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2022/1/9
初版

MAKER_PI_RP2040_I2C

MAKER_PI_RP2040_I2C

概要

MAKER_PI_RP2040でI2Cを使う。
MAKER_PI_RP2040「MAKER_PI_RP2040」はCircuitPythonがプリインストールされている。Arduinoとして使用する際、通常wire,wire1の2つが使用できるが本ボードでは複数のI2Cが使用可能なgroveソケットを持っているので、どれを使用したら良いかが不明である。
そこでArduino-IDEとしてはpico公式版ではなく非公式earlephilhower/arduino picoでを使用する。この版は、I2Cのピンの割当関数があるので、それを使って使用するピンを指定できる。

留意点:
/dev/ttyACM0が見えている場合、USB-Serial経由の制御で自動的に書き込みモードになるので、特に操作はいらない。/dev/ttyACM0が見えていないときは、自動での書き込みモードができないので、手動で、[BOOT],[RST]ボタンを使って書き込みモードにすること。

I2C_Scanner

まずは、以下のスケッチで、I2Cの動作確認と接続しているI2Cデバイスのアドレスを確認する。
GROVE#4にI2Cデバイス(またはI2C-HUB経由)を接続する。

Arduino公式サイトにあったものにピン割当を追加しただけだが、以下にそのまま掲げる:
I2C_Scanner.ino


// --------------------------------------
// i2c_scanner
//
// Version 1
//    This program (or code that looks like it)
//    can be found in many places.
//    For example on the Arduino.cc forum.
//    The original author is not know.
// Version 2, Juni 2012, Using Arduino 1.0.1
//     Adapted to be as simple as possible by Arduino.cc user Krodal
// Version 3, Feb 26  2013
//    V3 by louarnold
// Version 4, March 3, 2013, Using Arduino 1.0.3
//    by Arduino.cc user Krodal.
//    Changes by louarnold removed.
//    Scanning addresses changed from 0...127 to 1...119,
//    according to the i2c scanner by Nick Gammon
//    https://www.gammon.com.au/forum/?id=10896
// Version 5, March 28, 2013
//    As version 4, but address scans now to 127.
//    A sensor seems to use address 120.
// Version 6, November 27, 2015.
//    Added waiting for the Leonardo serial communication.
// 
//
// This sketch tests the standard 7-bit addresses
// Devices with higher bit address might not be seen properly.
//

#include <Wire.h>


void setup()
{
  // GROVE#4 for I2C#0
  Wire.setSDA(16);
  Wire.setSCL(17);
  //Wire.begin();

  Wire.begin();

  Serial.begin(9600);
  while (!Serial);             // Leonardo: wait for serial monitor
  Serial.println("\nI2C Scanner");
}


void loop()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ ) 
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4) 
    {
      Serial.print("Unknown error at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);           // wait 5 seconds for next scan
}

シリアル出力例:


I2C Scanner
Scanning...
I2C device found at address 0x3D  !
I2C device found at address 0x76  !
done

Scanning...
I2C device found at address 0x3D  !
I2C device found at address 0x76  !
done

BMP280のスケッチ

M5Stack用の「M5Stack用大気圧センサーユニット【M5STACK-U090】」をGROVE#4に接続して使用する。
本ユニットはBMP280を使用しており、BMP280のAdafruitのライブラリが使用できる。 以下は提供されているサンプルにピン割当、デバイスアドレスの変更をしたものである。

bmp280_sensortest_MAKER.ino



/***************************************************************************
  This is a library for the BMP280 humidity, temperature & pressure sensor
  This example shows how to take Sensor Events instead of direct readings
  
  Designed specifically to work with the Adafruit BMP280 Breakout
  ----> http://www.adafruit.com/products/2651

  These sensors use I2C or SPI to communicate, 2 or 4 pins are required
  to interface.

  Adafruit invests time and resources providing this open source code,
  please support Adafruit and open-source hardware by purchasing products
  from Adafruit!

