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Interface DWIN LCM with STM32 || LED Control using Buttons
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Jun 4, 2022
Getting started with DWIN Display :: https://youtu.be/r0iMJiSr7kM DOWNLOAD THIS PROJECT FROM :::: https://controllerstech.com/wp-content/uploads/2022/05/STM32_DWIN.zip For any query and for free samples, contact ::: Lynn Guo WhatsApp/Wechat: +86 13549618767 E_mail: guomengling@dwin.com.cn/Lynn@dwin.com.cn You can also get Samples from :::: https://www.alibaba.com/product-detail/DWIN-7-Inch-Industrial-HMI-Intelligent_1600383435152.html?spm=a2747.manage.0.0.39c771d2WfHIA0 https://www.alibaba.com/product-detail/DWIN-4-3-Inch-480x272-Resolution_1600484652167.html?spm=a2747.manage.0.0.39c771d2WfHIA0 https://www.alibaba.com/product-detail/Dwin-7-inch-TFT-Display-Module_1600484719115.html?spm=a2747.manage.0.0.39c771d2WfHIA0 ________________________________________________________________________________________ ******* SUPPORT US BY DONATING****** https://paypal.me/controllertech *******Join the Membership*******
View Video Transcript
0:05
[Music]
0:14
hello and welcome to controller's tech
0:18
few days ago i covered a getting started
0:20
video on the dwin display
0:23
this is another video with the dwin hmi
0:26
display and today we will see how to
0:28
interface this display with the stm32
0:31
microcontroller
0:33
i would advise you guys to watch the
0:34
getting started video first as it will
0:37
help you understand some concepts that i
0:39
might skip in this video
0:42
the hmi displays mostly use u-arc to
0:44
communicate to the microcontrollers so
0:47
we are also going to use the u-r to
0:49
communicate with the s-d-m-32
0:52
for this demonstration i am going to
0:54
control the l-e-d on stm 32 using the
0:57
buttons on the d-win lcd
1:00
let's see the d-win website again
1:04
go to downloads tools
1:07
we have already downloaded these files
1:09
in the previous tutorial and today we
1:12
will download the serial debugging
1:14
assistant
1:15
this is needed to see the output of the
1:17
lcd whenever we are performing some
1:20
operations on it
1:22
we also need the development guide so
1:25
download this one
1:27
everything you need to know is in this
1:29
guide and i will explain the components
1:31
i am going to use as the video
1:33
progresses
1:35
all right let's start with the d gus
1:37
software
1:39
create a new project and give its
1:41
location
1:48
i have downloaded some bitmaps that i am
1:50
going to use as the on off buttons
1:54
this is going to be the background image
1:56
on the lcd
1:58
first of all we need to convert the
2:00
images to proper size and generate the
2:02
icl files for the icons and images
2:06
so let's start with the picture
2:08
conversion
2:18
this is the image we want to resize
2:22
select the screen resolution from here
2:25
now click the image conversion and save
2:28
it in the image folder inside the
2:30
project
2:34
now we will generate the icl files for
2:37
the background image and the icons
2:41
select the background image that we just
2:43
converted
2:45
click on generate icl and we must save
2:48
it in the d win set folder in our
2:49
project
2:51
but what should we name this file
2:54
to understand it we should look into the
2:56
flash memory allocation
3:01
as mentioned here the background picture
3:03
icl address is located at 32
3:08
we will also name it 32.
3:15
next we need to generate the icl file
3:17
for the icons we are using
3:20
load the icons in the icl generator and
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click generate icl
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the icl address for the icons is at 48.
3:34
so we will name the file 48.
