Teensy and Adafruit TCA9548A

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phoenixperry

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Hello friends,

I am looking to run this code on the teensy and can't. I have 3 IMUs all with the same i2c address so I have to multiplex. Anyone know if this is supposed to work? Works on the arduino like a charm. Could someone maybe hint to a teensy fix?

Thanks so much,
Phoenix


https://learn.adafruit.com/adafruit-tca9548a-1-to-8-i2c-multiplexer-breakout/wiring-and-test

/**
* TCA9548 I2CScanner.pde -- I2C bus scanner for Arduino
*
* Based on code c. 2009, Tod E. Kurt, http://todbot.com/blog/
*
*/

#include "Wire.h"
extern "C" {
#include "utility/twi.h" // from Wire library, so we can do bus scanning
}

#define TCAADDR 0x70

void tcaselect(uint8_t i) {
if (i > 7) return;

Wire.beginTransmission(TCAADDR);
Wire.write(1 << i);
Wire.endTransmission();
}


// standard Arduino setup()
void setup()
{
while (!Serial);
delay(1000);

Wire.begin();

Serial.begin(115200);
Serial.println("\nTCAScanner ready!");

for (uint8_t t=0; t<8; t++) {
tcaselect(t);
Serial.print("TCA Port #"); Serial.println(t);

for (uint8_t addr = 0; addr<=127; addr++) {
if (addr == TCAADDR) continue;

uint8_t data;
if (! twi_writeTo(addr, &data, 0, 1, 1)) {
Serial.print("Found I2C 0x"); Serial.println(addr,HEX);
}
}
}
Serial.println("\ndone");
}

void loop()
{
}
 
It would probably help to have additional information, like how everything is wired. And which Arduino... Can you talk to one IMU without the multiplexer? Which Teensy?...

Also it makes it easier to read your code when you put it in code tages (use the # button in toolbar)

Looks like standard old I2C scanner, modified to work with your chip... Maybe modify the Wire scanner (example program under teensy Wire library) to also use your scanner... Probably would looks something like:

Code:
// --------------------------------------
// i2c_scanner
// http://playground.arduino.cc/Main/I2cScanner
//
// 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
//    http://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>

#define TCAADDR 0x70

void tcaselect(uint8_t i) {
  if (i > 7) return;

  Wire.beginTransmission(TCAADDR);
  Wire.write(1 << i);
  Wire.endTransmission();
}


void setup() {
  // uncomment these to use alternate pins
  //Wire.setSCL(16);
  //Wire.setSDA(17);
  Wire.begin();
  Serial.begin(9600);
  while (!Serial);        // Leonardo: wait for serial monitor
  Serial.println(F("\nI2C Scanner"));
}


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

  for (uint8_t t = 0; t < 8; t++) {
    tcaselect(t);
    Serial.print("TCA Port #"); Serial.println(t);

    Serial.println(F("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(F("Device found at address 0x"));
        if (address < 16) {
          Serial.print("0");
        }
        Serial.print(address, HEX);
        Serial.print("  (");
        printKnownChips(address);
        Serial.println(")");

        nDevices++;
      } else if (error == 4) {
        Serial.print(F("Unknown error at address 0x"));
        if (address < 16) {
          Serial.print("0");
        }
        Serial.println(address, HEX);
      }
    }
    if (nDevices == 0) {
      Serial.println(F("No I2C devices found\n"));
    } else {
      Serial.println(F("done\n"));
    }
  }
  delay(5000);           // wait 5 seconds for next scan
}