  Written by Limor Fried & Kevin Townsend for Adafruit Industries.
  BSD license, all text above must be included in any redistribution
 ***************************************************************************/

#include <Wire.h>
#include <SPI.h>
#include <Adafruit_BMP280.h>

Adafruit_BMP280 bmp; // use I2C interface
Adafruit_Sensor *bmp_temp = bmp.getTemperatureSensor();
Adafruit_Sensor *bmp_pressure = bmp.getPressureSensor();

void setup() {
  Serial.begin(9600);
  while ( !Serial ) delay(100);   // wait for native usb
  Serial.println(F("BMP280 Sensor event test"));

  // GROVE#4 for I2C#0
  Wire.setSDA(16);
  Wire.setSCL(17);
  Wire.begin();

  unsigned status;
  //status = bmp.begin(BMP280_ADDRESS_ALT, BMP280_CHIPID);
  status = bmp.begin(0x76); // for BPS UNIT of M5Stack
  if (!status) {
    Serial.println(F("Could not find a valid BMP280 sensor, check wiring or "
                      "try a different address!"));
    Serial.print("SensorID was: 0x"); Serial.println(bmp.sensorID(),16);
    Serial.print("        ID of 0xFF probably means a bad address, a BMP 180 or BMP 085\n");
    Serial.print("   ID of 0x56-0x58 represents a BMP 280,\n");
    Serial.print("        ID of 0x60 represents a BME 280.\n");
    Serial.print("        ID of 0x61 represents a BME 680.\n");
    while (1) delay(10);
  }

  /* Default settings from datasheet. */
  bmp.setSampling(Adafruit_BMP280::MODE_NORMAL,     /* Operating Mode. */
                  Adafruit_BMP280::SAMPLING_X2,     /* Temp. oversampling */
                  Adafruit_BMP280::SAMPLING_X16,    /* Pressure oversampling */
                  Adafruit_BMP280::FILTER_X16,      /* Filtering. */
                  Adafruit_BMP280::STANDBY_MS_500); /* Standby time. */

  bmp_temp->printSensorDetails();
}

void loop() {
  sensors_event_t temp_event, pressure_event;
  bmp_temp->getEvent(&temp_event);
  bmp_pressure->getEvent(&pressure_event);
  
  Serial.print(F("Temperature = "));
  Serial.print(temp_event.temperature);
  Serial.println(" *C");

  Serial.print(F("Pressure = "));
  Serial.print(pressure_event.pressure);
  Serial.println(" hPa");

  Serial.println();
  delay(2000);
}

シリアル出力例:


BMP280 Sensor event test
------------------------------------
Sensor:       BMP280
Type:         Ambient Temp (C)
Driver Ver:   1
Unique ID:    280
Min Value:    -40.00
Max Value:    85.00
Resolution:   0.01
------------------------------------

Temperature = 19.14 *C
Pressure = 1012.88 hPa

Temperature = 19.15 *C
Pressure = 1012.81 hPa

Temperature = 19.15 *C
Pressure = 1012.83 hPa

Qwiic_OLEDのスケッチ

Qwiic - 小型OLEDモジュールをQwiic->Grove変換ケーブル経由でGROVE#4に接続する。
(なぜかピン割当を追加せず)提供されたスケッチがそのまま動作したが以下に挙げる:
(ちなみに正式版Arduinoでは動作しなかった)

Example10_MultiDemo_v13.ino


/*
  SFE_MicroOLED Library Demo
  Paul Clark @ SparkFun Electronics
  Original Creation Date: December 11th, 2020

  This sketch uses the MicroOLED library to show all the functionality built into the library
  using the begin function defined in version v1.3 of the library - which allows different
  TwoWire ports and custom I2C addresses to be used.

  If you are using the standard Micro OLED display, its I2C address will be 0x3D or 0x3C
  depending on how you have the D/C or ADDR jumper configured.

  Hardware Connections:
    This example assumes you are using Qwiic. See the SPI examples for
    a detailed breakdown of connection info.

  Want to support open source hardware? Buy a board from SparkFun!
  https://www.sparkfun.com/products/13003
  https://www.sparkfun.com/products/14532

  This code is beerware; if you see me (or any other SparkFun employee) at the
  local, and you've found our code helpful, please buy us a round!
  
  Distributed as-is; no warranty is given.
*/

#include <Wire.h>
#include <SFE_MicroOLED.h> //Click here to get the library: http://librarymanager/All#SparkFun_Micro_OLED

#define PIN_RESET 9

/*
// This is the old way of instantiating oled. You can still do it this way if you want to.
#define DC_JUMPER 1
MicroOLED oled(PIN_RESET, DC_JUMPER); // I2C declaration
*/

// From version v1.3, we can also instantiate oled like this (but only for I2C)
MicroOLED oled(PIN_RESET); // The TwoWire I2C port is passed to .begin instead

void setup()
{
  delay(100);
  Wire.begin(); // <-- Change this to (e.g.) Qwiic.begin(); as required
  //Wire.setClock(400000); // Uncomment this line to increase the I2C bus speed to 400kHz


/*
  // This is the old way of initializing the OLED.
  // You can still do it this way if you want to - but only
  // if you instantiated oled using: MicroOLED oled(PIN_RESET, DC_JUMPER)
  oled.begin();    // Initialize the OLED
*/


