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Update README.md

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Signed-off-by: David Rotermund <54365609+davrot@users.noreply.github.com>
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@ -12,10 +12,10 @@ We want to communicate with an Arduino from Python / Matlab.
Questions to [David Rotermund](mailto:davrot@uni-bremen.de)
Get the environment ready
## Get the environment ready
Before we can really interact with the Arduino board, we need to make the environment ready first:
Download and install the Arduino IDE.
[Download](https://www.arduino.cc/en/software) and install the Arduino IDE.
Connect the Arduino via USB cable to the computer.
Open the Arduino IDE.
Open the Blink example. Files -> Examples -> 01. Basics -> Blink
@ -23,26 +23,32 @@ Check the setting: Tools-> Board and Tools->Port
Get the board information as a test: Tools -> Get Board Info
Upload the sketch (means source code)
![image0](Screenshot%202022-03-06%20163220_0.png)
The Arduino led should blink now.
If you use Python for controlling the Arduino, make sure that the serial package is installed:
```shell
pip install pyserial
WARNING: If you open a communication channel with Python / Matlab then a reset signal is created that resets the Arduino. Thus only open the communication once and keep it open as long as you require a connection to the Arduino.
```
***WARNING:*** If you open a communication channel with Python / Matlab then a reset signal is created that resets the Arduino. Thus only open the communication once and keep it open as long as you require a connection to the Arduino.
In the case that you are a VS code user, you want to add the Microsoft Arduino extension to VS code for editing the Arduino ino files in style and not like a caveperson with the Arduino IDE:
![image1](arduino_0.png)
Controlling the LED
## Controlling the LED
We want to control the LED on the Arduino board via an external software.
Note: I see it as a good style to make sure that we communicate in a fashion that reduces misunderstandings. Thus I will start any control sequence with the integer value 60 (the < symbol in ASCII) and end it with the integer value 62 (the > symbol in ASCII). The source code is prepared to handle up to 32x 8 bit integer values as payload. However we will only evaluate the value at index 0 in the switch case construct.
The Arduino sketch
```c
int rc;
boolean recvInProgress = false;
@ -107,7 +113,11 @@ void loop() {
}
}
```
Python
```python
import numpy as np
import time
import serial
@ -137,7 +147,11 @@ for t in range(0, 100):
time.sleep(time_in_sec_until_change)
print("Done")
```
Matlab
```matlab
time_in_sec_until_change = 0.5;
ser = serialport('COM3', 115200);
@ -165,10 +179,13 @@ end
fprintf("Done\n")
clear ser
```
## Pulsing the LED for a defined time
Pulsing the LED for a defined time
The Arduino sketch
```c
int rc;
boolean recvInProgress = false;
@ -246,8 +263,11 @@ void loop() {
}
}
```
Python
```python
import numpy as np
import time
import serial
@ -264,7 +284,11 @@ led_value_on: np.ndarray = np.array((start_marker, 1, stop_marker), dtype=np.uin
print("On")
ser.write(led_value_on)
```
Matlab
```matlab
ser = serialport('COM3', 115200);
% need to wait until the arduino is ready...
% I tested with 1sec and it was not enough
@ -279,24 +303,27 @@ fprintf("On\n")
write(ser,led_value_on,"uint8")
clear ser
```
## PWM control of a pin
PWM control of a pin
Warning: On an Arduino Uno LED_BUILTIN is 13. But pins that support PWM on an Uno are 3, 5, 6, 9, 10, 11 and NOT 13.
With a output value of 64:
![image2](NewFile1_0.png)
With a output value of 128:
![image3](NewFile0_0.png)
With a output value of 192:
![image4](NewFile2_0.png)
The Arduino sketch
```c
int rc;
boolean recvInProgress = false;
@ -363,7 +390,11 @@ void loop() {
}
}
```
Python
```python
import numpy as np
import time
import serial
@ -384,7 +415,11 @@ led_control: np.ndarray = np.array(
)
print("Send...")
ser.write(led_control)
```
Matlab
```matlab
ser = serialport('COM3', 115200);
% need to wait until the arduino is ready...
% I tested with 1sec and it was not enough
@ -401,8 +436,13 @@ fprintf('Send...')
write(ser,led_control,"uint8")
clear ser
Sending the internal clock
```
## Sending the internal clock
The Arduino sketch
```c
int start_marker = 60; // <
int end_marker = 62; // >
@ -429,7 +469,11 @@ void loop() {
delay(1000);
}
```
Python
```python
import time
import serial
@ -461,7 +505,10 @@ for i in range(0, read_number_of_values):
returned_value = returned_value << 8
returned_value += s[1]
print(f"Arduino-clock in ms: {returned_value}")
```
Matlab
```matlab
ser = serialport('COM3', 115200);
% need to wait until the arduino is ready...
% I tested with 1sec and it was not enough
@ -494,12 +541,16 @@ for i = [1:1:read_number_of_values],
end
end
clear ser
Sending the time on a rising interrupt
Via attachInterrupt() we attach a function to an interrupt which is triggered when a low -> high transition on a defined pin ocures. Not every pin is capable of doing so. I will use pin 2 on the Uno. Please check attachInterrupt() for list of pins.
```
## Sending the time on a rising interrupt
Via [attachInterrupt()](https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/) we attach a function to an interrupt which is triggered when a low -> high transition on a defined pin ocures. Not every pin is capable of doing so. I will use pin 2 on the Uno. Please check [attachInterrupt()](https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/) for list of pins.
The software side is the same as in the previous example.
The Arduino sketch
```c
int start_marker = 60; // <
int end_marker = 62; // >
@ -529,10 +580,13 @@ void loop() {
}
```
## Reading digital values on a rising interrupt
Reading digital values on a rising interrupt
The Arduino sketch
```c
int start_marker = 60; // <
int end_marker = 62; // >
@ -567,7 +621,10 @@ void loop() {
}
Python
```
Python:
```python
import numpy as np
import time
import serial
@ -629,8 +686,12 @@ while True:
)
if counter_samples == read_number_of_values:
break
Reading analog values on a rising interrupt
```
## Reading analog values on a rising interrupt
The Arduino sketch
```c
int start_marker = 60; // <
int end_marker = 62; // >
@ -664,10 +725,12 @@ void send_time(){
Serial.write(end_marker);
}
void loop() {
}
Python
```
Python:
```python
import numpy as np
import time
import serial
@ -731,7 +794,7 @@ while True:
)
if counter_samples == read_number_of_values:
break
```
## [Language Reference](https://www.arduino.cc/reference/en/)
@ -984,6 +1047,9 @@ while True:
|false|
### Communication
||
|---|
|[Print](https://www.arduino.cc/reference/en/language/functions/communication/print/ ) |
|[Serial]( https://www.arduino.cc/reference/en/language/functions/communication/serial/) |
|[SPI]( https://www.arduino.cc/reference/en/language/functions/communication/spi/) |
@ -992,6 +1058,8 @@ while True:
### USB
||
|---|
|[Keyboard]( https://www.arduino.cc/reference/en/language/functions/usb/keyboard/) |
|[Mouse]( https://www.arduino.cc/reference/en/language/functions/usb/mouse/) |