HT66FB574 Single Colour Independent Light Streamer USB Keyboard Application Note

Transcription

1 HT66FB574 Single Colour Independent Light Streamer D/: A0490E Introduction The video gaming industry is seeing continual increasing demand for multi-feature keyboards. These can include features such as keys with an individual LED which can display different graphical effects along with variable illumination levels. With each key having an illuminated surrounding area effect along with multiple colour and pattern changes, this allows for a more colourful and stimulating gaming keyboard. Intended for the multiple-colour lighting effect product application area, Holtek has developed a series of RGB LED MCUs, the HT66FB576/574/572, which have the ability to control up to128, 64 or 40 RGB LEDs. Together with their integrated USB interface, the features combine make the devices very suitable for colourful keyboard and mouse products. This application note will introduce how to use the HT66FB574 device to develop single colour independent light streamer keyboards. Specification Description In this application note, the single colour independent light steamer USB keyboard specification is as follows. 1. USB Full Speed. 2. Mechanical key axis key rollover function. 4. High brightness single colour LED display with independent backlit key surrounding RGB LEDs. 6. Key area lighting effects: total of 9 lighting effects such as static, breathing, fade-up and so on. Supports 7-level speed adjustment and 8-level brightness adjustment. 7. Surround area lighting effects: total of 4 lighting effects which are static, breathing, streamer and neon. Supports colour switch, 7-level speed adjustment, 7-level brightness adjustment and streamer gyratory direction adjustment. 8. Supported operating systems: Windows XP, Windows Vista, Windows 7, Windows 8 and Windows 10. A0490E V / 15 June 19, 2018

2 Hardware Block Diagram HT66FB574 Single Colour Independent Light Streamer Single Colour Independent Light Streamer USB Keyboard Block Diagram Operating Principle USB 2.0 Full Speed Interface The HT66FB574 provides an USB interface function, making it suitable for general computer peripheral and consumer product applications. To communicate with an external USB host, the internal USB module has three external pins known as UDP and UD along with a 3.3V regulator output V33O. The USB interface has 8 endpoints, EP0~EP7. All endpoints except endpoint 0 can be configured with an 8, 16, 32 and 64 byte FIFO size using the UFC0~UFC2 registers. Endpoint 0 has an 8 byte FIFO size. Endpoint 0 supports control transfer, while endpoints 1~7 support interrupt or bulk transfer. The USB function control is implemented using a series of registers. A series of status registers provide the user with the USB data transfer information as well as error conditions. The USB interface contains its own independent interrupt which can be used to indicate when the USB FIFOs are accessed by the host device or with a change of the USB operating conditions including the USB suspend mode, resume event or when a USB reset occurs. Refer to the USB interface section in the corresponding datasheet for more information. A0490E V / 15 June 19, 2018

3 RGB LED PWM Driver The HT66FB574 device includes an integrated constant current source, which together with its 24 PWM output pins, has the ability to control up to 64 RGB LEDs in a matrix scan configuration. The flexible RGB LED colour change possibilities can implement breathing and lighting effects using fully internal hardware circuits. This makes the highly integrated MCU suitable for use in colour RGB products such as Gaming Keyboards, Mouse, Speakers, etc. The device reduces the need for external PWM ICs resulting in lower costs and reduced product development time. The HT66FB574 includes two LED PWM dedicated data memory sectors. The hardware can automatically calculate the PWM duty cycle according to the data written into the dedicated data memory area to implement LED colour changes and breathing effects. For more details, refer to the relevant section in the HT66FB574 Data Sheet. Refer to the PWM for RGB LED section for details on the LED PWM operations. RGB LED/ Single Colour LED Time-sharing Switch In this application note, the power to the single colour LEDs and RGB LEDs can be controlled using CMOS outputs which are generated by F/W according to the data written in the LED dedicated data memory area. By implementing the above control in a time-sharing way, the LED number can be doubled thus improving the LED application flexibility. A0490E V / 15 June 19, 2018

4 Hardware Circuit HT66FB574 Single Colour Independent Light Streamer A0490E V / 15 June 19, 2018

5 HT66FB574 Single Colour Independent Light Streamer A0490E V / 15 June 19, 2018

6 HT66FB574 Single Colour Independent Light Streamer A0490E V / 15 June 19, 2018

7 HT66FB574 Single Colour Independent Light Streamer HT66FB574 Single Colour Independent Light Streamer Keyboard Schematic Diagram A0490E V / 15 June 19, 2018

