Différences

Ci-dessous, les différences entre deux révisions de la page.

--- communication_protocole_i2c [2022/09/07 09:01] – [Exemple entre Raspberry Pi et Arduino Leonardo] serge
+++ communication_protocole_i2c [2022/09/07 09:33] (Version actuelle) – [Communication avec le protocole I2C] serge
@@ Ligne 1: / Ligne 1: @@
 ====== Communication avec le protocole I2C ======
+{{ :media_16:2_codeurs_ok.png?600 |}}
 =====Ressources=====
@@ Ligne 7: / Ligne 7: @@
   * **[[https://www.gammon.com.au/i2c|I2C par Nick Gammon]]** This post describes how the I2C (Inter-Integrated Circuit, or "Two-Wire") interface works, with particular reference to the Arduino Uno which is based on the ATmega328P microprocessor chip. A lot of the details however will be of more general interest.
   * https://github.com/nickgammon/I2C_Anything
+=====Installation sur une Pi=====
+From https://gist.github.com/ribasco/c22ab6b791e681800df47dd0a46c7c3a
+<code bash>
+sudo nano /boot/config.txt
+# Find the line containing dtparam=i2c_arm=on
+# Add i2c_arm_baudrate=<new speed> (Separate with a Comma)
+dtparam=i2c_arm=on,i2c_arm_baudrate=400000
+</code>
+Reboot Raspberry Pi\\
+Create a simple test script to verify the speed
+Switch to home directory
+  cd ~
+Create shell script
+  nano i2cspeed.sh
+Copy and paste the following lines of code
+<code bash>
+#!/bin/bash
+var="$(xxd /sys/class/i2c-adapter/i2c-1/of_node/clock-frequency | awk -F': ' '{print $2}')"
+var=${var//[[:blank:].\}]/}
+printf "%d\n" 0x$var
+</code>
+Change file permissions
+  chmod +x i2cspeed.sh
+Execute test script
+  ./i2cspeed.sh
+=====Installation sur Arduino=====
+  * https://docs.arduino.cc/learn/communication/wire
+  * https://radiostud.io/howto-i2c-communication-rpi/
+  * [[https://www.arduino.cc/reference/en/language/functions/communication/wire/|la doc arduino pour la lib Wire]]
+=====smbus2=====
+La lib I2C python
+  * https://github.com/kplindegaard/smbus2
 =====Exemple à revérifier=====
   * https://github.com/sergeLabo/furuta/tree/main/doc/NickGammon_I2C l'exemple de Nick simplifié
 =====Exemple entre Raspberry Pi et Arduino Leonardo=====
@@ Ligne 113: / Ligne 155: @@
 </code>
 =====Pull-up Resistors=====
-https://learn.sparkfun.com/tutorials/pull-up-resistors
+  * https://learn.sparkfun.com/tutorials/pull-up-resistors
+  * **[[https://www.gammon.com.au/forum/?id=10896&reply=5#reply5|Nick explique tout]]**
-{{:media_16:pull_up_resistor.png?400|}}
+On tire le signal vers le **+** avec une résistance sur SDA et SDL:
+{{ :media_16:pull_up_resistor.png?200 |}}