This page (revision-10) was last changed on 2021-06-19 07:56 by Murray Altheim

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Page References

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Raspberry Pi To Arduino Over I 2 C
RaspberryPiToArduinoOverI2C

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At line 1 changed one line
This page describes experiments in communicating between a [Raspberry Pi] (as a master) and an [Arduino] (as a slave) over [I2C]. The Raspberry Pi is programmed in [Python], the Arduino using a sketch (the Arduino's own language).
This page describes experiments in communicating between a [Raspberry Pi] (as a master) and an [Arduino] (as a slave) over [I²C]. The Raspberry Pi is programmed in [Python], the Arduino using a sketch (the Arduino's own language).
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I based this experiment on an article found on ''The Robotics Back-End'' (see References below), but have modified it to use Python rather than C on the Raspberry Pi, since that's the main language I've been using to write the operating system of the [KR01] robot. Some of the ideas I found online tended to lock up the I2C bus or cause other kinds of problems. When I stumbled onto an example using the WiringPi library things seemed to even out.
I based this experiment on an article found on ''The Robotics Back-End'' (see References below), but have modified it to use Python rather than C on the Raspberry Pi, since that's the main language I've been using to write the operating system of the [KR01] robot. Some of the ideas I found online tended to lock up the I²C bus or cause other kinds of problems. When I stumbled onto an example using the WiringPi library things seemed to even out.
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[WiringPi-Python|https://github.com/WiringPi/WiringPi-Python] library.
[WiringPi-Python|https://github.com/WiringPi/WiringPi-Python] library. In particular, I tried using the {{wiringPiI2CRead()}} and {{wiringPiI2CWrite()}} methods. For documentation, see [The I²C Reference Library|http://wiringpi.com/reference/i2c-library/].
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WiringPi (both C++ and Python versions) has an I2C class to provide communication over I2C. The basic API is as follows:
{{{
class I2C(object):
def setupInterface(self,*args):
return wiringPiI2CSetupInterface(*args)
def setup(self,*args):
return wiringPiI2CSetup(*args)
def read(self,*args):
return wiringPiI2CRead(*args)
def readReg8(self,*args):
return wiringPiI2CReadReg8(*args)
def readReg16(self,*args):
return wiringPiI2CReadReg16(*args)
def write(self,*args):
return wiringPiI2CWrite(*args)
def writeReg8(self,*args):
return wiringPiI2CWriteReg8(*args)
def writeReg16(self,*args):
return wiringPiI2CWriteReg16(*args)
}}}
It should be noted that the I²C read and write methods send a single integer. In order to communicate
strings or other data, you'll need to serialise the data and then deserialise it on the other end.
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In particular, we can expect to be using the {{wiringPiI2CRead()}} and {{wiringPiI2CWrite()}} methods.
For an example, see: [How do I serialize a Python dictionary into a string, and then back to a dictionary?|https://stackoverflow.com/questions/4342176/how-do-i-serialize-a-python-dictionary-into-a-string-and-then-back-to-a-diction]
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For documentation, see [The I2C Reference Library|http://wiringpi.com/reference/i2c-library/].
In the end I developed a solution called __[pimaster2ardslave|https://github.com/ifurusato/pimaster2ardslave]__ that has been posted as a project on github, which includes a Raspberry Pi Python 3 script
and an Arduino sketch.
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I found to my consternation that the ''Arduino Nano BLE Sense'' that I bought for the purpose of being used as
the slave processor __can't be used as a slave__: the Wire library it uses hasn't implemented the I²C slave protocol, though this is not documented anywhere (I found this out on the Arduino forum). One of the benefits of the Nano BLE Sense was that it's a 3.3V device, whereas the regular Nano is 5V. I'm still searching for the right
[Arduino] board now... (😠) maybe I'll use a Teensy or an Adafruit board.
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* [Using I2C to connect two Arduino Nanos|https://sandervandevelde.wordpress.com/2015/10/13/using-i2c-to-connect-two-arduino-nanos/], blog post by Sander van de Velde
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* [Raspberry Pi (master) Arduino (slave) I2C communication with WiringPi|https://roboticsbackend.com/raspberry-pi-master-arduino-slave-i2c-communication-with-wiringpi/], from ''[The Robotics Back-End|https://roboticsbackend.com/]'' ("Program Robots Like a Boss")
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! Arduino
* [Master Reader/Slave Sender|https://www.arduino.cc/en/Tutorial/MasterReader]
* [Master Writer/Slave Receiver|https://www.arduino.cc/en/Tutorial/MasterWriter]
This page (revision-10) was last changed on 2021-06-19 07:56 by Murray AltheimTop