Sending Serial Data to Arduino Using Python Script
I am facing a peculiar issue while writing characters to Arduino using python serial communication on macOS 10.14.
The Arduino is programmed to read a string, parse it and take PWM action to run a car.
Ardiuno's serial communication channel is configured to receive the strings in the format < A, B, C, D > where ABCD are numbers which denote car direction, speed, steering direction and steering position.
The problem is, when I send a string from the serial monitor or through the Python Development environment the string is received, parsed properly and command executed successfully.
However if I write a simple program in a file write.py and execute it from the command line, nothing happens.
import serial
ser = serial.Serial('/dev/cu.usbmodem14301', 9600)
data = '<1,150,0,0>'
ser.write(data.encode())
If I run this script from the macOS terminal using the command:
python write.py
nothing happens. What am I missing here?
python-3.x arduino pyserial
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
add a comment |
I am facing a peculiar issue while writing characters to Arduino using python serial communication on macOS 10.14.
The Arduino is programmed to read a string, parse it and take PWM action to run a car.
Ardiuno's serial communication channel is configured to receive the strings in the format < A, B, C, D > where ABCD are numbers which denote car direction, speed, steering direction and steering position.
The problem is, when I send a string from the serial monitor or through the Python Development environment the string is received, parsed properly and command executed successfully.
However if I write a simple program in a file write.py and execute it from the command line, nothing happens.
import serial
ser = serial.Serial('/dev/cu.usbmodem14301', 9600)
data = '<1,150,0,0>'
ser.write(data.encode())
If I run this script from the macOS terminal using the command:
python write.py
nothing happens. What am I missing here?
python-3.x arduino pyserial
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
1
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14
add a comment |
I am facing a peculiar issue while writing characters to Arduino using python serial communication on macOS 10.14.
The Arduino is programmed to read a string, parse it and take PWM action to run a car.
Ardiuno's serial communication channel is configured to receive the strings in the format < A, B, C, D > where ABCD are numbers which denote car direction, speed, steering direction and steering position.
The problem is, when I send a string from the serial monitor or through the Python Development environment the string is received, parsed properly and command executed successfully.
However if I write a simple program in a file write.py and execute it from the command line, nothing happens.
import serial
ser = serial.Serial('/dev/cu.usbmodem14301', 9600)
data = '<1,150,0,0>'
ser.write(data.encode())
If I run this script from the macOS terminal using the command:
python write.py
nothing happens. What am I missing here?
python-3.x arduino pyserial
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
I am facing a peculiar issue while writing characters to Arduino using python serial communication on macOS 10.14.
The Arduino is programmed to read a string, parse it and take PWM action to run a car.
Ardiuno's serial communication channel is configured to receive the strings in the format < A, B, C, D > where ABCD are numbers which denote car direction, speed, steering direction and steering position.
The problem is, when I send a string from the serial monitor or through the Python Development environment the string is received, parsed properly and command executed successfully.
However if I write a simple program in a file write.py and execute it from the command line, nothing happens.
import serial
ser = serial.Serial('/dev/cu.usbmodem14301', 9600)
data = '<1,150,0,0>'
ser.write(data.encode())
If I run this script from the macOS terminal using the command:
python write.py
nothing happens. What am I missing here?
python-3.x arduino pyserial
python-3.x arduino pyserial
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
edited Nov 12 '18 at 16:08
Paul Roub
32.6k85773
32.6k85773
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
asked Nov 12 '18 at 11:05
Yashwant SinghYashwant Singh
31
31
1
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14
add a comment |
1
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14
1
1
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14
add a comment |
3 Answers
3
active
oldest
votes
A new USB connection with ser=serial.Serial('/dev/cu.usbmodem14301',9600) resets the Arduino. The data sent right after connection are lost because the Arduino boots.
answered Nov 12 '18 at 12:22
JurajJuraj
344310
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
add a comment |
It may be that the port is in text mode and will not send the data until a newline is sent:
data = '<1,150,0,0>n'
ser.write(data.encode())
or flush() is called.
data = '<1,150,0,0>'
ser.write(data.encode())
ser.flush()
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
add a comment |
The most probably thing happening here is that the data is not being sent to the serial port.
There is a simple method to check this.
Connect the Arduino to your laptop (I suspect it to be a mac), and start the serial monitor on the Arduino IDE.
In the serial monitor type in <1,150,0,0> and press send.
The tx LED on the Arduino will blink. Now that you know how the pattern looks, repeat the same experiment with the Python code.