  // This is the new way of initializing the OLED.
  // We can pass a different I2C address and TwoWire port
  oled.begin(0x3D, Wire);    // Initialize the OLED


/*
  // This is the new way of initializing the OLED.
  // We can pass a different I2C address and TwoWire port
  oled.begin(0x3C, Qwiic);    // Initialize the OLED
*/


  oled.clear(ALL); // Clear the display's internal memory
  oled.display();  // Display what's in the buffer (splashscreen)

  delay(1000); // Delay 1000 ms

  oled.clear(PAGE); // Clear the buffer.

  randomSeed(analogRead(A0) + analogRead(A1));
}

void pixelExample()
{
  printTitle("Pixels", 1);

  for (int i = 0; i < 512; i++)
  {
    oled.pixel(random(oled.getLCDWidth()), random(oled.getLCDHeight()));
    oled.display();
  }
}

void lineExample()
{
  int middleX = oled.getLCDWidth() / 2;
  int middleY = oled.getLCDHeight() / 2;
  int xEnd, yEnd;
  int lineWidth = min(middleX, middleY);

  printTitle("Lines!", 1);

  for (int i = 0; i < 3; i++)
  {
    for (int deg = 0; deg < 360; deg += 15)
    {
      xEnd = lineWidth * cos(deg * PI / 180.0);
      yEnd = lineWidth * sin(deg * PI / 180.0);

      oled.line(middleX, middleY, middleX + xEnd, middleY + yEnd);
      oled.display();
      delay(10);
    }
    for (int deg = 0; deg < 360; deg += 15)
    {
      xEnd = lineWidth * cos(deg * PI / 180.0);
      yEnd = lineWidth * sin(deg * PI / 180.0);

      oled.line(middleX, middleY, middleX + xEnd, middleY + yEnd, BLACK, NORM);
      oled.display();
      delay(10);
    }
  }
}

void shapeExample()
{
  printTitle("Shapes!", 0);

  // Silly pong demo. It takes a lot of work to fake pong...
  int paddleW = 3;  // Paddle width
  int paddleH = 15; // Paddle height
  // Paddle 0 (left) position coordinates
  int paddle0_Y = (oled.getLCDHeight() / 2) - (paddleH / 2);
  int paddle0_X = 2;
  // Paddle 1 (right) position coordinates
  int paddle1_Y = (oled.getLCDHeight() / 2) - (paddleH / 2);
  int paddle1_X = oled.getLCDWidth() - 3 - paddleW;
  int ball_rad = 2; // Ball radius
  // Ball position coordinates
  int ball_X = paddle0_X + paddleW + ball_rad;
  int ball_Y = random(1 + ball_rad, oled.getLCDHeight() - ball_rad); //paddle0_Y + ball_rad;
  int ballVelocityX = 1;                                             // Ball left/right velocity
  int ballVelocityY = 1;                                             // Ball up/down velocity
  int paddle0Velocity = -1;                                          // Paddle 0 velocity
  int paddle1Velocity = 1;                                           // Paddle 1 velocity

  //while(ball_X >= paddle0_X + paddleW - 1)
  while ((ball_X - ball_rad > 1) &&
         (ball_X + ball_rad < oled.getLCDWidth() - 2))
  {
    // Increment ball's position
    ball_X += ballVelocityX;
    ball_Y += ballVelocityY;
    // Check if the ball is colliding with the left paddle
    if (ball_X - ball_rad < paddle0_X + paddleW)
    {
      // Check if ball is within paddle's height
      if ((ball_Y > paddle0_Y) && (ball_Y < paddle0_Y + paddleH))
      {
        ball_X++;                       // Move ball over one to the right
        ballVelocityX = -ballVelocityX; // Change velocity
      }
    }
    // Check if the ball hit the right paddle
    if (ball_X + ball_rad > paddle1_X)
    {
      // Check if ball is within paddle's height
      if ((ball_Y > paddle1_Y) && (ball_Y < paddle1_Y + paddleH))
      {
        ball_X--;                       // Move ball over one to the left
        ballVelocityX = -ballVelocityX; // change velocity
      }
    }
    // Check if the ball hit the top or bottom
    if ((ball_Y <= ball_rad) || (ball_Y >= (oled.getLCDHeight() - ball_rad - 1)))
    {
      // Change up/down velocity direction
      ballVelocityY = -ballVelocityY;
    }
    // Move the paddles up and down
    paddle0_Y += paddle0Velocity;
    paddle1_Y += paddle1Velocity;
    // Change paddle 0's direction if it hit top/bottom
    if ((paddle0_Y <= 1) || (paddle0_Y > oled.getLCDHeight() - 2 - paddleH))
    {
      paddle0Velocity = -paddle0Velocity;
    }
    // Change paddle 1's direction if it hit top/bottom
    if ((paddle1_Y <= 1) || (paddle1_Y > oled.getLCDHeight() - 2 - paddleH))
    {
      paddle1Velocity = -paddle1Velocity;
    }

