Help Programming I2C LCD Component to drive HD44780 LCD Display with PCF8574AT I2C Adaptor

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
MiBe_1380881
Level 4
Level 4
10 likes received First like received

The HD44780 2x16 LCD Display with an I2C adaptor is readily available and inexpensive and would like to use this display in my Project. Can someone help me with programming of the Custom Formatting option of the I2C_LCD component to Drive the HD44780 Display with a I2C PCF8574AT adaptor. I am using 0x7E to address the adaptor. When the display is initialized it will display 3 zeros on the fist line left to right which are always on. The PrintString, ClearDisplay and Position commands do not function. The screen is not cleared and no characters a sent to the display. The I2C NXP PCF2119x LCD Display that is provided by Cypress works fine. The best I can tell, the Cypress LCD and the HD44780 have a similar Command Sets except for the setting of the display to 2 lines and 16 characters, which is 0x38 instead of 0x24 for the Cypress LCD Display. The Command Pattern for sending data  appears to be 0x00 for the HD44780 and is 0x40 for the Cypress LCD display. I have tried both 0x00 and 0x40 and neither work. Would greatly appreciate some guidance. 

   

Using the Character_LCD component is not an option for this Project.

0 Likes
6 Replies
rola_264706
Level 8
Level 8
50 likes received 25 likes received 10 likes received

Here is a program . The project explains the usage of I2C slave and I2C master components. In
*  the project when switch SW1 is pressed the I2C master writes a corresponding
*  message to the I2C slave and when switch SW2 is pressed the I2C master will
*  read back the data from the slave. Both the written and read back data are
*  displayed on LCD if both write and read operations happens successfully.

0 Likes
MiBe_1380881
Level 4
Level 4
10 likes received First like received

I can find where others have been able to interface the PSoC4 with the HD44780 using the Character_LCD component but Can the PSoC4 I2C_LCD component be used to interface with the HD44780 LCD with an I2C 8574 backpack? If so, are there any examples of how this is done? Thanks for any additional input.

0 Likes
rola_264706
Level 8
Level 8
50 likes received 25 likes received 10 likes received

That program should work.  You may have to change the address of the I2C to fit your device.

0 Likes
rola_264706
Level 8
Level 8
50 likes received 25 likes received 10 likes received

You must use the Cypress Character_LCD component so that it can use the I2C data from the I2C buffer.  I noticed that you said you couldn't use it what is the reason?

0 Likes

I am using the 28 pin - SSOP Pkg for the CY8C4245 and have used all of the free pins for my project and wanted to use the SCL and SDA pins to drive the LCD.  I am using the LCD to program the chip and then removing it after the programming has been completed. I want to minimize the number of wires needed to connect the LCD. This also simplifies the PCB layout to a smaller, one sided board which I am using in RC cars and airplanes.

   

Thanks for your reply

0 Likes
Anonymous
Not applicable

I can find where others have been able to interface the PSoC4 with the HD44780 using the Character_LCD component but Can the PSoC4 I2C_LCD component be used to interface with the HD44780 LCD with an I2C 8574 backpack. I want to minimize the number of wires needed to connect the LCD. This also simplifies the PCB layout to a smaller, one sided board which I am using in RC cars and airplanes.we are provided best laptop charger in Dubai.if you face any issue regarding Apple Laptop Charger in UAE.You may also visit our website.

0 Likes