If the LED does not blink in the same manner you have a Serial port access issue, which you can fix using the instructions in the following link
Access USB serial ports using Python and pyserial
If not, I am stumped.
answered Nov 12 '18 at 11:39
NitroNitro
666213
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53260841%2fsending-serial-data-to-arduino-using-python-script%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
A new USB connection with ser=serial.Serial('/dev/cu.usbmodem14301',9600) resets the Arduino. The data sent right after connection are lost because the Arduino boots.
answered Nov 12 '18 at 12:22
JurajJuraj
344310
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
add a comment |
A new USB connection with ser=serial.Serial('/dev/cu.usbmodem14301',9600) resets the Arduino. The data sent right after connection are lost because the Arduino boots.
answered Nov 12 '18 at 12:22
JurajJuraj
344310
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
add a comment |
A new USB connection with ser=serial.Serial('/dev/cu.usbmodem14301',9600) resets the Arduino. The data sent right after connection are lost because the Arduino boots.
answered Nov 12 '18 at 12:22
JurajJuraj
344310
A new USB connection with ser=serial.Serial('/dev/cu.usbmodem14301',9600) resets the Arduino. The data sent right after connection are lost because the Arduino boots.
answered Nov 12 '18 at 12:22
JurajJuraj
344310
answered Nov 12 '18 at 12:22
JurajJuraj
344310
answered Nov 12 '18 at 12:22
JurajJuraj
344310
answered Nov 12 '18 at 12:22
JurajJuraj
344310
344310
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
add a comment |
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
This works. I was establishing the serial connection within the function so every time i was writing to Arduino a new connection was getting established, moving the connection declaration out function scope solved the problem.
– Yashwant Singh
Nov 12 '18 at 17:13
add a comment |
It may be that the port is in text mode and will not send the data until a newline is sent:
data = '<1,150,0,0>n'
ser.write(data.encode())
or flush() is called.
data = '<1,150,0,0>'
ser.write(data.encode())
ser.flush()
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
add a comment |
It may be that the port is in text mode and will not send the data until a newline is sent:
data = '<1,150,0,0>n'
ser.write(data.encode())
or flush() is called.
data = '<1,150,0,0>'
ser.write(data.encode())
ser.flush()
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
add a comment |
It may be that the port is in text mode and will not send the data until a newline is sent:
data = '<1,150,0,0>n'
ser.write(data.encode())
or flush() is called.
data = '<1,150,0,0>'
ser.write(data.encode())
ser.flush()
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
It may be that the port is in text mode and will not send the data until a newline is sent:
data = '<1,150,0,0>n'
ser.write(data.encode())
or flush() is called.
data = '<1,150,0,0>'
ser.write(data.encode())
ser.flush()
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
answered Nov 12 '18 at 11:16
Roger IrwinRoger Irwin
175
175
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
add a comment |
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
I have used a sketch shared in Arduino forum which has start marker and end marker configurable, newline should be applicable when i send serial write using Python Shell, it works perfectly when using serial monitor in Arduino IDE or Python shell. Will try adding flush in the code and see if that works.
– Yashwant Singh
Nov 12 '18 at 11:26
add a comment |
The most probably thing happening here is that the data is not being sent to the serial port.
There is a simple method to check this.
Connect the Arduino to your laptop (I suspect it to be a mac), and start the serial monitor on the Arduino IDE.
In the serial monitor type in <1,150,0,0> and press send.
The tx LED on the Arduino will blink. Now that you know how the pattern looks, repeat the same experiment with the Python code.
If the LED does not blink in the same manner you have a Serial port access issue, which you can fix using the instructions in the following link
Access USB serial ports using Python and pyserial
If not, I am stumped.
answered Nov 12 '18 at 11:39
NitroNitro
666213
add a comment |
The most probably thing happening here is that the data is not being sent to the serial port.
There is a simple method to check this.
Connect the Arduino to your laptop (I suspect it to be a mac), and start the serial monitor on the Arduino IDE.
In the serial monitor type in <1,150,0,0> and press send.
The tx LED on the Arduino will blink. Now that you know how the pattern looks, repeat the same experiment with the Python code.
If the LED does not blink in the same manner you have a Serial port access issue, which you can fix using the instructions in the following link
Access USB serial ports using Python and pyserial
If not, I am stumped.
answered Nov 12 '18 at 11:39
NitroNitro
666213
add a comment |
The most probably thing happening here is that the data is not being sent to the serial port.
There is a simple method to check this.
Connect the Arduino to your laptop (I suspect it to be a mac), and start the serial monitor on the Arduino IDE.
In the serial monitor type in <1,150,0,0> and press send.
The tx LED on the Arduino will blink. Now that you know how the pattern looks, repeat the same experiment with the Python code.
If the LED does not blink in the same manner you have a Serial port access issue, which you can fix using the instructions in the following link
Access USB serial ports using Python and pyserial
If not, I am stumped.
answered Nov 12 '18 at 11:39
NitroNitro
666213
The most probably thing happening here is that the data is not being sent to the serial port.
There is a simple method to check this.
Connect the Arduino to your laptop (I suspect it to be a mac), and start the serial monitor on the Arduino IDE.
In the serial monitor type in <1,150,0,0> and press send.
The tx LED on the Arduino will blink. Now that you know how the pattern looks, repeat the same experiment with the Python code.
If the LED does not blink in the same manner you have a Serial port access issue, which you can fix using the instructions in the following link
Access USB serial ports using Python and pyserial
If not, I am stumped.
answered Nov 12 '18 at 11:39
NitroNitro
666213
answered Nov 12 '18 at 11:39
NitroNitro
666213
answered Nov 12 '18 at 11:39
NitroNitro
666213
answered Nov 12 '18 at 11:39
NitroNitro
666213
666213
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53260841%2fsending-serial-data-to-arduino-using-python-script%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
1
Possible duplicate of Serial communication between Arduino and Matlab is losing data
– gre_gor
Nov 13 '18 at 0:14