46a79748aa81 218 add_wave(w) ;
Rhyme 0:46a79748aa81 219 } else if (strcmp(cmd, "amp") == 0) {
Rhyme 0:46a79748aa81 220 scanf("%f", &volt) ;
Rhyme 0:46a79748aa81 221 if (w != 0) {
Rhyme 0:46a79748aa81 222 w->volt(volt) ;
Rhyme 0:46a79748aa81 223 }
Rhyme 0:46a79748aa81 224 } else if (strcmp(cmd, "freq") == 0) {
Rhyme 0:46a79748aa81 225 scanf("%d", &freq) ;
Rhyme 0:46a79748aa81 226 if (w != 0) {
Rhyme 0:46a79748aa81 227 w->freq(freq) ;
Rhyme 0:46a79748aa81 228 }
Rhyme 0:46a79748aa81 229 } else if (strcmp(cmd, "duty") == 0) {
Rhyme 0:46a79748aa81 230 scanf("%d", &duty) ;
Rhyme 0:46a79748aa81 231 if (w != 0) {
Rhyme 0:46a79748aa81 232 w->duty(duty) ;
Rhyme 0:46a79748aa81 233 }
Rhyme 0:46a79748aa81 234 } else if (strcmp(cmd, "list") == 0) {
Rhyme 0:46a79748aa81 235 list_waves() ;
Rhyme 0:46a79748aa81 236 } else if (strcmp(cmd, "help") == 0) {
Rhyme 0:46a79748aa81 237 usage() ;
Rhyme 0:46a79748aa81 238 } else {
Rhyme 0:46a79748aa81 239 usage() ;
Rhyme 0:46a79748aa81 240 }
Rhyme 0:46a79748aa81 241 }
Rhyme 0:46a79748aa81 242 }