3:37
this completes the i-c-l file
3:39
generations for the assets we are using
3:42
in this project
3:44
we also need to copy these icon files in
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the project folder
3:49
all right now we can start designing the
3:51
interface
3:59
first we will add the background image
4:02
now to display the on off icons we will
4:05
use the variable icon control
4:10
you can find more about this variable
4:13
icon in the development guide itself
4:20
as mentioned here its function is to
4:23
display different icons based on
4:25
variable value
4:27
when the variable changes the icons get
4:30
switched automatically
4:34
here is the detail of the setting page
4:36
for the variable icon
4:39
anyway i will explain these in detail
4:41
while setting them up
4:43
let's leave the sp to default we are not
4:46
covering that today
4:48
the vp stands for variable pointer and
4:51
we will see it in the end
4:53
we need to set the icon file which is 48
4:56
in our case
4:58
the variable icon takes the value from
5:00
the variable stored at the variable
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pointer
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since we are using the on and off icons
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we will keep the value of that variable
5:09
as either zero or one
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the minimum value of this variable is
5:13
going to be zero and we will set this
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green icon corresponding to this value
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similarly the maximum value is going to
5:22
be one and we will set the red icon
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corresponding to this value
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so basically when the variable is zero
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it means the led is off and the lcd is
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going to display the green icon to turn
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on the led
5:37
and when the variable is 1 the led will
5:40
be on the lcd will display the red icon
5:43
to turn off the led
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as i mentioned the variable pointer is
5:52
where the variable is going to store
5:55
this is basically a particular address
5:57
in the ram and we can think of it as the
5:59
address of some variable whose value we
6:02
can change using some means
6:05
you can find more about the variable
6:07
pointer in the development guide itself
6:10
if you notice here the ram is 128
6:14
kilobytes which ranges from 0 to fff
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with each address corresponding to 2
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bytes
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out of this the first 8 kilobytes is
6:24
reserved for the system variables and
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the user can only access the addresses
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1000 onwards
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so i am going to set the variable
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pointer address to 1100 hexa
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now the variable icon will look for the
6:39
value stored in this particular address
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and based on that value the icons will
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change automatically
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so we have set the variable pointer to
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look for the value stored at this
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particular address but we also need to
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modify the value at this particular
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address
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to do so we will use the incremental
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adjustment
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this touch control will basically
7:03
increment or decrement the value of the
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variable
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you can find more details about it in
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the development guide
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check the data auto uploading
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we will set the same variable pointer
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1100 hexa
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the adjust method is set to increment so
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each time you touch the area the value
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is going to increase
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but we want the value to be either zero
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or one so we'll set the over limit to
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cycle this will make sure that whenever
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the value has reached the maximum the
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next touch will set the value to the
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minimum
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the step length is one
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lower limit is zero and the upper limit
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is one
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so if the variable value is zero the
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touch will increment it to one and the
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next touch will reset it to zero and the
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process will continue
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this way we will achieve what we want
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the touch effect should be disposable so
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that long press will only register as a
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single click
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all right this is it for the
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configuration
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click save and generate the project
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before uploading the code to the lcd you
8:15
can debug it and check if everything is
8:18
working all right
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the icons are changing whenever we tap
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on them this means the variable is
8:24
indeed incrementing and things are
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working fine
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by the way you can also modify the
8:30
project and see the effect on the
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debugger window in real time
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so this is very helpful if you are
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designing something big
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let's upload the code to the lcd
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select the d-win set directory and it
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will automatically load the files needed
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to be flashed on the lcd
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the lcd is connected to the com11 and
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the board rate should be 11 5 200.
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click start downloading to download the
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project
9:00
all right everything is finished and you
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can see the lcd restarts with the new
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project we just copied
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the buttons are also responding well
9:13
so far everything is fine now we need to
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see what commands does this lcd send
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whenever we press these buttons
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to know this we will use the serial
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debugger we downloaded in the beginning
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make sure the com port is set to proper
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one and the baud rate is set to 11 5
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200.
