Hi,
I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
Theme
Copy
r = raspi;
pc = serialdev(r,'/dev/serial0');
dataToSend = [22;4;5;6;7];
byteStream = typecast(dataToSend, 'double');
Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
Theme
Copy
function tablelook()%#codegen
r = raspi;
rsp = serialdev(r,'/dev/serial0');
output = read(rsp,5,'double');
....%my system code
write(rsp,1,'double')
(I obtain my final 0/1 through the five input parameters and output it to the serial port)
Finally,I read the data in MALTAB
Theme
Copy
read(pc,1,'double')
But I get wrong data during transmission,all of them is zeros.

Can you give me some advice?

Many thanks,
Bang

On 11/13/23 5:03 AM, Jackson Zhang wrote:
> Hi,
> I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
> Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
> Theme
> Copy
> r = raspi;
> pc = serialdev(r,'/dev/serial0');
> dataToSend = [22;4;5;6;7];
> byteStream = typecast(dataToSend, 'double');
> Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
> Theme
> Copy
> function tablelook()%#codegen
> r = raspi;
> rsp = serialdev(r,'/dev/serial0');
> output = read(rsp,5,'double');
> ...%my system code
> write(rsp,1,'double')
> (I obtain my final 0/1 through the five input parameters and output it to the serial port)
> Finally,I read the data in MALTAB
> Theme
> Copy
> read(pc,1,'double')
> But I get wrong data during transmission,all of them is zeros.
>
> Can you give me some advice?
>
> Many thanks,
> Bang
>

"Serial" can mean several things these days - from
RS-232 and friends to SPI and I2C

Sounds like you want RS-232

I'd suggest a practical tutorial like :

https://roboticsbackend.com/raspberry-pi-arduino-serial-communication/

DO remember that PIs operate at 3.3 volts and PC serial
comms are usually 5 volts - and the REAL standard is
like up to 15 volts, including NEGATIVE volts. Ergo
level-shifting hardware is required. It's cheap and not
hard to use, try AdaFruit or Seeed or SparkFun, but you
HAVE to use it.

RS-232 can be done with as few as three wires - transmit,
receive and ground. Usually, these days, you don't need
the hardware "flow control" wires. 232 CAN do a LOT of
things, but 99.9% of people rarely go beyond the simple.

Somewhere I saw an OPTICAL FIBER serial link which gets
past those voltage issues. Alas a quick look reveals
nobody selling such things of late. It would be good
for medium-length runs though ... no noise issues. If
you are fair at electronics though you could MAKE one.

On Tuesday, November 14, 2023 at 12:26:53 PM UTC+8, 56d.1152 wrote:
> On 11/13/23 5:03 AM, Jackson Zhang wrote:
> > Hi,
> > I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
> > Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
> > Theme
> > Copy
> > r = raspi;
> > pc = serialdev(r,'/dev/serial0');
> > dataToSend = [22;4;5;6;7];
> > byteStream = typecast(dataToSend, 'double');
> > Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
> > Theme
> > Copy
> > function tablelook()%#codegen
> > r = raspi;
> > rsp = serialdev(r,'/dev/serial0');
> > output = read(rsp,5,'double');
> > ...%my system code
> > write(rsp,1,'double')
> > (I obtain my final 0/1 through the five input parameters and output it to the serial port)
> > Finally,I read the data in MALTAB
> > Theme
> > Copy
> > read(pc,1,'double')
> > But I get wrong data during transmission,all of them is zeros.
> >
> > Can you give me some advice?
> >
> > Many thanks,
> > Bang
> >
> "Serial" can mean several things these days - from
> RS-232 and friends to SPI and I2C
>
> Sounds like you want RS-232
>
> I'd suggest a practical tutorial like :
>
> https://roboticsbackend.com/raspberry-pi-arduino-serial-communication/
>
> DO remember that PIs operate at 3.3 volts and PC serial
> comms are usually 5 volts - and the REAL standard is
> like up to 15 volts, including NEGATIVE volts. Ergo
> level-shifting hardware is required. It's cheap and not
> hard to use, try AdaFruit or Seeed or SparkFun, but you
> HAVE to use it.
>
> RS-232 can be done with as few as three wires - transmit,
> receive and ground. Usually, these days, you don't need
> the hardware "flow control" wires. 232 CAN do a LOT of
> things, but 99.9% of people rarely go beyond the simple.
>
> Somewhere I saw an OPTICAL FIBER serial link which gets
> past those voltage issues. Alas a quick look reveals
> nobody selling such things of late. It would be good
> for medium-length runs though ... no noise issues. If
> you are fair at electronics though you could MAKE one.

Yes you are right,I use RS-485 to connact raspberry pi and PC.And I already connect them with RXD、TXD、GND,I can detect the data of RS-485 use serial assist,but I dont know how to judge whether the raspberry pi receive the data too?

