ST3795 - Sunrom Technologies
ST3795 - Sunrom Technologies ST3795 - Sunrom Technologies
Pin Details1-VDD2-IR_TX3-RXD4-N/CST37958-GND7- N/C N/C=No Connect6- N/C5- N/CPin# Pin Name Type Notes1 VDD Supply 3 to 5V DC regulated power supply input2 IR_TX Output Connect IR LED through NPN transistor3 RXD Input Input serial UART data at 9600 bps at TTL level4-7 N/C Not Used Not Connected, This pin is not used and should be left unconnected8 GND Ground Power Supply GroundSerial Data Input FormatWhen you want to send data to chip in serial at 9600 baud rate for transmission by NEC format, youwill have to send total four bytes packet. NEC consist of 16 bit address and 8 bit data(command,keypress) information. 16 bit address of a remote is fixed while 8 bit data changes with each keypress.The packet starts from 0xCC which is start of packet identifier byte then comes address byte low,address byte high and then command byte. Once the IC receives all four byte it starts transmissionof NEC remote control code as per data received. This way you can send any type of NEC codethrough this IC.BYTE COUNT HEX Details1 0xCC Start of Packet Identifier2 0xXX Address Byte Low3 0xXX Address Byte High4 0xXX Command ByteIf you are working in C language, your microcontroller you would typically write below code totransmit a packet after you have initialize its UART to 9600 baud rate.putchar(0xCC); // Start IDputchar(0x50); // Address Lowputchar(0x31);// Address Highputchar(0x01);// Command2Sunrom Technologies Your Source for Embedded Systems Visit us at www.sunrom.com
Using PC to transmit NEC codeWhen you want to use PC to transmit a NEC code through ST3795 you can use below software totransmit a packet.To send a byte in hex format you can use $CC type declaration where the CC is a byte in hex valueto be transmited.Terminal Software http://www.sunrom.com/files/Terminal.exeWe define 4 bytepacket here in HEXvalues to betransmitted whenNEC button(M1) ispressedNote: ST3795 can be connected to PC using MAX232 to serial port or using a USB to UARTadapter.3Sunrom Technologies Your Source for Embedded Systems Visit us at www.sunrom.com
- Page 4 and 5: NEC Infrared Transmission ProtocolT
- Page 6 and 7: Dimensions DIP Package8-Lead Plasti
Pin Details1-VDD2-IR_TX3-RXD4-N/C<strong>ST3795</strong>8-GND7- N/C N/C=No Connect6- N/C5- N/CPin# Pin Name Type Notes1 VDD Supply 3 to 5V DC regulated power supply input2 IR_TX Output Connect IR LED through NPN transistor3 RXD Input Input serial UART data at 9600 bps at TTL level4-7 N/C Not Used Not Connected, This pin is not used and should be left unconnected8 GND Ground Power Supply GroundSerial Data Input FormatWhen you want to send data to chip in serial at 9600 baud rate for transmission by NEC format, youwill have to send total four bytes packet. NEC consist of 16 bit address and 8 bit data(command,keypress) information. 16 bit address of a remote is fixed while 8 bit data changes with each keypress.The packet starts from 0xCC which is start of packet identifier byte then comes address byte low,address byte high and then command byte. Once the IC receives all four byte it starts transmissionof NEC remote control code as per data received. This way you can send any type of NEC codethrough this IC.BYTE COUNT HEX Details1 0xCC Start of Packet Identifier2 0xXX Address Byte Low3 0xXX Address Byte High4 0xXX Command ByteIf you are working in C language, your microcontroller you would typically write below code totransmit a packet after you have initialize its UART to 9600 baud rate.putchar(0xCC); // Start IDputchar(0x50); // Address Lowputchar(0x31);// Address Highputchar(0x01);// Command2<strong>Sunrom</strong> <strong>Technologies</strong> Your Source for Embedded Systems Visit us at www.sunrom.com
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