8 Key Matrix KE_C0 KE_C1 KE_C2 KE_C3 KE_C4 KE_C5 KE_C6 KE_C7 KE_R0 CTRL-L SHIFT-L CAP TAB `~ ESC KE_R1 WI-L A Q 1 F1 KE_R2 ALT_L Z S W 2 F2 KE_R3 X D E 3 F3 KE_R4 C F R 4 F4 KE_R5 V G T 5 F5 KE_R6 SPACE B H 6 F6 KE_R7 Dn_arrow ALT-R J U 7 F7 KE_R8 L_arrow Print F M K I 8 F8 KE_R9 Up_arrow SCR APP < L O 9 F9 KE_R10 R_arrow Pause CTRL-R > ; P 0 F10 KE_R11 DEL IS /? " [ - F11 KE_R12 ED HOME SHIFT_R ] = F12 KE_R13 PGD PGUP ETER \(K29) BACKSPACE Single Colour Independent Light LED Location Table SEG0 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20 SEG21 SEG22 SEG23 R0/COM0 Pause PGUP PGD SCR HOME ED Print IS DEL Up_arrow R_arrow Dn_arrow L_arrow CTRL-R R1/COM1 F12 BS \(K29) F11 ] F10 = [ ETER SHIFT_R APP " /? F R2/COM2 F9 - P F8 0 O 9 I K ; > ALT-R L < M R3/COM3 F7 8 F6 7 F5 6 U J H SPACE T G B R4/COM4 F4 5 R F3 4 E F2 3 S F V C D X ALT_L R5/COM5 F1 2 W 1 Q A ESC `~ TAB Z WI-L CAP SHIFT-L CTRL-L R6/COM6 R7/COM7 A COM6 COM6 COM6 COM6 COM6 A COM5 A COM5 COM5 Surrounding RGB LED Location Table COM5 COM5 COM4 COM4 COM4 COM4 COM4 COM3 COM3 COM3 COM2 Keyboard Obverse Side COM3 COM3 COM2 COM2 COM2 COM1 COM2 COM1 COM1 COM1 COM1 COM0 COM0 COM0 COM0 COM0 A A COM7 COM7 COM7 COM7 COM7 A A0490E V / 15 June 19, 2018

9 Program Description HT66FB574 Single Colour Independent Light Streamer The program includes a main program and an USB interrupt subroutine which is described below. Main Program Description Start Initialisation Enter Sleep? EMS Condition Sleep Wake up or not? Configured state? Key Scan and Process Lighting Effect Main Program Flowchart 1. Initialisation: Clear data memory, I/O initialisation, USB initialisation, RGB PWM Setup. 2. Determine whether the USB suspend flag has been set high: if yes, turn off the RGB PWM module and execute the HALT instruction to enter the Sleep, therefore meeting with the low power consumption requirement that the current should be less than 0.5mA. 3. If the USB suspend flag is low, program execution will continue. Otherwise go back to step After the USB is in the configured status, execute the key scan and handle procedures. 5. Implement the lighting effect dynamic display. Change the corresponding LED RAM data for the required display lighting effects to allow the hardware module to generate PWM outputs according to the LED RAM data together with I/O outputs to control the power to the RGB LEDs or single colour LEDs. A0490E V / 15 June 19, 2018

10 USB Interrupt Subroutine Description USB Interrupt Processing Endpoint 0 interrupt? Process endpoint 0 transaction Endpoint 1 interrupt? Process endpoint 1 transaction Endpoint 2 interrupt? Process endpoint 2 transaction Endpoint 3 interrupt? Process endpoint 3 transaction RETI USB Interrupt Subroutine Flowchart 1. Endpoint 0 access interrupt request flag judgment: The endpoint 0 interrupt includes SETUP, I and OUT tokens. The SETUP token is used to parse the USB commands; the I token is used to return descriptors to the host, such as a device, configuration and a report descriptor; the OUT token is used to receive report commands from the host settings, such as caps lock, num lock and scroll lock commands for host synchronising LED states. 2. Endpoint 1 access interrupt request flag judgment: There is a requirement that the bios interface reports the key data to the host in a standard 8-key format. 3. Endpoint 2 access interrupt request flag judgment: Report data to the host when certain events, such as a multimedia report data change. 4. Endpoint 3 access interrupt request flag judgment: After entering the Win system, the host can identify custom reports and implement the n-key Rollover function depending upon the key report. A0490E V / 15 June 19, 2018