On Tuesday, November 14, 2023 at 12:26:53 PM UTC+8, 56d.1152 wrote:
> On 11/13/23 5:03 AM, Jackson Zhang wrote:
> > Hi,
> > I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
> > Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
> > Theme
> > Copy
> > r = raspi;
> > pc = serialdev(r,'/dev/serial0');
> > dataToSend = [22;4;5;6;7];
> > byteStream = typecast(dataToSend, 'double');
> > Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
> > Theme
> > Copy
> > function tablelook()%#codegen
> > r = raspi;
> > rsp = serialdev(r,'/dev/serial0');
> > output = read(rsp,5,'double');
> > ...%my system code
> > write(rsp,1,'double')
> > (I obtain my final 0/1 through the five input parameters and output it to the serial port)
> > Finally,I read the data in MALTAB
> > Theme
> > Copy
> > read(pc,1,'double')
> > But I get wrong data during transmission,all of them is zeros.
> >
> > Can you give me some advice?
> >
> > Many thanks,
> > Bang
> >
> "Serial" can mean several things these days - from
> RS-232 and friends to SPI and I2C
>
> Sounds like you want RS-232
>
> I'd suggest a practical tutorial like :
>
> https://roboticsbackend.com/raspberry-pi-arduino-serial-communication/
>
> DO remember that PIs operate at 3.3 volts and PC serial
> comms are usually 5 volts - and the REAL standard is
> like up to 15 volts, including NEGATIVE volts. Ergo
> level-shifting hardware is required. It's cheap and not
> hard to use, try AdaFruit or Seeed or SparkFun, but you
> HAVE to use it.
>
> RS-232 can be done with as few as three wires - transmit,
> receive and ground. Usually, these days, you don't need
> the hardware "flow control" wires. 232 CAN do a LOT of
> things, but 99.9% of people rarely go beyond the simple.
>
> Somewhere I saw an OPTICAL FIBER serial link which gets
> past those voltage issues. Alas a quick look reveals
> nobody selling such things of late. It would be good
> for medium-length runs though ... no noise issues. If
> you are fair at electronics though you could MAKE one.
I just want the raspberry pi run some code independently,and can send and receive data to my PC with serial ports.

On 11/14/23 2:16 AM, Jackson Zhang wrote:
> On Tuesday, November 14, 2023 at 12:26:53 PM UTC+8, 56d.1152 wrote:
>> On 11/13/23 5:03 AM, Jackson Zhang wrote:
>>> Hi,
>>> I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
>>> Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
>>> Theme
>>> Copy
>>> r = raspi;
>>> pc = serialdev(r,'/dev/serial0');
>>> dataToSend = [22;4;5;6;7];
>>> byteStream = typecast(dataToSend, 'double');
>>> Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
>>> Theme
>>> Copy
>>> function tablelook()%#codegen
>>> r = raspi;
>>> rsp = serialdev(r,'/dev/serial0');
>>> output = read(rsp,5,'double');
>>> ...%my system code
>>> write(rsp,1,'double')
>>> (I obtain my final 0/1 through the five input parameters and output it to the serial port)
>>> Finally,I read the data in MALTAB
>>> Theme
>>> Copy
>>> read(pc,1,'double')
>>> But I get wrong data during transmission,all of them is zeros.
>>>
>>> Can you give me some advice?
>>>
>>> Many thanks,
>>> Bang
>>>
>> "Serial" can mean several things these days - from
>> RS-232 and friends to SPI and I2C
>>
>> Sounds like you want RS-232
>>
>> I'd suggest a practical tutorial like :
>>
>> https://roboticsbackend.com/raspberry-pi-arduino-serial-communication/
>>
>> DO remember that PIs operate at 3.3 volts and PC serial
>> comms are usually 5 volts - and the REAL standard is
>> like up to 15 volts, including NEGATIVE volts. Ergo
>> level-shifting hardware is required. It's cheap and not
>> hard to use, try AdaFruit or Seeed or SparkFun, but you
>> HAVE to use it.
>>
>> RS-232 can be done with as few as three wires - transmit,
>> receive and ground. Usually, these days, you don't need
>> the hardware "flow control" wires. 232 CAN do a LOT of
>> things, but 99.9% of people rarely go beyond the simple.
>>
>> Somewhere I saw an OPTICAL FIBER serial link which gets
>> past those voltage issues. Alas a quick look reveals
>> nobody selling such things of late. It would be good
>> for medium-length runs though ... no noise issues. If
>> you are fair at electronics though you could MAKE one.
> I just want the raspberry pi run some code independently,and can send and receive data to my PC with serial ports.

