-->> Some custom remote control receiver <<--

Remote control receiving part of the custom at the following situations:

I.Non-self-receiver situation

If customers do not want to design a separate remote control receiver but the remote control directly to the main equipment to decode the signal, SoC system, the majority of the case, then I can offer the following solution: First, the original remote client do not have to change the decoding process, the needs of customers with our strict encoding format designed this format of the remote control code corresponding to the purpose; Another method is to provide remote control of our detailed coding specifications, the design of new customers this decoding process. Right is a set-top boxes with built-board receiver circuit of the relevant local plan, our company can provide customers a variety of chip-chip interface protocol (14SOP/18SOP/20SOP three pack).

II.UART interface customization

UART chip and the chip is suitable for short-range communication between the choice, I generally provide TTL-level compatible with the high output state idle "9600,8, n, 1" format, that is, communication rate of 9600bps, 8 data bit, 1 stop bit, without parity bit. Essentially all of the microprocessor from the grade of a simple machine, four machines, 8-bit machine to a complex 32-bit embedded processor can direct UART interface or directly to the UART format simple signal analysis and decoding than deal directly with the infrared remote control signal to the code much simpler.

UART is the most simple means of communication, in addition to customer requirements in accordance with the provision of other forms of communication protocols, such as the I2C protocol.

UART interface used to connect the two lines, one-way transmission can be, respectively, for the GND (to) and TXD (data).

III.COM (RS232) interface customization:

In line with the standard RS232 interface that is often referred to as COM port serial interface, from the sense signals RS232 and UART format is basically the same thing, the most important difference is that RS232 level must meet the RS232 specifications, standard RS232 electrical level range is-12V to +12 V, the norm that is not free when the case of data output for-12V, is for this reason that the specifications can be used RS232 data output to further afield.

In line with the standard RS232 interface that is often referred to as COM port serial interface, from the sense signals RS232 and UART format is basically the same thing, the most important difference is that RS232 level must meet the RS232 specifications, standard RS232 electrical level range is-12V to +12 V, the norm that is not free when the case of data output for-12V, is for this reason that the specifications can be used RS232 data output to further afield.

If the customer needs and the main receiver devices such as PC-to between the distances, the only way is a separate receiver power supply, as from the main equipment is the direct access to +5 V or 12V DC are also not reliable transmission more than 10 meters distance, not to mention the data from the COM port of the power line access. After a separate receiver power supply can be made the receiver the real equipment in full compliance with RS232 interface, remote control signal can be transmitted reliably from the tens. Needs to be further away from the use of standard RS485 interface, RS485 differential balanced way, there is a very good anti-interference ability, 9600BPS rate in the communications, the maximum transmission distance of 1200 meters. If the remote control using RS485 interface adapter so the side of the main equipment is also necessary to provide the RS485 interface, only the COM interface for some of the equipment such as PC machines, the most simple way is to install interface converters, directly to the RS485 signal into RS232 signal.

In addition, the infrared remote control has a feature that is taken in order to improve reliability for multi-code transmission mode, that is to say by pressing a remote control button, the vast majority will be issued until a series of key coding the same lift, This is because the infra-red face in the space to spread a variety of interfering factors, but also the direction of the remote control from the various received signal strength caused by inconsistencies in the effects of a direct impact on the receiving using code duplication the way fat is essential to improve the reliability of the . However, a dedicated remote control set up after the decoder chip, the decoded data output to the main equipment, the reliability of communication there is a very good protection, can be made for the way code, but directly by pressing a button will send a byte in order to reduce the communication complexity of the receiving process.

Keyboard to PC as an example, the keyboard has two parameters directly affect the operator's use of the habit. A response time parameter is the repeat (DELAY value), a parameter is the repeat rate (RATE). Click the General button on a code, but sometimes need to enter a string from the same site or a certain amount of adjustment for players such as the volume, then repeat after the keyboard is made of code on the necessary time for a little longer keys For example, do not open 500ms, the second the same code values will appear, this is the repeat time 500ms response time, according to a large number of tests show that at least duplicate the response time set to 250ms. Press the button does not release a long time, and the third, the fourth key will be created to appear in the number of second repeat button to repeat key rate used to show that in general is a key-per-second 10-30.

Because, taking into account the flexibility of the back-end design, in the remote control transmitter can not consider this level of response time to repeat, so as long as the button will send a string of code, a range of repetition rate of 25ms-300ms between, 100ms most about. If not specified, I am the company's products are used in ordinary serial code of the remote control button to take a way one yards. Customers can specify custom requests can be continuously made some key code, such as video conferencing systems, there are some keys to adjust the camera's aperture, Yuntai of rotation, the amount of these adjustments for the use of key code for hair treatment operate more smoothly and quickly. If a button or take a yard can be a way, the effect is, click the button raised, the equipment moves you, once again press the button, then move some equipment, and so repeatedly, the time between the two keys to have a certain intervals, must be greater than to repeat remote control codes such as the hair cycle code 100ms. Code re-issued to deal with fat is a relatively tedious work, demanding real-time, or will directly affect the use of the effect of the final product.

