Difference: Lecture11:The2LineLCDDisplay (4 vs. 5)

Revision 52017-11-16 - uli

Line: 1 to 1

META TOPICPARENT	name="LectureSlides"

Slide 1: The 2 Line LCD Display and its HD44780 Controller

Line: 27 to 27

Interfacing the display

Changed:

<
<

>
>

The PCF8574 I2C interface

Line: 53 to 53

Interfacing signals

Changed:

<
<

The display needs a large number of interface signals
to be able to work:

Min. 4 data lines

R/W line

back light

back light power

power

>
>

The display needs a large number of interface signals
to be able to work:

Min. 4 data lines

R/W line

back light

back light power

power

A data byte to be sent

Changed:

<
<

>
>

We will therefore need a great deal of bit fiddling

Line: 237 to 237

Interfacing to the MPU

Changed:

<
<

The HD44780 can be controlled with 8 or with 4 data bits.

In 4 bit mode (this is what we use) with the lower 4 MPU bits

>
>

The HD44780 can be controlled with 8 or with 4 data bits.

In 4 bit mode (this is what we use) with the higher 4 MPU bits

Changed:

<
<

connected to d4-d7 while the upper 4 MPU bits are used to drive.

>
>

connected to d4-d7. The hd44780 data lines d0 – d3 are disabled

Changed:

<
<

The hd44780 data lines d0 – d3 are disabled

The upper four bits are used to drive

>
>

The lower four bits are used to drive

RS (register select)
RW (read / write)
Strobe (E=enable)
and back light

Changed:

<
<

In this case the four highest significant data bits are sent first.

>
>

In this case the four highest significant data bits are sent first.

Deleted:

<
<

Instruction Summary

Line: 271 to 268

Strobe the data into the controller
Repeat the same thing for the lower significant
8 bits of the data we want to write
Keep the BL bit constant

Deleted:

<
<

Strobe function

Line: 350 to 345

META FILEATTACHMENT	attachment="initProc1.png" attr="" comment="" date="1510496819" name="initProc1.png" path="initProc1.png" size="30639" user="uli" version="1"
META FILEATTACHMENT	attachment="initProc2.png" attr="" comment="" date="1510496819" name="initProc2.png" path="initProc2.png" size="28344" user="uli" version="1"
META FILEATTACHMENT	attachment="libFunctions.png" attr="" comment="" date="1509982394" name="libFunctions.png" path="libFunctions.png" size="29147" user="uli" version="1"

Deleted:

<
<

META FILEATTACHMENT	attachment="pcf8574ifce.png" attr="" comment="" date="1510496843" name="pcf8574ifce.png" path="pcf8574ifce.png" size="65250" user="uli" version="1"

META FILEATTACHMENT	attachment="strobe.png" attr="" comment="" date="1510497029" name="strobe.png" path="strobe.png" size="69961" user="uli" version="1"
META FILEATTACHMENT	attachment="2linedisplay.png" attr="" comment="" date="1509982432" name="2linedisplay.png" path="2linedisplay.png" size="894036" user="uli" version="1"
META FILEATTACHMENT	attachment="i2c_pcf8574.png" attr="" comment="" date="1509982435" name="i2c_pcf8574.png" path="i2c_pcf8574.png" size="1038370" user="uli" version="1"

Line: 368 to 362

META FILEATTACHMENT	attachment="ddram.png" attr="" comment="" date="1510497986" name="ddram.png" path="ddram.png" size="11274" user="uli" version="1"
META FILEATTACHMENT	attachment="intfce2displ.png" attr="" comment="" date="1510498022" name="intfce2displ.png" path="intfce2displ.png" size="15238" user="uli" version="1"
META FILEATTACHMENT	attachment="writeWmd.png" attr="" comment="" date="1510498874" name="writeWmd.png" path="writeWmd.png" size="74073" user="uli" version="1"

Added:

>
>

META FILEATTACHMENT	attachment="hd44780-pcf8574circuit.png" attr="" comment="" date="1510854392" name="hd44780-pcf8574circuit.png" path="hd44780-pcf8574circuit.png" size="67950" user="uli" version="1"
META FILEATTACHMENT	attachment="hd44780_conn.png" attr="" comment="" date="1510854859" name="hd44780_conn.png" path="hd44780_conn.png" size="33368" user="uli" version="1"
META FILEATTACHMENT	attachment="lecture_11.odp" attr="" comment="" date="1510857118" name="lecture_11.odp" path="lecture_11.odp" size="2769469" user="uli" version="1"

View topic | History: r7 < r6 < r5 < r4 | More topic actions...