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POParse four bytes to floating-point in C
 

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  1. POParse four bytes to floating-point in C
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    <p>How do I take four received data <em>bytes</em> and assemble them into a <em>floating-point</em> number?</p> <p>Right now I have the <em>bytes</em> stored in an array, which would be, <strong>received_data[1]</strong> ... <strong>received_data[4]</strong>. I would like to store these four <em>bytes</em> as a single 32-bit single precision <em>float</em>. </p> <p>-Thanks</p> <p>I'm actually receiving a packet with 19 bytes in it and assembling two sets of four bytes to make two floating-point numbers. So <strong>received_data[1]</strong> to <strong>received_data[4]</strong> is one float, and <strong>received_data[5]</strong> to <strong>received_data[8]</strong> is the other...</p> <p><strong>*UPDATE:**** **More Info...</strong><br> The first <em>bit</em>, or the <strong>sign</strong> bit of the <em>float</em>, is the seventh bit the the first <em>byte</em>, here's what I did to check... </p> <pre><code>#define CHECK_BIT(var,pos) ((var) &amp; (1&lt;&lt;(pos))) if( CHECK_BIT(received_data[1], 7)) //set or clear LED2 {LATAbits.LATA2=1;}else{LATAbits.LATA2=0;} if( CHECK_BIT(received_data[5], 7)) //set or clear LED3 {LATAbits.LATA3=1;}else{LATAbits.LATA3=0;} </code></pre> <p>I then checked this by sending alternating positive and negative numbers from my data source, which should have changed the LED's accordingly and it worked. </p> <p>As long as all that holds true, that means the bytes are in the right order, but they are stored little-endian, correct? Will this be stored into the float in the right order? I haven't had any luck parsing the bytes and reading it as a float yet...</p> <p><em>If anyone has any experience with it, I'm using the C18 MPLAB IDE compiler.</em> </p> <p><strong><em>FINAL UPDATE:</em></strong><br> I have my application running! Just some minor bug fixes now!</p> <p><strong><em>THANKS!</em></strong> </p> <p><em>Thanks for all the help guys! I'm new to stackoverflow, but this community on here is truly awesome! And a tool like this is truly priceless! I can not even begin to tell you how much time and frustration you have all saved me!</em></p>
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    1. COIt would be received_data[0] ... received_data[3]. 0-index!
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    2. COI'm actually receiving a packet with 19 bytes in it and assembling two sets of four bytes to make to floating-point numbers. So received_data[1] to received_data[4] is one float, and received_data[5] to received_data[9] is the other...
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