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HT16H25 Treadmill Display Application Guideline
D/N：AN0505E
Overview
The internal RAM of the HT16H25 is directly mapped to the corresponding LCD display
unit. It supports LCD display chips and has multiple display modes and also allows a
range of duty types to be selected. With a 1/16 Duty, it can display 960 pixels. The
internal LCD bias can be selected to be sourced from a charge pump or from a resistor
divider to drive LCD screens with an operating voltage range of 2.5V to 12V. The device
supports 4 of GPO output ports and can set the GPO output to a 64-level PWM output
mode to drive the LED backlight. Additionally, the HT16H25 supports both I
3-wire communication modes.
In this application note, the HT66F50 is used as the main control MCU which
communicates with the HT16H25 through the I
display and shows how the HT16H25 drives a 16COM × 58SEG LCD (@10V). The
application note will give the reader a clearer understanding of the HT16H25
characteristics and of its application.
Functional Description
LCD Panel Display Functions
AN0505E V1.00
HT16H25 Treadmill Display Application Guideline
LCD Panel
1 / 22
2
C interface. It simulates a treadmill LCD
January 8, 2019
2
C and SPI
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Summary of Contents for Holtek HT16H25
- Page 1 D/N：AN0505E Overview The internal RAM of the HT16H25 is directly mapped to the corresponding LCD display unit. It supports LCD display chips and has multiple display modes and also allows a range of duty types to be selected. With a 1/16 Duty, it can display 960 pixels. The internal LCD bias can be selected to be sourced from a charge pump or from a resistor divider to drive LCD screens with an operating voltage range of 2.5V to 12V.
- Page 2 HT16H25 Treadmill Display Application Guideline The diagram shows the HT16H25 Demo LCD Panel. The drive mode is 1/16 Duty, 1/5 Bias, and the working voltage is 10V. It displays some basic treadmill indicators such as calories, heart rate, speed, distance, time, etc. To implement a treadmill LCD information display, the LCD display functional description is as follows.
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Page 3: Write Operations
When SCL is high, the value of SDA must remain the same. Write Operations The HT16H25 can perform write operations such as writing a single command, writing a compound command, writing a single byte of display RAM data, writing a page of display RAM data, etc. -
Page 4: Read Operations
HT16H25 Treadmill Display Application Guideline Read Operations For a device read operation, after the host sends a START signal the slave address "0111100" + R/W bit (= "0") will be sent, after which a command byte will be sent, then an address byte and a STOP signal. - Page 5 HT16H25 Treadmill Display Application Guideline AN0505E V1.00 5 / 22 January 8, 2019...
- Page 6 HT16H25 Treadmill Display Application Guideline BS0 Bias Setting 1/5 (default) ● Driving Waveform Setting Command Command Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Def. Drive Waveform Setting Note: "DW" bit: Drive waveform setup Driving Waveform A type (default) B type ●...
- Page 7 HT16H25 Treadmill Display Application Guideline Frame Frequency (Hz) F3 F2 F1 F0 Stati 1/2 1/3 1/4 1/5 1/6 1/7 1/8 1/9 duty 50 44 50 80 67 57 50 44 40 73 67 62 57 53 50 60 53 60 96 80 69 60 53 48 87 80 74 69 64 60...
- Page 8 HT16H25 Treadmill Display Application Guideline different duty values: Max. Memory Duty Duty Data Valid Address 1/16 1/16 C0M0 ~ COM15 1/15 1/15 COM0 ~ COM14 1/14 1/14 COM0 ~ COM13 1/13 1/13 COM0 ~ COM12 1/12 1/12 COM0 ~ COM11...
- Page 9 HT16H25 Treadmill Display Application Guideline ● Read Display Data from Page 1 Command Command Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Def. Read Display Data from Page 1 － Note: This command is invalid when the duty is set to 1/9~1/16.
- Page 10 HT16H25 Treadmill Display Application Guideline ● PWM Enable Command Command Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Def. PWM Enable PEN3 PEN2 PEN1 PEN0 Note: PEN[3:0]: PWM output enable control PENn GPOn PWM Output Enable PWM output disable – GPOn output is low – default PWM output enable –...