A very simple pgm example here :

https://stackoverflow.com/questions/17539185/serial-communication-with-raspberry-pi

More complicated examples here :

https://pimylifeup.com/raspberry-pi-serial/

Bi-directional async comms are more involved, you'd
start by putting the send and receive examples above
into separate threads and 'pipe' info to the mother
program. You'd also need a pair of serial lines ...
it'd be like a "chat" server where either party can
transmit even as the other is also doing so. The good
old Send/Receive-Then-Wait model is easier.

On 11/14/2023 11:01 PM, 56d.1152 wrote:
> On 11/14/23 2:16 AM, Jackson Zhang wrote:
>> On Tuesday, November 14, 2023 at 12:26:53 PM UTC+8, 56d.1152 wrote:
>>> On 11/13/23 5:03 AM, Jackson Zhang wrote:
>>>> Hi,
>>>> I want Raspberry Pi to run a piece of code independently, read and write data from the serial port separately, and the other recipient is my PC. Can I directly deploy this code into it?I followed the Mathworks tutorial, but I don't know where the problem occurred. My current steps are as follows
>>>> Firstly, I created a connection with Raspberry Pi in MATLAB and sent a matrix
>>>> Theme
>>>> Copy
>>>> r = raspi;
>>>> pc = serialdev(r,'/dev/serial0');
>>>> dataToSend = [22;4;5;6;7];
>>>> byteStream = typecast(dataToSend, 'double');
>>>> Then,I will deploy the following code to Raspberry Pi to read data from the serial port and send some data to the serial port
>>>> Theme
>>>> Copy
>>>> function tablelook()%#codegen
>>>> r = raspi;
>>>> rsp = serialdev(r,'/dev/serial0');
>>>> output = read(rsp,5,'double');
>>>> ...%my system code
>>>> write(rsp,1,'double')
>>>> (I obtain my final 0/1 through the five input parameters and output it to the serial port)
>>>> Finally,I read the data in MALTAB
>>>> Theme
>>>> Copy
>>>> read(pc,1,'double')
>>>> But I get wrong data during transmission,all of them is zeros.
>>>>
>>>> Can you give me some advice?
>>>>
>>>> Many thanks,
>>>> Bang
>>>>
>>> "Serial" can mean several things these days - from
>>> RS-232 and friends to SPI and I2C
>>>
>>> Sounds like you want RS-232
>>>
>>> I'd suggest a practical tutorial like :
>>>
>>> https://roboticsbackend.com/raspberry-pi-arduino-serial-communication/
>>>
>>> DO remember that PIs operate at 3.3 volts and PC serial
>>> comms are usually 5 volts - and the REAL standard is
>>> like up to 15 volts, including NEGATIVE volts. Ergo
>>> level-shifting hardware is required. It's cheap and not
>>> hard to use, try AdaFruit or Seeed or SparkFun, but you
>>> HAVE to use it.
>>>
>>> RS-232 can be done with as few as three wires - transmit,
>>> receive and ground. Usually, these days, you don't need
>>> the hardware "flow control" wires. 232 CAN do a LOT of
>>> things, but 99.9% of people rarely go beyond the simple.
>>>
>>> Somewhere I saw an OPTICAL FIBER serial link which gets
>>> past those voltage issues. Alas a quick look reveals
>>> nobody selling such things of late. It would be good
>>> for medium-length runs though ... no noise issues. If
>>> you are fair at electronics though you could MAKE one.
>>    I just want the raspberry pi run some code independently,and can send and receive data to my PC with serial ports.
>
>
> A very simple pgm example here :
>
> https://stackoverflow.com/questions/17539185/serial-communication-with-raspberry-pi
>
> More complicated examples here :
>
> https://pimylifeup.com/raspberry-pi-serial/
>
> Bi-directional async comms are more involved, you'd
> start by putting the send and receive examples above
> into separate threads and 'pipe' info to the mother
> program. You'd also need a pair of serial lines ...
> it'd be like a "chat" server where either party can
> transmit even as the other is also doing so. The good
> old Send/Receive-Then-Wait model is easier.

Depending on what kind of serial link you are debugging, this is sage advice.
A comment down near the end of the article says...

https://www.abelectronics.co.uk/kb/article/1035/serial-port-setup-in-raspberry-pi-os

"You can check if the serial port works
by following our Serial Port Loopback Test <===
tutorial steps."

Tying TX to RX and "debugging your software path", is a
time honored tradition. Home experimenters have to be
a lot more inventive, when they have no test equipment.
Before you even hook up any level shifters, and start
connecting to a second device, you want to prove the local
device is working properly.

For example, if you typed "U" and a "U" did not come back,
then there would be no point hooking up any interconnect cables
to a second device, until that issue was corrected. Once your
device can talk to itself, then you can work on the harder problem
of making it talk to a peer.

Paul