Hi guys,
I've got this task to do but feel like I'm banging my head against the wall a little so would appreciate a bit of input to know I'm heading in the right direction!
This control system counts passengers and gives different outputs depending on the number of passengers
The rough criteria for the system is:
1 - 5 passengers: System ok, green light
> 5 passengers: too many passengers, sound alarm until passengers between 1 and 5
< 0 passengers: sound alarm, phone maintainers
I've decided to use J-K flip flops as an async 3-bit up/down counter to count the passengers, and use momentary push to make switches as the passenger in/out inputs (for simulation purposes in multisim). I've OR'd these inputs into the first J-K flip-flop clock bit. This half works in multisim but not quite, the outputs count 1, 2, then 7, then I get some faults.. This is the circuit, I've deleted the 7-seg display but I use the Q outputs from each J-K to provide the counting sequence:
Any ideas why it's not working? I've never used multisim before so may have missed something..
To determine the output, I've decided to use two 2 to 4 decoders with enable to give a 3 to 8 decoder. I was thinking of commoning outputs resulting from counter inputs 1-5 to give 'system' ok and counter input 6 as 'too many passengers'. I'm not sure about less than 0, any hints as to how I could do this? Was thinking maybe use counter input 7, but I'm not quite sure if this would work as I'd need to get the counter to stop at 6 but go from 0 to 7 when counting down..
I'll be honest here and say I have absolutely no idea how to get a circuit to send a call through a phone, surely I'd need some sort of device with a serial port to connect to a phone or something like that?
Finally, apologies for the essay, and any help/advice would be greatly appreciated! I'm also not 100% sure if the method I've chosen (using the J-K's for a 3-bit up/down and processing the outputs with a 3 to 8 decoder) is the best way to do it, but I think it should work!
Thanks in advance
I've got this task to do but feel like I'm banging my head against the wall a little so would appreciate a bit of input to know I'm heading in the right direction!
This control system counts passengers and gives different outputs depending on the number of passengers
The rough criteria for the system is:
1 - 5 passengers: System ok, green light
> 5 passengers: too many passengers, sound alarm until passengers between 1 and 5
< 0 passengers: sound alarm, phone maintainers
I've decided to use J-K flip flops as an async 3-bit up/down counter to count the passengers, and use momentary push to make switches as the passenger in/out inputs (for simulation purposes in multisim). I've OR'd these inputs into the first J-K flip-flop clock bit. This half works in multisim but not quite, the outputs count 1, 2, then 7, then I get some faults.. This is the circuit, I've deleted the 7-seg display but I use the Q outputs from each J-K to provide the counting sequence:
Any ideas why it's not working? I've never used multisim before so may have missed something..
I'll be honest here and say I have absolutely no idea how to get a circuit to send a call through a phone, surely I'd need some sort of device with a serial port to connect to a phone or something like that?
Finally, apologies for the essay, and any help/advice would be greatly appreciated! I'm also not 100% sure if the method I've chosen (using the J-K's for a 3-bit up/down and processing the outputs with a 3 to 8 decoder) is the best way to do it, but I think it should work!
Thanks in advance