Use LS7232 to make high-end infrared remote control dimmer lights

The high-end infrared remote control dimmer lamp consists of two parts: an infrared remote control transmitter and a receiver. Figure 2-18 is an infrared remote control receiver
, which assembles all the infrared receiver, decoding and touch dimming circuits into a standard wall switch box.
When used, it can be used for dimming or switching operations using manual touch. , you can also use the 8-button infrared remote control transmitter shown in Figure 2-17 for
long-distance remote control operation. Moreover, this remote control transmitter can control up to 6 dimmer switch boxes and 2
light switches respectively as shown in Figure 2-18, without interfering with each other during operation, which is very convenient. The
    infrared remote control transmitter uses the BA5104 special coding integrated circuit. Its pins 1 and 2 are user code selection terminals. They can be grounded or suspended
separately or completely, but it requires l 1 and 12 of the matching BA5204 decoding integrated circuit in the receiver. The pins
should also be left floating or grounded accordingly. The purpose of setting the user code is to prevent other people’s remote controls from controlling the dimming lights in your home
unless the user codes of the two homes are the same.
    Pins 3 to 11 (except pin 8) of the BA5104 integrated block are connected to 8 control buttons. Pressing each button
can change the level of the corresponding pin of BA5204 in the receiver. The corresponding relationship is shown in Table 2.7. . LED1 is the emission indicator light.
LED2 is an infrared emitting diode. Press any button from SBJ to SB8, LED2 will emit modulated infrared
light. The transmission frequency is controlled by the crystal oscillator between pins 12 and 13.
    The receiving module BA5204 is used in conjunction with the BA5104. Its working voltage is 5v, which is supplied by VD1 as a regulated voltage. Its
pin 13 is the internal oscillator timing terminal, and is externally connected to R4 and CI resistor-capacitor network. Pins 3~10 are control output terminals. It can
be seen from Table 2-7 that its 6 ports of pins 3-8 are non-holding terminals. That is, when BA5104 presses any button among SB1-SB6,
the corresponding pin of BA5204 One port outputs a high level. When the transmitter releases the button, the port returns to a low level.
The time it maintains the high level is the same as the time the button is held down. This device uses this non-holding function to realize remote control dimming. As can
be seen from the figure, only pin 8 is used in the receiver, and other ports are left floating and connected. As shown in Table 2-7, the corresponding transmitter
The receiver needs to press the button SB6 to control this receiver. The other SBI~SB5 can control the other 5 remote control dimmer lights (the other 5
remote control receivers only need to connect the resistor R6 to the corresponding pin port). Pin 9 and pin 10 are hold function ports, that is,
when the power is first turned on, these two ports output low level. If the transmitter presses SB7 or SB8, the corresponding pin 9 or 10 will output
high level . If the transmitter is loosened, When the button is turned on, the high level remains unchanged. If the same button on the transmitter is pressed again, the port
switches back to low level. Using the hold function port , you can control turning on and off lights or other household appliances.
    Al is an integrated integrated circuit for infrared reception and demodulation. It can restore the infrared signal emitted by the transmitter into a coded
negative pulse train that can be read by the decoding integrated circuit, that is, the pulse head is facing down. However, BA5204 requires positive polarity pulse input, so the circuit
uses the transistor VTI to invert and amplify and then sends it to pin 2 of BA5204. The output signal of pin 8 is level
converted and sent to pin 6 of the dimming integrated circuit LS7232. Use your feet to remotely control dimming and switch lights. M is the touch electrode piece on the switch box
, and the light can be dimmed and turned on and off by touching M with your hand. That is, if the time of pressing the button (or the time of touching M) is greater than 0.4s,
it is in the dimming state. When the button is released (or the finger leaves M),
the light brightness is fixed. The next time the light is turned off, the light brightness can be adjusted. Be remembered. The time of pressing the button (or the time of touching M) is less than 0.4s. It is a light switch operation.