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the lcd is displaying the green button
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let's press it
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you can see there is some command sent
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by the lcd over the uart
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let's understand this command first
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we need to look into the data frame
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structure
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here you can see the first data block is
10:09
the frame which is basically the 5-a a-5
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in hexadecimal
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we have also got exactly the same frame
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the next block is the data length which
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basically tells us how long the data is
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going to be
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in our case it's going to be 6 bytes
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long
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these 6 bytes contain the instruction
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the data itself and the c r c
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the next block is the instruction
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there are 2 instructions we can perform
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on the lcd
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zero cross 82 is to write something on
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the lcd and zero cross 83 is to read
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something from it
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here we are performing the read from the
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lcd
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basically when we touch the area on the
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lcd in a way we are sending the read
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instruction to the lcd and it replies
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back with the value of the variable
11:01
pointer
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after instruction we have the data
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itself which can be up to 249 bytes long
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let's see some examples to understand it
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better
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this is the example to read the variable
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pointer this here is the output from the
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lcd
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first we have the frame data length and
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the read instruction
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the next 2 bytes are the address of the
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variable pointer which in our case is
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1100
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the same what we set in the incremental
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adjustment
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after the address there is one the
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number of words to read
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we are also reading one word
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the last two bytes are the value stored
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in the ram address
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in our case the value is one
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so we press the green button and the lcd
11:56
sent one in the output and the button is
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red now
11:59
on pressing the red button everything is
12:02
the same except the value is zero
12:05
basically when the lcd displays the
12:08
green button the led will be off
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on pressing the green button the lcd
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will send one in the output which will
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turn on the led
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the lcd will display the red button now
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and on pressing it the lcd will send a
12:24
zero to the output which will turn off
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the led
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so all we have to look for is this last
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byte and whether this byte is one or
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zero will control the led
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if you count here there are a total of 9
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bytes in this command
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let's keep that in mind and now we will
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create a new project in stm32
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i am using the stm 32 f103 controller
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give some name to the project and click
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finish
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first of all we will do the clock setup
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i am choosing the external high speed
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crystal for the clock
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the blue pill has eight megahertz
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crystal and we will run the system at a
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maximum 72 megahertz frequency
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enable the serial wire debug
13:15
now we will enable the uart to
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communicate with the lcd
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i am choosing the uart 1 for this
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purpose
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make sure the board rate is set to 11 5
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200.
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leave everything to default here
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enable the interrupt as we are going to
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use interrupt to receive the data from
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the lcd
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that's all the configuration required
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click save to generate the project
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by the way i have soldered a 4-pin
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header on the lcm module the module has
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the pins tx4 tx2 rx2 and rx4
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i am connecting the tx2 to the rx pin of
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the stm32 and rx2 to the tx pin of the
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stm32 let's write the code now
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first of all we will define an array to
14:08
store 9 bytes of the data
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now in the main function we will receive
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the uart data in the interrupt mode
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we will set the interrupt to trigger
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after 9 bytes have been received
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once that happens the receive complete
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callback will be called and we will
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write the rest inside it
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if you remember the hal disables the
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interrupt after triggering it once so we
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will again call the interrupt receive
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here
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this will make sure the data is received
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continuously
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now the data is stored in the rx data
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array and if you remember only the last
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byte of this data is significant to us
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we will process this data in the while
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loop
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here we will check the last byte of this
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array and if this byte is 1 we will turn
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on the led at pc 13.
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the led on the blue pill is active low
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so to turn it on we must pull the pin
15:08
low
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similarly if the last byte is zero we
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will turn off the led by pulling it high
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i forgot to enable this pc 13 led in the
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cube mx
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set this pin to output and build the
15:23
code again
15:25
right everything is set now build the
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code and debug it
15:40
i am adding this r x data in the live
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expression
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since the lcd outputs the hexadecimal
15:46
values we need to change the format to
15:49
hexadecimal
15:50
remember that after changing it you need
15:53
to restart the debugger or else it won't
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show the correct values
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let's run the code now
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right now the green button is displaying
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on the lcd and the led is turned off
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when we press the button the led turns
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on
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you can see the rx data array the last
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byte is 1 indicating to turn on the led
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when the red button is pressed the last
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byte is zero and the led turns off
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you can see the led is responding well
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with respect to the icons on the lcd
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so i hope you understood how to
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interface this d when lcd with sdm 32
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you can interface it with any
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microcontroller which has the uart as it
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needs only you are to communicate
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this is it for the video
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i hope you understood the logic well
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enough
16:57
let me know if you want me to continue
16:59
this series in the comments below
17:02
you can download the code from the link
17:04
in the description
17:06
keep watching and have a nice day ahead
17:30
you
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