Help required in forming a binary sequence

Hello,

The overall concept on this piece of code is to transmit a message that comprises words (decimal numbers with a range -127 to 128). To do this, I need to

1. Encode each word in its binary/two's complement (8-bit + Even parity bit) format
2. Concatenate the binary equivalent of the words to be transmitted to form a binary sequence
3. Send the binary sequence through a binary transmission channel
4. On the receiver, I need to do some error checking by assessing the parity bit
5. Decode the binary sequence to yield the message

I am currently facing a problem with the No. 2 (concatenate the binary equivalent of the words) and I would be grateful for any advice you can provide on its syntax.

Here is my code so far - (I built up the code for No. 1 & 5 myself. Although it works, you may find that it is inefficient in terms of the number of lines for its implementation; hence, I will be grateful for any advice to improve its implementation)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

// Define the class for binary sequence
class bin_seq;

// Define the class for word 
class word
{
	private:
		int bit1, bit2, bit3, bit4, bit5, bit6, bit7, bit8, parity;

	public:
		word();
		word(int u);
		~word();
		void Print();
		bool check_parity_OK();
		int DAC();
		friend class bin_seq;
};

// Constructor for word that initialises its data
word::word()
{
	bit1 = 0;
	bit2 = 0;
	bit3 = 0;
	bit4 = 0;
	bit5 = 0;
	bit6 = 0;
	bit7 = 0;
	bit8 = 0;
	parity = 0;
}

// Constructor for word that sets the values for the bits
word::word(int u)
{
	// Clip voltage if it is outside the range
	if (u > 127)
	{
		u = 127;
	}
	if (u < -128)
	{
		u = -128;
	}

	// Implement two's complement encoding
	// First, implement the binary equivalent
	int data = abs(u);
	int i = 0;
	int bit[] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
	while (data != 0)
	{
		bit[i] = data%2;
		data = data/2;
		i = i + 1;
	}

	if (u >= 0)
	{
		// Assign positive words their binary representation 
		bit1	=	bit[0];
		bit2	=	bit[1];
		bit3	=	bit[2];
		bit4	=	bit[3];
		bit5	=	bit[4];
		bit6	=	bit[5];
		bit7	=	bit[6];
		bit8	=	bit[7];
	}

	if (u < 0)
	{
		// Assign negative words their two's complement
		// First, invert the bits
		// Invert bit 1
		if (bit[0]==0)
			bit1 = 1;
		else
			bit1 = 0;

		//Invert bit2
		if (bit[1]==0)
			bit2 = 1;
		else
			bit2 = 0;

		//Invert bit3
		if (bit[2]==0)
			bit3 = 1;
		else
			bit3 = 0;
		
		//Invert bit4
		if (bit[3]==0)
			bit4 = 1;
		else
			bit4 = 0;
		
		//Invert bit5
		if (bit[4]==0)
			bit5 = 1;
		else
			bit5 = 0;
		
		//Invert bit6
		if (bit[5]==0)
			bit6 = 1;
		else
			bit6 = 0;
		
		//Invert bit7
		if (bit[6]==0)
			bit7 = 1;
		else
			bit7 = 0;

		//Invert bit8
		if (bit[7]==0)
			bit8 = 1;
		else
			bit8 = 0;
		
		//Second, add one to the inverter binary word
		//Add one to bit1
		if ((bit1+1)==2)
			bit1 = 0;
		else
			bit1 = 1;

		//Add one to bit2, if required
		if (bit1==0)
			bit2 = bit2+1;
		else
			bit2 = bit2;
		if (bit2==2)
			bit2 = 0;

		//Add one to bit3, if required
		if ((bit1==0)&&(bit2==0))
			bit3 = bit3+1;
		else
			bit3 = bit3;
		if (bit3==2)
			bit3 = 0;

		//Add one to bit4, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0))
			bit4 = bit4+1;
		else
			bit4 = bit4;
		if (bit4==2)
			bit4 = 0;

		//Add one to bit5, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0))
			bit5 = bit5+1;
		else
			bit5 = bit5;
		if (bit5==2)
			bit5 = 0;

		//Add one to bit6, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0))
			bit6 = bit6+1;
		else
			bit6 = bit6;
		if (bit6==2)
			bit6 = 0;

		//Add one to bit7, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0)&&(bit6==0))
			bit7 = bit7+1;
		else
			bit7 = bit7;
		if (bit7==2)
			bit7 = 0;

		//Add one to bit8, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0)&&(bit6==0)&&(bit7==0))
			bit8 = bit8+1;
		else
			bit8 = bit8;
		if (bit7==2)
			bit8 = 0;
	}

	// Set Parity bit
	if ((bit1+bit2+bit3+bit4+bit5+bit6+bit7+bit8)%2 == 0)
		parity = 0;
	else
		parity = 1;
}

// Destructor for word that sets all its bits to zero
word::~word()
{
	bit1 = 0;
	bit2 = 0;
	bit3 = 0;
	bit4 = 0;
	bit5 = 0;
	bit6 = 0;
	bit7 = 0;
	bit8 = 0;
	parity = 0;
}

// Define a print function to display binary sequence
void word::Print()
{
	cout << "(" << parity << bit8 << bit7 << bit6 << bit5 << bit4 << bit3 << bit2 << bit1 << ")" << endl;
}

