title: Random Number Generation - C on ARM7
body: <p>I need to generate a random number, now this number needs to be somewhere between 10 and 120 seconds.
  Now, in C I could use Random to acomplish this, however I do not have access to that function.
  In an effort to try and be clever I have identified some random data, I have access to a wireless scan function (that this random number is actually eventually required for) which provides me the signal strength of each detected Wi-Fi signal.</p>
  
  <p>Using this I thought I could create a nice random number, however obviously this gives a very large sum which needs to be scaled down somewhat - this reduces the potential difference between different random numbers.</p>
  
  <p>The random number will be used as a backoff timer for different wireless devices trying to interconnect with eachother and obviously as random a figure as I can achieve the better.</p>
  
  <p>Any thoughts? Maybe there is an easier method of achieving this?
  Thanks for any tips.</p>
  
  <p>Edit: To make the post readable!</p>