    // Draw the Pong Field
    oled.clear(PAGE); // Clear the page
    // Draw an outline of the screen:
    oled.rect(0, 0, oled.getLCDWidth() - 1, oled.getLCDHeight());
    // Draw the center line
    oled.rectFill(oled.getLCDWidth() / 2 - 1, 0, 2, oled.getLCDHeight());
    // Draw the Paddles:
    oled.rectFill(paddle0_X, paddle0_Y, paddleW, paddleH);
    oled.rectFill(paddle1_X, paddle1_Y, paddleW, paddleH);
    // Draw the ball:
    oled.circle(ball_X, ball_Y, ball_rad);
    // Actually draw everything on the screen:
    oled.display();
    delay(25); // Delay for visibility
  }
  delay(1000);
}

void textExamples()
{
  printTitle("Text!", 1);

  // Demonstrate font 0. 5x8 font
  oled.clear(PAGE);     // Clear the screen
  oled.setFontType(0);  // Set font to type 0
  oled.setCursor(0, 0); // Set cursor to top-left
  // There are 255 possible characters in the font 0 type.
  // Lets run through all of them and print them out!
  for (int i = 0; i <= 255; i++)
  {
    // You can write byte values and they'll be mapped to
    // their ASCII equivalent character.
    oled.write(i);  // Write a byte out as a character
    oled.display(); // Draw on the screen
    delay(10);      // Wait 10ms
    // We can only display 60 font 0 characters at a time.
    // Every 60 characters, pause for a moment. Then clear
    // the page and start over.
    if ((i % 60 == 0) && (i != 0))
    {
      delay(500);           // Delay 500 ms
      oled.clear(PAGE);     // Clear the page
      oled.setCursor(0, 0); // Set cursor to top-left
    }
  }
  delay(500); // Wait 500ms before next example

  // Demonstrate font 1. 8x16. Let's use the print function
  // to display every character defined in this font.
  oled.setFontType(1);  // Set font to type 1
  oled.clear(PAGE);     // Clear the page
  oled.setCursor(0, 0); // Set cursor to top-left
  // Print can be used to print a string to the screen:
  oled.print(" !\"#$%&'()*+,-./01234");
  oled.display(); // Refresh the display
  delay(1000);    // Delay a second and repeat
  oled.clear(PAGE);
  oled.setCursor(0, 0);
  oled.print("56789:;<=>?@ABCDEFGHI");
  oled.display();
  delay(1000);
  oled.clear(PAGE);
  oled.setCursor(0, 0);
  oled.print("JKLMNOPQRSTUVWXYZ[\\]^");
  oled.display();
  delay(1000);
  oled.clear(PAGE);
  oled.setCursor(0, 0);
  oled.print("_`abcdefghijklmnopqrs");
  oled.display();
  delay(1000);
  oled.clear(PAGE);
  oled.setCursor(0, 0);
  oled.print("tuvwxyz{|}~");
  oled.display();
  delay(1000);

  // Demonstrate font 2. 10x16. Only numbers and '.' are defined.
  // This font looks like 7-segment displays.
  // Lets use this big-ish font to display readings from the
  // analog pins.
  for (int i = 0; i < 25; i++)
  {
    oled.clear(PAGE);           // Clear the display
    oled.setCursor(0, 0);       // Set cursor to top-left
    oled.setFontType(0);        // Smallest font
    oled.print("A0: ");         // Print "A0"
    oled.setFontType(2);        // 7-segment font
    oled.print(analogRead(A0)); // Print a0 reading
    oled.setCursor(0, 16);      // Set cursor to top-middle-left
    oled.setFontType(0);        // Repeat
    oled.print("A1: ");
    oled.setFontType(2);
    oled.print(analogRead(A1));
    oled.setCursor(0, 32);
    oled.setFontType(0);
    oled.print("A2: ");
    oled.setFontType(2);
    oled.print(analogRead(A2));
    oled.display();
    delay(100);
  }