void printKnownChips(byte address)
{
  // Is this list missing part numbers for chips you use?
  // Please suggest additions here:
  // https://github.com/PaulStoffregen/Wire/issues/new
  switch (address) {
    case 0x00: Serial.print(F("AS3935")); break;
    case 0x01: Serial.print(F("AS3935")); break;
    case 0x02: Serial.print(F("AS3935")); break;
    case 0x03: Serial.print(F("AS3935")); break;
    case 0x0A: Serial.print(F("SGTL5000")); break; // MCLK required
    case 0x0B: Serial.print(F("SMBusBattery?")); break;
    case 0x0C: Serial.print(F("AK8963")); break;
    case 0x10: Serial.print(F("CS4272")); break;
    case 0x11: Serial.print(F("Si4713")); break;
    case 0x13: Serial.print(F("VCNL4000,AK4558")); break;
    case 0x18: Serial.print(F("LIS331DLH")); break;
    case 0x19: Serial.print(F("LSM303,LIS331DLH")); break;
    case 0x1A: Serial.print(F("WM8731")); break;
    case 0x1C: Serial.print(F("LIS3MDL")); break;
    case 0x1D: Serial.print(F("LSM303D,LSM9DS0,ADXL345,MMA7455L,LSM9DS1,LIS3DSH")); break;
    case 0x1E: Serial.print(F("LSM303D,HMC5883L,FXOS8700,LIS3DSH")); break;
    case 0x20: Serial.print(F("MCP23017,MCP23008,PCF8574,FXAS21002,SoilMoisture")); break;
    case 0x21: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x22: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x23: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x24: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x25: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x26: Serial.print(F("MCP23017,MCP23008,PCF8574")); break;
    case 0x27: Serial.print(F("MCP23017,MCP23008,PCF8574,LCD16x2,DigoleDisplay")); break;
    case 0x28: Serial.print(F("BNO055,EM7180,CAP1188")); break;
    case 0x29: Serial.print(F("TSL2561,VL6180,TSL2561,TSL2591,BNO055,CAP1188")); break;
    case 0x2A: Serial.print(F("SGTL5000,CAP1188")); break;
    case 0x2B: Serial.print(F("CAP1188")); break;
    case 0x2C: Serial.print(F("MCP44XX ePot")); break;
    case 0x2D: Serial.print(F("MCP44XX ePot")); break;
    case 0x2E: Serial.print(F("MCP44XX ePot")); break;
    case 0x2F: Serial.print(F("MCP44XX ePot")); break;
    case 0x38: Serial.print(F("RA8875,FT6206")); break;
    case 0x39: Serial.print(F("TSL2561")); break;
    case 0x3C: Serial.print(F("SSD1306,DigisparkOLED")); break;
    case 0x3D: Serial.print(F("SSD1306")); break;
    case 0x40: Serial.print(F("PCA9685,Si7021")); break;
    case 0x41: Serial.print(F("STMPE610,PCA9685")); break;
    case 0x42: Serial.print(F("PCA9685")); break;
    case 0x43: Serial.print(F("PCA9685")); break;
    case 0x44: Serial.print(F("PCA9685")); break;
    case 0x45: Serial.print(F("PCA9685")); break;
    case 0x46: Serial.print(F("PCA9685")); break;
    case 0x47: Serial.print(F("PCA9685")); break;
    case 0x48: Serial.print(F("ADS1115,PN532,TMP102,PCF8591")); break;
    case 0x49: Serial.print(F("ADS1115,TSL2561,PCF8591")); break;
    case 0x4A: Serial.print(F("ADS1115")); break;
    case 0x4B: Serial.print(F("ADS1115,TMP102")); break;
    case 0x50: Serial.print(F("EEPROM")); break;
    case 0x51: Serial.print(F("EEPROM")); break;
    case 0x52: Serial.print(F("Nunchuk,EEPROM")); break;
    case 0x53: Serial.print(F("ADXL345,EEPROM")); break;
    case 0x54: Serial.print(F("EEPROM")); break;
    case 0x55: Serial.print(F("EEPROM")); break;
    case 0x56: Serial.print(F("EEPROM")); break;
    case 0x57: Serial.print(F("EEPROM")); break;
    case 0x58: Serial.print(F("TPA2016,MAX21100")); break;
    case 0x5A: Serial.print(F("MPR121")); break;
    case 0x60: Serial.print(F("MPL3115,MCP4725,MCP4728,TEA5767,Si5351")); break;
    case 0x61: Serial.print(F("MCP4725,AtlasEzoDO")); break;
    case 0x62: Serial.print(F("LidarLite,MCP4725,AtlasEzoORP")); break;
    case 0x63: Serial.print(F("MCP4725,AtlasEzoPH")); break;
    case 0x64: Serial.print(F("AtlasEzoEC")); break;
    case 0x66: Serial.print(F("AtlasEzoRTD")); break;
    case 0x68: Serial.print(F("DS1307,DS3231,MPU6050,MPU9050,MPU9250,ITG3200,ITG3701,LSM9DS0,L3G4200D")); break;
    case 0x69: Serial.print(F("MPU6050,MPU9050,MPU9250,ITG3701,L3G4200D")); break;
    case 0x6A: Serial.print(F("LSM9DS1")); break;
    case 0x6B: Serial.print(F("LSM9DS0")); break;
    case 0x70: Serial.print(F("AdafruitLED")); break;
    case 0x71: Serial.print(F("SFE7SEG,AdafruitLED")); break;
    case 0x72: Serial.print(F("AdafruitLED")); break;
    case 0x73: Serial.print(F("AdafruitLED")); break;
    case 0x76: Serial.print(F("MS5607,MS5611,MS5637,BMP280")); break;
    case 0x77: Serial.print(F("BMP085,BMA180,BMP280,MS5611")); break;
    default: Serial.print(F("unknown chip"));
  }
}
Note: I did not exclude the address of your multiplexer, so it should find something, however it does think that the default for 0x70 is an Adafruit LED... So just be aware that is your multiplexer... Or edit the above and change it to either exclude it or edit the name that prints...
 
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