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go to https://www.electronicspoint.com/general-electronics-chat-f83.html and you would find button sort of ... just as shown in pic... click it, and u can start the thread
rather leave all that start by clicking here https://www.electronicspoint.com/newthread.php?do=newthread&f=83
rather leave all that start by clicking here https://www.electronicspoint.com/newthread.php?do=newthread&f=83
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The BUSY line of the ICL7135 has no output
hello, i draw a circuit according from the datasheet of the ICL7135(see attachment), but the BUSY line of the ICL7135 has no output, i dont konw why, could you help me to solve this problem? thanks!
some parameters as follows: input=1.4567V, Vref=1.0V, clock=120KHZ.
hello, i draw a circuit according from the datasheet of the ICL7135(see attachment), but the BUSY line of the ICL7135 has no output, i dont konw why, could you help me to solve this problem? thanks!
some parameters as follows: input=1.4567V, Vref=1.0V, clock=120KHZ.
I presume you mean that pin 21 is never seen to go high?
Are you using an oscilloscope to look at this pin?
I would suggest a logic probe with an indicator that shows pulses. If the pulses are narrow and infrequent they may be very hard to see on an oscilloscope.
Are you using an oscilloscope to look at this pin?
I would suggest a logic probe with an indicator that shows pulses. If the pulses are narrow and infrequent they may be very hard to see on an oscilloscope.
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Unless you set the scope to trigger on that input.
In an extreme case, you can put the scope in "Normal" mode, set the trigger close to the nominal value of the signal and set the time scale to a pretty low time value. Once you see the pulses, you can then back away until you get a clearer bigger picture.
Otherwise I agree that you can not look at the signal pins of an IC with a multimeter.
---55p
yes,u r right! the pin 21 is never seen to go high. i use the virtual digital oscilloscope (ISIS of proteus) to display the pin21. and i set the resolution of the scope 0.5us. from the scope, i can't see any change in the pin21. but with your suggestion, i put a logicprobe in the pin21 , some surprised thing happened, the probe has two states of 0 or 1. i just feel a little surprised. and i wonder what happened to the pin21?
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So you saw pulses with the logic probe?
It might help if you tell us *why* you were surprised.
The issue with the scope is that unless it is a storage scope that can display trace *before* the trigger, a sufficiently narrow trigger pulse is going to be either invisible or completely mashed up against the left hand side of the display.
It might help if you tell us *why* you were surprised.
The issue with the scope is that unless it is a storage scope that can display trace *before* the trigger, a sufficiently narrow trigger pulse is going to be either invisible or completely mashed up against the left hand side of the display.
So you saw pulses with the logic probe?
It might help if you tell us *why* you were surprised.
The issue with the scope is that unless it is a storage scope that can display trace *before* the trigger, a sufficiently narrow trigger pulse is going to be either invisible or completely mashed up against the left hand side of the display.
yes, once i use the logic probe, there exists change in the pin21. what i want is to get the AD result into the MCU through the BUSY of ICL7135. i draw the circuit, when i stimulate the circuit, the circuit doesn't work. so , i add a virtual scope to the pin21, and i find that the pin21 has no change. if the pin21 has no change ,the INTO will not be interrupted. according from the datasheet of the ICL7135, i can get the AD result from the pin21. because the AD result is related with the number of the clocks of the ICL7135. so ,what the only thing i should do is to count the number of the clocks by the T0 of the MCU. i dont know whether i express my problem clearly. the attchment will make an explaination to you.
thanks for your time!
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It would be a little easier if you can just attach jpg images directly rather than zipping them first.
Counting clocks is a bad idea.
You say that you see the AD pin change state using a logic probe. Does it trigger an interrupt on your uC?
If it doesn't then that is what you need to investigate next. It may be that the AD pulse is too narrow, or that the uC is not programmed correctly to react to the interrupt.
Counting clocks is a bad idea.
You say that you see the AD pin change state using a logic probe. Does it trigger an interrupt on your uC?
If it doesn't then that is what you need to investigate next. It may be that the AD pulse is too narrow, or that the uC is not programmed correctly to react to the interrupt.
the attchment is c code i write, could u plz help me to look at it?
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I can't comment too much on your code. It looks like the interrupt routine should do something, and the body of the code looks like it has the structure I'd expect (other than the place you reset the flag -- but it should still work)
I can't comment on whether you're setting up the interrupt correctly though.
Have you thought of writing some simple code that toggles and output whenever it gets an interrupt? that way you would have an indication of whether or not the interrupts are being seen without having to test all the other code.
I can't comment on whether you're setting up the interrupt correctly though.
Have you thought of writing some simple code that toggles and output whenever it gets an interrupt? that way you would have an indication of whether or not the interrupts are being seen without having to test all the other code.