  // Demonstrate font 3. 12x48. Stopwatch demo.
  oled.setFontType(3); // Use the biggest font
  int ms = 0;
  int s = 0;
  while (s <= 5)
  {
    oled.clear(PAGE);     // Clear the display
    oled.setCursor(0, 0); // Set cursor to top-left
    if (s < 10)
      oled.print("00"); // Print "00" if s is 1 digit
    else if (s < 100)
      oled.print("0"); // Print "0" if s is 2 digits
    oled.print(s);     // Print s's value
    oled.print(":");   // Print ":"
    oled.print(ms);    // Print ms value
    oled.display();    // Draw on the screen
    ms++;              // Increment ms
    if (ms >= 10)      // If ms is >= 10
    {
      ms = 0; // Set ms back to 0
      s++;    // and increment s
    }
  }
}

void loop()
{
  //pixelExample();  // Run the pixel example function
  lineExample();  // Then the line example function
  shapeExample(); // Then the shape example
  textExamples(); // Finally the text example
}

// Center and print a small title
// This function is quick and dirty. Only works for titles one
// line long.
void printTitle(String title, int font)
{
  int middleX = oled.getLCDWidth() / 2;
  int middleY = oled.getLCDHeight() / 2;

  oled.clear(PAGE);
  oled.setFontType(font);
  // Try to set the cursor in the middle of the screen
  oled.setCursor(middleX - (oled.getFontWidth() * (title.length() / 2)),
                 middleY - (oled.getFontHeight() / 2));
  // Print the title:
  oled.print(title);
  oled.display();
  delay(1500);
  oled.clear(PAGE);
}

Grove_4Digit_displayのスケッチ(おまけ)

I2Cデバイスでないが Seeed-Studio/Grove_4Digit_DisplayをGROVE#6に接続して動作したスケッチを挙げる。
(CLKとDIOに修正を加えた)

NumberFlow_MAKER.ino


/*
 * TM1637.cpp
 * A library for the 4 digit display
 *
 * Copyright (c) 2012 seeed technology inc.
 * Website    : www.seeed.cc
 * Author     : Frankie.Chu
 * Create Time: 9 April,2012
 * Change Log :
 *
 * The MIT License (MIT)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "TM1637.h"
/*
#define CLK 2//pins definitions for TM1637 and can be changed to other ports
#define DIO 3
*/
// for MAKER PI RP2040
#define CLK 27 //pins definitions for TM1637 and can be changed to other ports
#define DIO 26


TM1637 tm1637(CLK,DIO);
void setup()
{
  tm1637.init();
  tm1637.set(BRIGHT_TYPICAL);//BRIGHT_TYPICAL = 2,BRIGHT_DARKEST = 0,BRIGHTEST = 7;
}
void loop()
{
  int8_t NumTab[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};//0~9,A,b,C,d,E,F
  int8_t ListDisp[4];
  unsigned char i = 0;
  unsigned char count = 0;
  delay(150);
  while(1)
  {
    i = count;
    count ++;
    if(count == sizeof(NumTab)) count = 0;
    for(unsigned char BitSelect = 0;BitSelect < 4;BitSelect ++)
    {
      ListDisp[BitSelect] = NumTab[i];
      i ++;
      if(i == sizeof(NumTab)) i = 0;
    }
    tm1637.display(0,ListDisp[0]);
    tm1637.display(1,ListDisp[1]);
    tm1637.display(2,ListDisp[2]);
    tm1637.display(3,ListDisp[3]);
    delay(1000); //(300);
  }
}

platformio.ini

I2Cを使用しているときは、現状、本件でplaatformioは使用できないが、
参考のためにplatformio.iniを挙げる:

MAKER_PI_RP2040用:
platformio.ini


[env:pico]
platform = https://github.com/platformio/platform-raspberrypi.git
framework = arduino
board = pico

upload_port  = /dev/ttyACM0  
monitor_port  = /dev/ttyACM0         ; directory for usb-over-serial 
monitor_speed = 115200

lib_deps = 
    seeed-studio/Grove 4-Digit Display@^1.0.0
    

参考情報

terminal関連:
Bootterm – a developer-friendly serial terminal program

MAKER PI RP2040関連:
MAKER PI RP2040 - Datasheet Rev 1.2 January 2022
Maker Pi RP2040 Schematic.pdf

platformio関連: arduinoフレームワーク用platformio.ini集
Building Core2 FactoryDemo in PlatformIO
VSCodeとPlatformIOでM5Stack Core2開発
M5Stack Core2とVSCode + PlatformIOとでM5Stackプログラミングを始めてみた。

Arduino-IDE関連:
Raspberry Pi PicoでI2C/SPI通信
Arduino IDE environment - M5Paper
Arduino IDEのインストールと設定 (Windows, Mac, Linux対応)

以上