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W25Q FLASH Memory || Part 6 || How to Write/Read Integers, floats and 32 bit data
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Sep 2, 2023
Purchase the Products shown in this video from :: https://controllerstech.store ________________________________________________________________________________________ W25Q PART 5 :::: https://youtu.be/Mib_ASYkchg W25Q PART 7 :::: https://youtu.be/IsC_5kKcCQU W25Q STM32 Playlist :::: https://www.youtube.com/playlist?list=PLfIJKC1ud8gjUw1ExWVbeLsozbdOOigQx STM32 Playlist :::: https://www.youtube.com/playlist?list=PLfIJKC1ud8gga7xeUUJ-bRUbeChfTOOBd DOWNLOAD THIS PROJECT FROM :::: https://controllerstech.com/w25q-flash-series-part-6-integers-floats-and-32bit-data/ ________________________________________________________________________________________ ******* SUPPORT US BY DONATING****** https://paypal.me/controllertech *******Join the Membership******* https://www.youtube.com/channel/UCkdqtSMnhYuMsJkyHOxiPZQ/join
View Video Transcript
0:01
[Music]
0:08
hello and welcome to controllers Tech
0:12
this is the sixth video in The w25q
0:15
Flash series and today we will see how
0:18
to write and read floats integers and
0:21
also the 32-bit data in the previous
0:24
video we saw how to update the sectors
0:26
and how to read and write a single byte
0:29
data into the memory
0:31
we will utilize those functions in
0:33
today's video
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here is the project from the previous
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video
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we will continue editing the source file
0:41
we have created so far
0:43
a while ago I wrote a code to interface
0:46
the eeprom with stm32
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it has the code for writing the floats
0:51
and integers into the memory
0:53
actually we need to convert the numbers
0:55
into bytes first and then write the
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bytes into the memory
1:00
we use the enems to do the conversion
1:03
let's copy the conversion functions from
1:05
here and paste it in the w25q source
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file
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now let's write a function to write the
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numbers into the flash memory
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the parameters of this function are the
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start page the offset on the start page
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and the float value to right
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as I mentioned we need to convert the
1:24
floats to the byte and Float occupies
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four bytes in the memory so let's define
1:29
an array of four bytes
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inside the function we will first
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convert the float value to the bytes and
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it will be stored in the array we just
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defined
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we can write the data using the right
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byte function or using the sector update
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function the choice is yours
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I will write the code for both of them
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here so use according to your
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convenience
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the right byte function takes the
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address as the parameter so let's
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calculate the address first
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since we are writing 4 bytes of data we
2:01
need to call the right function in a for
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Loop
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the address must increment with every
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right
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writing the data using the sector update
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method is going to be easier
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comparatively
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we can pass the same parameters to the
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right function
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the size is going to be 4 bytes and the
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last parameter is the array we just
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defined
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for now I am just commenting out this
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function and we will write the data
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using the byte function
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now let's write another function to read
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the numbers
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this function will return the float
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value and the parameters are the start
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page and the offset
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since we need to read the 4 bytes for a
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single float value let's define in an
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array to store four bytes
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now we will use the read function to
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read the 4 bytes of data from the
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provided page and offset
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we have the four bytes now and we will
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use the function bytes to float to
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convert the bytes to the float value
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this value will be returned in the end
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let's define these functions in the
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header file now
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let me delete all the previous code from
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the main file
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I am going to test these functions in
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sector 0 itself so let's erase it
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let's define the float number that we
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are going to write to the memory and
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another float variable where we will
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store the value read from the memory
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when the button is pressed we will write
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the value to page 0 at an offset of 10.
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and let's also read the data from the
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same position and store it in the float
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variable we defined
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all right let's build and debug the code
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here the live expression I have added
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the float variable
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let's run the debugger now
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I am pressing the button and we have
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received the value
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this is the same as what we wrote to the
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memory
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a little variation is expected in the
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floats when they are stored
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now let's test it using the sector
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update function
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in order to write the integral value you
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can just pass the integer value to the
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function
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Let's test it now
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here you can see we have received
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exactly the same value in the live
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expression
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basically we can store any number even
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the negative values
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let's quickly test this
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here we have received the same value in
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the live expression
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so writing numbers works fine
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we can store basically any number within
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the float range
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now let's see how to store the 32-bit
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variables
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dot we will write a new function whose
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parameters will be the start page the
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offset on the start page the size of the
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data and the pointer to the 32-bit array
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we can't store the 32-bit values
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directly to the memory the memory can
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only store data in bytes
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so we need to convert the 32-bit data to
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8-bit data and hence each 32-bit
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variable will take 4 bytes
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so let's define a byte array whose size
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will be four times the size of the
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32-bit array
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Define index variable to keep track of
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the number of bytes in the byte array
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now we will split the 32-bit data and
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store it in the four different bytes of
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the data 8 buffer
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after the data has been stored we will
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write it for the memory
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we will use the right function and pass
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the parameters directly to this function
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the index variable is equal to the
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number of bytes we have stored so let's
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pass it for the size parameter
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now we will write another function to
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read the 32-bit data
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the initial definitions are going to be
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the same here
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we will first read the data bytes from
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the requested position
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the size is going to be 4 times the size
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of the 32-bit data
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now once we have the data in bytes
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format we need to convert it to the
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32-bit format
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we can do this by Shifting the data
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bytes and adding them together
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let's build the code now
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we have the Walling about the index
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variable but just ignore it
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Define these functions in the header
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file so that we can use them in the main
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file
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here we will first Define a 32-bit array
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I am storing four values which includes
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8-bit value a 16-bit value a 32-bit
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value and a random one
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Define another 32-bit array to store the
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received values
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now in the while loop when the button is
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pressed we will write the data to page 0
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at an offset of 250.
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then read the data from the same
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location and store it in the receiver
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array
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all right let's build and debug the code
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I am adding the r data array to the live
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expression
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run the debugger now
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I press the button and you can see the
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data received in the buffer let me
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change the format to hex
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you can see we have the same data that
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we wrote to the memory
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so the 32-bit variable was first
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splitted into four bytes data and it was
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then stored to the memory
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later the four bytes were read from the
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memory and then they were combined to
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Output a 32-bit data this is it for this
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video
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we were able to store and read back the
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float values the integral values and the
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32-bit variables
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I hope you understood the video
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the link to download the code is in the
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description below
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leave comments in case of any doubt
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keep watching and have a nice day ahead
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