# Reading mutliple digits binary number, digit by digit

Discussion in 'The Projects Forum' started by cjtk, Apr 4, 2009.

1. ### cjtk Thread Starter New Member

Apr 4, 2009
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0
Hi, I am new to electronics and this forum, currently I am working on a project but stuck at the step where I need to read and process a long binary number.

The binary number is read digit by digit, for 1011 I will receive binary signals of 1,0,1,1, one after another, after receiving one signal there will be a short break until I receive the next one. I am planning to read those four signals into a full adder, so each digit will be read into its coressponding position in the full adder. But since all signals come from the same part of the circuit, I don't know how to manipulate them so that each signal will go to a different part of the full adder. Can anyone help me? thx

2. ### Wendy Moderator

Mar 24, 2008
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What you need is a serial to parallel shift register. Unfortunately the .pdf function on the computer is screwed, so I can't look one up, but they come in chip form. Basically the take the bits and toggle down a serial register, then you can read them in parallel form when a strobe is given. You will need to derive a clock for the serial shift register, and, using the clock, a strobe for the latch the serial register is feeding.

3. ### cjtk Thread Starter New Member

Apr 4, 2009
3
0
Ok, the binary numbers are from sound signals, after looking at serial to parallel shift register, my plan is when a suitable sound signal is detected, send a signal into the clock part of the shift register, then at the same time, decode the sound signal to determine if it is 0 or 1, then send the coressponding signal to the "data in" part of the shift register. Then connect each output to a different input in the full adder.

4. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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Could you post a diagram of the full application? I didn't quite understand this part: "decode the sound signal to determine if it is 0 or 1".

5. ### cjtk Thread Starter New Member

Apr 4, 2009
3
0

So if the transmitters send sound signal of 1,1,0 and 1, that means the binary number is 1011, and i must be able to add this binary number onto a pre programmed binary number within the toy car

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6. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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Do you already have the circuit that verifies the audio received is a valid signal, then decodes it as a 0 or 1 completed?

The output of that circuit should be two lines, such as "output" and "Data Good". i.e. Data and Clock.

When a bit is received and decoded, the data line is set to 1 or 0, and the data good/ready/clock line is pulsed. This then triggers the shift register to shift the bit in. The clock only stays high a short period. When the next bit is available, it is clocked into the shift register, etc.

Send the data good line from receiver to clock a divide by 4 counter to time the rest of the circuit (adder).