Bloodninja
New Member
Hello everyone,
I'm working on my graduation project, and I decided to design a parking lot system, I attached the circuit to this post as I've completed about 50% of it.
My problem is I want to use the 74LS192D (BCD Up/Down Counter) as an Up counter when the Switch is open (I want to use LDR and a Laser later) then the counter goes up by one. Similar thing will happen at the exit and the counter goes down by 1. the issues are:
- How can I freeze my up counter at 9 for it to wait for someone else to exit ? (I thought about diode AND logic but simulation program (Multisim) refuses)
- 74LS192D counts Up only when DOWN is HIGH...and counts Down when UP is high...I'm confused and troubled with this issue...
I have attached an image and a Multisim file.
Your help is very appreciated
Thanks in advance.
Notes:
the LED at the enterance symbolize the motor direction, nothing more.
I'm working on my graduation project, and I decided to design a parking lot system, I attached the circuit to this post as I've completed about 50% of it.
My problem is I want to use the 74LS192D (BCD Up/Down Counter) as an Up counter when the Switch is open (I want to use LDR and a Laser later) then the counter goes up by one. Similar thing will happen at the exit and the counter goes down by 1. the issues are:
- How can I freeze my up counter at 9 for it to wait for someone else to exit ? (I thought about diode AND logic but simulation program (Multisim) refuses)
- 74LS192D counts Up only when DOWN is HIGH...and counts Down when UP is high...I'm confused and troubled with this issue...
I have attached an image and a Multisim file.
Your help is very appreciated
Thanks in advance.
Notes:
the LED at the enterance symbolize the motor direction, nothing more.