// Define the Check Parity Bit Function
bool word::check_parity_OK()
{
	bool answer;

	if ((parity==0)&&(bit1+bit2+bit3+bit4+bit5+bit6+bit7+bit8)%2 == 0)
	{
		answer = true;
	}

	if ((parity==0)&&(bit1+bit2+bit3+bit4+bit5+bit6+bit7+bit8)%2 != 0)
	{
		answer = false;
	}

	if ((parity==1)&&(bit1+bit2+bit3+bit4+bit5+bit6+bit7+bit8)%2 != 0)
	{
		answer = true;
	}

	if ((parity==1)&&(bit1+bit2+bit3+bit4+bit5+bit6+bit7+bit8)%2 == 0)
	{
		answer = false;
	}
	
	if (answer == true)
		cout << "Parity OK?: " << "Yes" << endl;
	else
		cout << "Parity OK?: " << "No" << endl;

	return answer;
}

// Define the Digital to Analogue Converter Function
int word::DAC()
{
	int value;

	if (bit8 == 0)
	{
		cout << "The word is a positive integer" << endl;

		//Calculate the decimal equivalent of the binary word
		value = (bit8*pow(2.0,7.0))+(bit7*pow(2.0,6.0))+(bit6*pow(2.0,5.0))+(bit5*pow(2.0,4.0))+(bit4*pow(2.0,3.0))+(bit3*pow(2.0,2.0))+(bit2*pow(2.0,1.0))+(bit1*pow(2.0,0.0));
	}
	else
	{
		cout << "The word is a negative integer" << endl;

		//Convert to the decimal equivalent of the binary word
		//First, invert the bits
		//Invert bit1
		if (bit1==0)
			bit1 = 1;
		else
			bit1 = 0;

		//Invert bit2
		if (bit2==0)
			bit2 = 1;
		else
			bit2 = 0;

		//Invert bit3
		if (bit3==0)
			bit3 = 1;
		else
			bit3 = 0;

		//Invert bit4
		if (bit4==0)
			bit4 = 1;
		else
			bit4 = 0;

		//Invert bit5
		if (bit5==0)
			bit5 = 1;
		else
			bit5 = 0;

		//Invert bit6
		if (bit6==0)
			bit6 = 1;
		else
			bit6 = 0;

		//Invert bit7
		if (bit7==0)
			bit7 = 1;
		else
			bit7 = 0;

		//Invert bit8
		if (bit8==0)
			bit8 = 1;
		else
			bit8 = 0;

		//Second, Add one to the inverted binary word
		//Add one to bit1
		if ((bit1+1)==2)
			bit1 = 0;
		else
			bit1 = 1;

		//Add one to bit2, if required
		if (bit1==0)
			bit2 = bit2+1;
		else
			bit2 = bit2;
		if (bit2==2)
			bit2 = 0;

		//Add one to bit3, if required
		if ((bit1==0)&&(bit2==0))
			bit3 = bit3+1;
		else
			bit3 = bit3;
		if (bit3==2)
			bit3 = 0;

		//Add one to bit4, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0))
			bit4 = bit4+1;
		else
			bit4 = bit4;
		if (bit4==2)
			bit4 = 0;

		//Add one to bit5, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0))
			bit5 = bit5+1;
		else
			bit5 = bit5;
		if (bit5==2)
			bit5 = 0;

		//Add one to bit6, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0))
			bit6 = bit6+1;
		else
			bit6 = bit6;
		if (bit6==2)
			bit6 = 0;

		//Add one to bit7, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0)&&(bit6==0))
			bit7 = bit7+1;
		else
			bit7 = bit7;
		if (bit7==2)
			bit7 = 0;

		//Add one to bit8, if required
		if ((bit1==0)&&(bit2==0)&&(bit3==0)&&(bit4==0)&&(bit5==0)&&(bit6==0)&&(bit7==0))
			bit8 = bit8+1;
		else
			bit8 = bit8;
		if (bit7==2)
			bit8 = 0;

		//Calculate the decimal equivalent of the binary word
		value = -1*((bit8*pow(2.0,7.0))+(bit7*pow(2.0,6.0))+(bit6*pow(2.0,5.0))+(bit5*pow(2.0,4.0))+(bit4*pow(2.0,3.0))+(bit3*pow(2.0,2.0))+(bit2*pow(2.0,1.0))+(bit1*pow(2.0,0.0)));
	}

	return value;
}

// Define the class for Binary Sequence
class bin_seq
{
	private:
		int bits_for_word;

	public:
		bin_seq();
		~bin_seq();
		friend bin_seq get_all_bits();
};

bin_seq::bin_seq()
{

}

// Define the class for message
class message
{
	private:
		int a_word;

	public:
		message(int *words);
		message();
		~message();
		bin_seq get_all_bits();
};

message::message(int *words)
{

}

int main ()
{
	int ans1 = 112;
	int ans2 = -75;
	bool logic1, logic2;
	int result1, result2;

	word voltage;
	voltage.Print();

	word check1(ans1);
	check1.Print();
	logic1 = check1.check_parity_OK();
	//cout << logic1 << endl;
	result1 = check1.DAC();
	cout << result1 << endl;

	cout << endl;

	word check2(ans2);
	check2.Print();
	logic2 = check2.check_parity_OK();
	//cout << logic2 << endl;
	result2 = check2.DAC();
	cout << result2 << endl;

	cin.sync();
	cin.get();
	return 0;
}
Last edited on
Hmm, anything wrong with using 8 bit int in a character array?

Can send/receive the entire message with a single function.
Last edited on
Hello Turbine,

I'd be grateful if you could elaborate a bit more on using an 8-bit integer in a character array. My initial thoughts are how would an 8-bit integer fit inside a character array; isn't that conflicting variable type definitions?

What is the format of the function you had in mind when you suggest "You can send/receive the entire message with a single function"?

I hoped to achieve the formation of the binary sequence by concatenating the bits for a word; I'd also be grateful for some advice along this path I plan to thread.
Topic archived. No new replies allowed.