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everyone welcome to controllers tech
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this is another video in next in series
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and today we will see
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how to use waveforms on this display
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i will be using my stm32 for sending the
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sine wave and the square waves of
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different frequencies
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let's start by creating a new project in
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give some name to the project here
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select your display type and the display
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orientation that you want to work with
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i am going to add a waveform here
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resize it to fit the whole display
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you can change the grid width and height
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i will change it back to 40 that fits my
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you can select how many channels you
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i will use two channels to show the
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difference between the two
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let's debug this once
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i will send the waveform to this display
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that's how it's going to look
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each grid here represents 40 and that's
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why the lowest point is 40
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as i have used it as the minimum value
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let's upload it to the board
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here i am using aftdi module to upload
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the blue wire is connected between the
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display tx to the module rx
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and the yellow is between the display rx
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red is 5 volts and black is ground
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let's upload the code now
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it's uploaded and the editor part is
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let's open the cube id and create a new
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i am selecting external crystal for the
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i am using uart4 to send data to the
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change the board rate to 9600
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in the clock setup i have external eight
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and i want the system to run at maximum
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click save to generate the project
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so here is our main file
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i am adding these end commands that we
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need to send to the display
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after we are done with sending data
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now we need to send the values to the
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in order to generate the wave let's
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check the instructions for the next ian
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here we can use add function to send the
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values to the waveform
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data ranges from 0 to 255.
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here is an example to send data
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i have created a function to send the
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sine wave to this display
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don't worry i will explain this but
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first let's define the object name here
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this is the object name for the waveform
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here this function takes the parameters
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which you can see here is 1.
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then the channel number to which you
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want to send the data to
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the amplitude of the sine wave the
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the y shift and the grid height which in
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i have defined the number of samples as
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you can change them according to your
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i will explain this part later let's
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come to the main part here
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i am using the sine function to get the
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and this 127 is to keep the mean
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position of the wave in the middle of
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as we saw the values ranges here from 0
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so that's why i am using 127 to bring
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the wave to the middle
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basically 127 will be added in each
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and therefore we will get the wave in
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the middle of the display
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also the y shift will be added further
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now we send the add command with id
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number channel number
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and in the end send the end command
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let's include the math.h for sine
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and stdio for the s printf
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call the function in the while loop
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i have id number 1 channel 0 amplitude 1
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frequency 1 no y shift and the grid
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let's build and flash this
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you can see the sine wave in the middle
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this is because i haven't provided any y
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also the amplitude is 1. let's make some
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i will first change the amplitude to 2.
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you can see the wave with amplitude of
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let's increase frequency also
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this is working as expected
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i will change everything back to 1 and
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experiment with the shift in the y-axis
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that small portion is cut from the
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anyway this is working just fine
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now coming to this grid calibration here
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first we get the value of the grid width
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which in my case is 40
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but this function will get that value
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and then we get the value for the grid
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in this case this value here will be
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now i have replaced the number of
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samples with the width
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and the rest of the functions are same
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to use this part we must define this in
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now you see this part is grayed out
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let's build and flash
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you can see one oscillation of sine wave
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is equal to one width of the grid i will
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and now you can see it perfectly we can
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change the amplitude and the frequency
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that's all about the sine wave i also
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want to include the square wave here
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this is exactly the same function as the
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except for this line here this will
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basically limit the values to either
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or low no intermediate values
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let's call the square wave function also
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before that i will disable the grid
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you can use this also i just want to use
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again id number is one i want to use
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another channel for this
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and rest of the things are kept to
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this channel should be one as the first
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let's build and flash
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you can see the square wave and the sine
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wave of same frequencies
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let's try to move the square wave a
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little up on the display
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i will change the y shift to 2 here
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and we got the perfect result obviously
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one function is executing at a time and
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that's why the waves are shifting one at
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if you want both of them to shift
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simultaneously then send both the values
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and the square wave at the same time
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i will leave the code in the description
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this is it for this video in the next
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of the next ian series i will cover the
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you can download the code from the link
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keep watching be safe and have a nice
