the only pic I found is the 16F84
I need five (5) inputs, four (4) for 4 bits of data from the decimal-to-bcd encoder*, and one (1) as a "pressing notifier" (for 0000 input at the 4 bits of data).
I need seven (7) outputs, four (4) for bcd output function, and one (1) for each (three total (3) ) latch enabled input of the drivers.
the idea is like this:
- Keyboard, with 10 button
- Decimal-to-bcd encoder
- Three seven segment leds.
- Three 4511 or 4543 display drivers (right, center and left). These drivers are latched at their inputs. The lacth function is controlled by a LT pin. (low for latch enabled). They have another interesting feature: they output blank when the input is 1010,1011,1100,1101,1110,1111.
- One circuit, including pic16f84
Counter A=0
1.- When circuitry is turned on, pic sends to its otputs pins "1111", the displays show blank, and then the pic activate the latch function of the drivers.
1.- pressing a button in the keyboard. The button is encoded in bcd code, and this code appears at the input of the pic. The pic reads this input, thanks to the "pressing notifier" signal.
2.- the pic disables the latch function of the display on the right, and sends to itself otputs the bcd number that was entered at its input. When the driver shows the number entered, the pic activate again the latch function of that driver. A=1
A<3, continue.
3.- pressing a button in the keyboard. the pic receives the number in bcd code and performs two operations: (a) deactivates the latch in the center driver and sends the first bcd number entered in 2.- to its output. Then, when the center driver shows the number, the pic activates the latch function of that, and b) repeat 2.- with the number at its input. Two numbers are shown in the displays. A=2
A<3, continue
4.- pressing a button in the keyboard. the pic receives the number in bcd code and performs the same operations shown above, first with the left driver, then with the center driver and then with the right driver. Three numbers are shown in the displays
(I hope this! :roll
A=3
A=3, is not possible to enter more bcd numbers to the drivers. The reset function send the program to 1.-
It will be possible that dream
? ( = How can I translate this algorithm to a program? or. can I? )
NOTE:
* the "Decimal-to-bcd encoder" encodes the input button entered at keyboard, into a bcd code of 4 bits. I make an experimental one made only of 1n4148 diodes and it works perfectly!.