Hello, I am trying to make a Serial-in Parallel-out shift Register to be controlled by my PC with logic gates and a 74164, 74193, 555 timer. I am programming it through visual basic and I have no problem making the serial communication, I even made a chat (in a prior application) with it and the data is sent correctly but I'm having some issues with receiving the data and keeping it with the logic. The idea is being able to control the data I output to then control a stepper motor or anything else.
This is the circuit I have developed so far, the 555 timer has 10,200 hz frequency the serial communication is 9600 bauds, 8 data bits, 1 start bit, 1 stop bit, the counter is going to stop at 9 and the clock is going to be activated when a 0 logic so it is starting when the start bit arrives. I have a NAND flip flop to store when to start and it is going to be deactivated when the counter reaches 9, the problem is it is really bugged and I am not sure why it is, when I send any data the 74164 displays 127 or 63 in decimal (0111 1111 and 0011 1111 respectively) and I would like to see if you could give me some hint on it. I did the simulation using a 1hz 555 timer and changing the values by myself and it stopped after the nine bits that is why I would like to see what do you think is going wrong on the circuit. I have not been given a prior circuit to work with but I have used all these IC's (NAND memory, 555 oscillator, 74193 counter) except for the 74164 but I had done a shift register using 74174 so you have an idea of my background regarding digital electronics. The assignement says ¨Create a serial to parallel converter using digital electronics knowledge". Thank you for reading!
This is the circuit I have developed so far, the 555 timer has 10,200 hz frequency the serial communication is 9600 bauds, 8 data bits, 1 start bit, 1 stop bit, the counter is going to stop at 9 and the clock is going to be activated when a 0 logic so it is starting when the start bit arrives. I have a NAND flip flop to store when to start and it is going to be deactivated when the counter reaches 9, the problem is it is really bugged and I am not sure why it is, when I send any data the 74164 displays 127 or 63 in decimal (0111 1111 and 0011 1111 respectively) and I would like to see if you could give me some hint on it. I did the simulation using a 1hz 555 timer and changing the values by myself and it stopped after the nine bits that is why I would like to see what do you think is going wrong on the circuit. I have not been given a prior circuit to work with but I have used all these IC's (NAND memory, 555 oscillator, 74193 counter) except for the 74164 but I had done a shift register using 74174 so you have an idea of my background regarding digital electronics. The assignement says ¨Create a serial to parallel converter using digital electronics knowledge". Thank you for reading!