11 USB EMS Condition Subroutine Description EMS Condition ESD Interference? Emulate USB insert, remove EFT Interference? Emulate USB insert, remove End Sleep Subroutine Flowchart ote: The above actions can improve the keyboard anti-interference ability. When an interference signal is detected, the software will start to emulate the USB insertion and removal actions. When the interference has ceased the enumeration will be restarted. Streamer Lighting Effect Subroutine Description Lighting Effect Streamer Effect? Change streamer effect LED RAM data Update LED RAM Data Finish Streamer effect? Change Lighting effect? RET Lighting Effect Subroutine Flowchart A0490E V / 15 June 19, 2018

12 The streamer effect is generated by updating the LED RAM data at fixed intervals to change the colour of the colour spectrum in sequence, as shown in the figure below. Streamer Effect Colour Spectrum Change Operation Description Keyboard Appearance A0490E V / 15 June 19, 2018

13 Key Area Lighting Effect Selection "F" + "IS": Cyclic switching between 9 lighting modes. The mode selected by the user is stored in the EEPROM. When subsequent power-ups occur, the selected mode will be displayed. Raindrop (Def. ) Ripple Eddy Breathing Flow Laser Pressed to out Fade-up Marquee Static "F" + " ": Speed up "F" + " ": Speed down (Total of 7 speed levels) "F" + " ": Brightness increase "F" + " ": Brightness decrease (Total 8 brightness levels) "F" + "Home": Keep pressed for about 2s to return to the default setting, the raindrop mode Surround Area Lighting Effect Selection "F" + "PgUp":Cyclic switching between 4 lighting modes. The mode selected by the user is stored in the EEPROM. When subsequent power-ups occur, the selected mode will be displayed. Breathing (Def.) Static Marquee eon "F" +"PgDn": Colour switch "F" + "-": 7-level brightness adjustment "F" + "=": 7-level speed adjustment "F" + "Scr": Direction adjustment "F" + "Home": Keep pressed for two seconds to return to the default setting, the breathing mode A0490E V / 15 June 19, 2018

14 Program Refer to the Single-colour Independent Light and Multi-colour Flow Light USB Keyboards application solution on Holtek s website for the related AP and F/W program attachments. Conclusion The HT66FB574 device includes 24 channel constant current LED PWM outputs. It has the ability to control up to 128 RGB LEDs or 192 single color LEDs + 64 RGB LEDs in a time-sharing matrix scan mode using two I/O ports together with two integrated RGB LED PWM dedicated RAM sectors. It is not a difficult task to implement a variety of single colour independent lights together with RGB LED streamer lighting effects, with reduced costs and enhanced display effects. With a USB 2.0 Full Speed interface, it provides an excellent solution for USB gaming keyboard applications which require a large amount of RGB LEDs. Version and Modify Information Date Author Issue and Revision Wang Guanzhong ( 王冠中 ) First Version Reference Files 1. HT66FB576_574_572 Data Sheet. 2. HT66FB576/574/572 RGB LED PWM Function Application Guidelines. For more information, refer to the Holtek s official website A0490E V / 15 June 19, 2018

15 Disclaimer Disclaimer All information, trademarks, logos, graphics, videos, audio clips, links and other items appearing on this website ('Information') are for reference only and is subject to change at any time without prior notice and at the discretion of Holtek Semiconductor Inc. (hereinafter 'Holtek', 'the company', 'us', 'we' or 'our'). Whilst Holtek endeavors to ensure the accuracy of the Information on this website, no express or implied warranty is given by Holtek to the accuracy of the Information. Holtek shall bear no responsibility for any incorrectness or leakage. Holtek shall not be liable for any damages (including but not limited to computer virus, system problems or data loss) whatsoever arising in using or in connection with the use of this website by any party. There may be links in this area, which allow you to visit the websites of other companies. These websites are not controlled by Holtek. Holtek will bear no responsibility and no guarantee to whatsoever Information displayed at such sites. Hyperlinks to other websites are at your own risk. Limitation of Liability In no event shall Holtek Limited be liable to any other party for any loss or damage whatsoever or howsoever caused directly or indirectly in connection with your access to or use of this website, the content thereon or any goods, materials or services. Governing Law The Disclaimer contained in the website shall be governed by and interpreted in accordance with the laws of the Republic of China. Users will submit to the non-exclusive jurisdiction of the Republic of China courts. Update of Disclaimer Holtek reserves the right to update the Disclaimer at any time with or without prior notice, all changes are effective immediately upon posting to the website. A0490E V / 15 June 19, 2018