Class output statistics circuit

The operating voltage of the main control chip AT89LV51 microcontroller
is 2. 6-6V. Due to the limited on-chip RAM capacity
, a piece of SRAM6264 was added.
LCD1 is a 20×4 character liquid crystal display module
, and Gl is a photoelectric switch (× in 20×4
is the multiplication sign. Gl is above G). When working,
when a product passes through, the P33 pin receives a
negative pulse, and the microcontroller counts the products
and displays them on the LCD screen . When powered on for the first time
, the LCD screen displays as
shown in Figure 7-52a. The first line shows the current time
at 12:00 on August 19, 2005 , and
the 000000 in the second line indicates that the current output is 0. The maximum output
count can reach 999999. symbol? Indicates
that the current group has not been selected yet. When a certain
team goes to work. Press the group selection key
"SBI", frog*. " will change to A. Press
SB1 continuously to cycle through groups A, B, C, and
D. After selecting the group, press OK key SB2,
"? "will become"! ”, indicating that the group selection is
successful. At this time, the output is automatically cleared
to prepare for the work of the group. When the group is off work,
it can press the save key SB7 to save the data. In order to
avoid misuse and waste of RAM, this device also There
are operation prompts. The specific method is: press
SB7 once, and the screen will display: "Save
no!". If you do not want to save, you can press
SB7 again to return to the original display state; if
you want to save the data, press AN4. The display
changes to: “Save yes. If you still don’t
want to save, don’t press any keys. It will automatically return to the original display state after 1Os. Do not save the data; if you really want to save the data, click
SB7, and the start time, end time, group, and output of the group's work will be stored in IC3 6264. Before each storage, the microcontroller must check
whether the memory is full. When only the last three data can be stored, P34 becomes low level. When the music circuit is turned on , an alarm will sound, prompting you
to copy the data quickly, otherwise, when the memory is used up. The oldest stored data will be overwritten. When alarming, press SB2 to stop the alarm, and
other functions will not be affected. After saving, the group on the screen becomes one again? ”, the output becomes “oooooo’, and we are ready for other teams to work
. SB3 is the time key. Connect SB3, "minute" flashes on the screen. Press SB4 to change the minute value.
Connect SB3 again, "hour" flashes. Connect SB4 to adjust the time. Use the same method to correct the year, month, and day, and then press SB3. It can be seen that the edge is accurate.
SB5 and SB6 are query keys. When you need to check the output, press SB5. The work status of each team group will appear on the screen, showing two shifts on one screen
. Press SB5 continuously to query from front to back. When there is valid data in the backend, the screen displays “-End-”. Connect SB6 to query from back to front
. Connect SBZ to exit the query state. SB8 is the clear key. When you need to clear the currently saved data, click SB8. The screen displays
NClear no!r. At this time, you can press SB4 and SB8 to perform the clear operation, the method is the same as saving data.