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Altera_Forum
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8 years ago

VHDL Code For Ultrasonic Distance Sensor HC-SR04

I am trying to write the VHDL code for it but it is not working, it shows always 00 ( cm1 = 0 and cm0 = 0). Can you pleaseee help me? Do you detect any problem in the code: Summation of how the...
Altera_Forum's avatar
Altera_Forum
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8 years ago

Well, for a start, you have the following structure: 


if echo = '1' then
  if echo  = '0' then
    --this is impossible, as echo cannot be '1' and '0' at the same time

This case will never occur.

If you have a "working" simulation, but it's not working in hardware, then I suggest there is something wrong with how you're testing your code. Maybe you misunderstood how the echo works? or how some other interface should work?