Some products such as mouse 4 with remote control, byte-oriented encoding, in addition to code duplication mechanism made, as well as the start byte (make code 0xa0) bytes and an end to (break code 0xaa) in order to achieve more complex control functions, such as in the realization of the mouse drag, the left button pressed, the mouse can move, the only way to achieve drag function.

Driver software: PC-in, whether it be Windows or linux, etc., the operating system itself, there is no standard remote control driver. Our solution is, on the one hand can provide the serial data format details, customers in the application program to read directly to the serial port to the corresponding remote control code can deal with; On the other hand, can my company's remote control Product development of the corresponding driver, including Windows98/me/2k/xp series, DOS series, WindowsCE and Linux Series series. Serial port that can simulate the keyboard can also simulate the mouse, you can achieve some common keyboard and mouse do not have common features, such as by a remote control button to start a specific application, according to certain rules based on a series of keys can be used for identity certification and so on.

Serial port can also create multi-user remote control buttons at the same time each time the output of the address of the remote control code and the code of the key values, see multi-user remote control of the note.

PC serial port for an external COM port of a four-wire connection, namely RTS (line through data from electricity, can also be independent to the receiver for the +5 V power), TXD (data distribution), RXD (receive data, retain or expansion) and GND (to).

IV.IrDA interface customization:

IrDA is the time for the equipment and infra-red data communications design, communication, high rate, much higher than the general control of the remote control code flow, high-speed data communications at the same time means that the design for the infrared receiver to receive from the very limited, at the same time need to prepare a dedicated driver.

IRDA is a lot of customers think that the design for the infrared remote control, this is a misunderstanding, IRDA more for high-speed infra-red data communications and design, you can see the following article:

V.PS/2 interface customization:

PS/2 interface is a PC or other similar structure of the embedded PC platform supports the standard input interface, including the PS/2 keyboard and PS/2 mouse, that is why in accordance with the PS/2 protocol designed to receive the remote control does not require any adapter the driver can direct the use of natural and nothing to do with running the operating system, of course, there are some special function key is to expand, with the motherboard and operating system are closely related, such as support for ACPI agreement Power, Sleep and Wakeup keyboard, as well as Microsoft Windows support for the expansion of the keyboard such as the media WWW, Email, Mute, etc..

PS/2 Interface Adapter Remote Control Another feature is that customers need to produce a specific code table receiver adapter. In other words, the need to specify on the remote control corresponding to each key of which ordinary PC keyboard which keys or key combinations (commonly known as the definition of shortcut keys), key features of the designated call confirmation.

PS/2 interface, including PS/2 keyboard and PS/2 mouse, if it is the remote control with mouse function keyboard or remote control, the corresponding PS/2 adapter has two PS/2 plugs were inserted into PC-PS/2 keyboard port and mouse port.

PS/2 interface uses a four-wire connection, namely VCC (power), DATA (data), CLOCK (clock) and GND (to).

VI.Custom USB interface:

USB interface adapter and remote PS/2 protocol is similar to only need to follow the USB adapter of the HID protocol design to get the support of Windows systems, the adapter is generally consistent with the USB1.1 standard, supports HID (Device Class Definition for Human Interface Devices ). Customers need to specify on the remote control corresponding to each key of which ordinary PC keyboard which keys or key combinations (commonly known as the definition of shortcut keys), key features of the designated call confirmation.

USB over PS/2 advanced is that the remote control with mouse function keyboard or remote control, the corresponding USB adapter only need a USB plug, the adapter form a complex keyboard and mouse devices.

USB interface using four-wire connection, namely VCC (power), DATA-(data -), DATA + (data +) and GND (to).

COM(RS232)	PS/2
Dual PS/2	USB

VII.Interface Specification CIR and CIR custom adapter

CIR remote control: different from the traditional COM, PS/2 or USB standard interface, and the need to consider the remote control transmitter, CIR module and the corresponding operating system applications.

CIR (Consumer Infrared)

VIA EPIA motherboard CIR provides an interface very similar to PS/2 interface, the pin generally IDC5x2 form.

In view of this CIR interface that CIR adapter specially designed collection of different types of remote control models (as required by the customer to design, production), EPIA into the host to identify the signal. The device in the digital entertainment set-top boxes and PC-type devices widely used. I, as a third-party equipment suppliers VIA can provide CIR-related technology and products, both designed and manufactured adapter CIR can also be designed and manufactured, including a remote control transmitter, remote control keyboard, mouse, such as remote control, they can even provide the corresponding low-level software development, sales of such products only to the equipment manufacturers, systems integrators, end users do not provide for such products.

Production of such products, customers need to give full consideration to the size of the motherboard and chassis structure, taking into account possible future changes in machine design.

Right is a practical example of the ML with the VIA EPIA series motherboard design, specially designed 22-point infra-red sensor, a board to front board installed in the form of the machine on the front panel, one is external through 1.5 m long wire leads, at the desktop. For example, the hotel set-top box terminals, and some hotels will be set-top box terminal at the desktop, this time can use the built-in receiver board; Some hotels will be placed under the table set-top box terminals, built-in receiver board it will be difficult to play a role, At this time the receiver can be placed in an external desktop.