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LCD 'E' Strobe Timing Data


Effect of "too short" 'E' Strobe Pulse/Delay

P1000828rcs.JPG

P1000831rcs.JPG

Similar Effect when "tripped back" in to 8-bit/Uninitialised Mode, but receiving 4-bit data:

P1040959rcs.JPG

P1040960rcs.JPG

P1040961rcs.JPG

P1040962rcs.JPG

P1040963rcs.JPG

Summary Table

Mode

Data/Reg. Src.

E-strobe Src.

Eh_min

El_min

Code Reference

8-bit/4-bit

GPIO

GPIO

50uS

50uS

wiringPi

8-bit

PCF8574

GPIO

204uS1

41uS2

lcd_iface_8bit

4-bit

PCF8574

PCF8574

612uS3

408uS4

lcd_?i2c_4bit

4-bit

PCF8574

PCF8574

816uS5

612uS3

lcd_?i2c_4bit with -LVI2C option

8-bit

MCP23017(A)

GPIO

284uS6

41uS2

dual_lcd

4-bit

MCP23017(B)

MCP23017(B)

852uS7

41uS2

dual_lcd

8-bit

74HC595

GPIO

16uS8

41uS2

lcd_spi_8bit

4-bit

MCP23S08

MCP23S08

48uS9

41uS2

lcd_spi_4bit

4-bit

74HC595

74HC595

16uS8

41uS2

lcd_spi_4bitV2

4-bit

GPIO

GPIO

1uS10

41uS2

lcd_gpio_4bit

8-bit

74HC595

GPIO

16uS8

72uS11

glcd spi2p_8bit

LCD 'C' Structures List

(As reported by lcd_structures_list from the i2c_spi_chips-0.0 package)

lcd_iface_8bit:

(lcd_demo.c)

lcd iface_8bit status:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
RS GPIO 27
E  GPIO 22
EHMIN  204 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     3b
BSIZE   80
pcf8574 chip status:
ADDR    26
QIOP    ff
NAME    HD44780U

lcd_?i2c_4bit:

(lcd_fi2c_demo.c)

lcd fi2c_4bit status:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
EHMIN  612 uS
ELMIN  408 uS
ELMAX 1600 uS
WAIT   408 uS
NFB     28
BSIZE   80
pcf8574 chip status:
ADDR    27
QIOP    ff
NAME    HD44780U

(lcd_mi2c_demo.c)

lcd_mi2c_4bit:
lcd mi2c_4bit status:
TYPE     1
NC      16
NL       2
DDRAM[] 00 28 00 00
EHMIN  612 uS
ELMIN  408 uS
ELMAX 1600 uS
WAIT   408 uS
NFB     28
BSIZE   80
pcf8574 chip status:
ADDR    20
QIOP    ff
NAME    HD44780U

(lcd_ibo_i2c_demo.c)

lcd_ibo_i2c_4bit:
lcd ibo_i2c_4bit status:
TYPE     1
NC      16
NL       2
DDRAM[] 00 28 00 00
EHMIN  612 uS
ELMIN  408 uS
ELMAX 1600 uS
WAIT   408 uS
NFB     28
BSIZE   80
pcf8574 chip status:
ADDR    3a
QIOP    ff
NAME    HD44780U

Changes when -LVI2C option is invoked:

pi@raspiP3B16Gb:~/i2c_spi_chips-0.0 $ ./src/lcd_fi2c_demo -I -LVI2C
lcd_fi2c_demo.c Version 0.07 {Exp}, [12/07/2017], (c) F_Trevor_Gowen
                <--| Package i2c_spi_chips_0.0 |-->
<lcd_fi2c_demo.arg>     fopen: No such file or directory
lcd_fi2c_demo.arg not found
lcd fi2c_4bit status:
TYPE     1
NC      16
NL       2
DDRAM[] 00 28 00 00
EHMIN  816 uS
ELMIN  612 uS
ELMAX 1600 uS
WAIT   612 uS
NFB     28
BSIZE   80
pcf8574 chip status:
ADDR    27
QIOP    ff
NAME    fun_yellow_1602
i2cdetect -y 1

dual_lcd

(dual_lcd_i2c4-8bit_demo.c)

dual lcd status:
mcp23017 chip status:
ADDR     20
IOCON    0a
IODIRA   00
IODIRB   01
IPOLA    02
IPOLB    03
GPIOA    12
GPIOB    13
NAME     HD44780U
lcd A8bit:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
RS GPIO 22
E  GPIO 17
EHMIN  284 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     3b
BSIZE   80
lcd B4bit:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
RS GPIO 23
E  GPIO 18
EHMIN  852 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     28
BSIZE   80
B4DATA  00

lcd_spi_8bit:

(lcd_spi8b_demo.c)

lcd spi_8bit status:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
RS GPIO 22
E  GPIO 27
EHMIN   16 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     3b
BSIZE   80
gc74hc595 chip status:
SPI_DEV  /dev/spidev0.0
GOE GPIO 17
SCL GPIO 18
NAME     HD44780U

lcd_spi_4bit:

(lcd_spi4b_demo.c)

lcd spi_4bit status:
mcp23S08 chip status:
SPI_DEV /dev/spidev0.1
WADDR   40
IOCON   05
IODIR   00
IOPOL   01
GPIO    09
NAME    HD44780U
lcd S4bit:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
E  GPIO 22
EHMIN   48 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     28
BSIZE   80
S4DATA  00

lcd_spi_4bitV2:

(lcd_spi4bV2_demo.c)

lcd spi_4bitV2 status:
hw74hc595 chip status:
SPI_DEV  /dev/spidev0.0
NAME     HD44780U
lcd S4bit:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
E  GPIO 27
EHMIN   16 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     28
BSIZE   80
S4DATA  00

lcd_gpio_4bit:

(lcd_gpio4b_demo.c)

lcd gpio_4bit status:
RS  GPIO 17
E   GPIO 18
BL0 GPIO 27
BL1 GPIO 22
D4  GPIO 23
D5  GPIO 24
D6  GPIO 25
D7  GPIO 04
NAME HD44780U
lcd G4bit:
TYPE     2
NC      16
NL       2
DDRAM[] 00 28 00 00
EHMIN    1 uS
ELMIN   41 uS
ELMAX 1600 uS
WAIT    41 uS
NFB     28
BSIZE   80
G4DATA  00

glcd spi2p_8bit:

(glcd_spi8b_demo.c)

glcd spi2p_8bit status:
NC      16
NL       4
DDRAM[] 80 90 80 90
RS GPIO 25
E  GPIO 24
BL GPIO 23
EHMIN   16 uS
ELMIN   72 uS
ELMAX 1672 uS
WAIT    72 uS
gc74hc595 chip status:
SPI_DEV  /dev/spidev0.1
GOE GPIO 27
SCL GPIO 22
NAME     QC12864B/ST7920



2018-06-16 20:24