- Page 11 HT16H25 Treadmill Display Application Guideline The Charge Pump can have the following coefficients: ×2, ×3, ×4 or ×5. Note that V is not allowed to be greater than 12V due to process limitations. Charge Pump Charge Pump Charge Pump × 3 ×...
- Page 12 HT16H25 Treadmill Display Application Guideline Note: "VS" bit: Charge Pump Input Voltage Source Select. Charge Pump Output Voltage Setup VDD (default) Internal Regulator "RE" bit: Internal Regulator On/Off Control Regulator Enable Disable (default) Enable RV[4:0]: Internal Regulator Output Voltage Select. To ensure Regulator normal operation ≥...
- Page 13 HT16H25 Treadmill Display Application Guideline LCD Bias Function Command The LCD Bias can be selected to come from the Charge Pump or from the Resistor Divider using a control command. When the LCD Bias selects the Charge Pump, the Charge Pump coefficient selection depends on the Bias setting.
- Page 14 HT16H25 Treadmill Display Application Guideline ● Bias Resistor Set Command Command Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Def. Bias Resistor Note: BR[1:0]: Bias resistor value, when the LCD bias circuit is selected as the resistor divider this instruction is effective Resistor Value 4KΩ...
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Page 15: Operating Principles
HT16H25 Treadmill Display Application Guideline Write RAM Data To write RAM data to the HT16H25, the first address of the display RAM needs to be first written, then write the display data for this corresponding address, after which enable the LCD display should be enabled. -
Page 16: Hardware Description
HT16H25 Treadmill Display Application Guideline The HT16H25 LCD Demo contains two main parts, a Top Board and a Bottom Board. The Top Board and the Bottom Board use the I C communication interface for data transmission. The Bottom Board provides DC 5V power for the Top Board. - Page 17 0R/0805 LCD Display Control Top Board The above diagram shows the HT16H25 LCD display control Top Board schematic with the LCD driver chip, the HT16H25, which has 16-COM and 8-SEG outputs to control the LCD display USB Supply Circuit...
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Page 18: Display Circuit
HT16H25 Treadmill Display Application Guideline MCU Control Circuit ICPDA PA0/C0X/AN0 PA1/TP1A/AN1 ICPCK VSS&AVSS PA2/TCK0/C0+/AN2 PB4/XT2 PA3/INT0/C0-/AN3 PB3/XT1 PA4/INT1/TCK1/AN4 PB2/OSC2 PA5/C1X/SDO/AN5 0.1uF/0805 PB1/OSC1 PA6/SDI/SDA/AN6 HT66F50 IN4148 PA7/SCK/SCL/AN7 10nF/0805 100K/0805 PB0/RES PB5/SCS/VREF 28 SOP 300R/0805 PC1/TP1B_1/SCOM1 PC2/TCK2/PCK/C1+ PC0/TP1B_0/SCOM0 PC3/PINT/TP2_0/C1- PC7/[TP1A]/SCOM3 PC4/[INT0]/[PINT]/TCK3/TP2_1 0.1uF/0805... -
Page 19: Software Description
GPO0~GPO3 can be selected to be either logic or PWM outputs to control the LCD RGB backlight. Software Description In accordance with the above application the HT16H25 LCD Demo main program flow will now be described. Main Program Flowchart START CLR_RAM();... -
Page 20: Display Description
HT16H25 Treadmill Display Application Guideline After the initialisation has completed, the program enters the main flow, clears the watchdog, and enters the display process. First, the corresponding display step is entered according to the value of the display flag bit dis_mode0, and then the LCD display RAM is updated. -
Page 21: Example Program
This application note has used the HT66F50 as the main control MCU to control the HT16H25 for a treadmill display application. It has demonstrated the main features of the HT16H25 as well as providing an application circuit and a sample program to help users use the HT16H25's functions more flexibly. -
Page 22: Limitation Of Liability
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.
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