I have now tried using G0 and G26 (StickC) to connect as custom I2C to PaHUB with the ENV III attached, which works on Port A.

Via the PaHUB using the top hat pins (the pins an I2C hat uses). I get "Pahub unit maybe not connect", fine on Port A.

Basically, I wanted to try and setup an I2C ultrasonic module from vanilla blocks, without Add/+ing the module and in accordance with this Arduino code https://github.com/m5stack/M5-ProductExampleCodes/blob/master/Unit/ULTRA/Arduino/ULTRA/ULTRA.ino and this https://www.sgbotic.com/products/datasheets/sensors/sr04_i2c.py for guidance/inspiration.

If I could be confident in the sensor, then maybe move back to the hub, then back to multiple sensors following the Arduino and converting back to vanilla blocks, something like this https://dronebotworkshop.com/multiple-i2c-bus/

I also tried the "Scan I2C device" block, which doesn't find address of Ultrasonic (0x57) at freq 400000 - fine for ENV III [0x44, 0x70] and PaHub [0x70] – ENV III on its own definitely scans as two addresses. freq reduced to 100000 it finds the ultrasonic address.

If I try and use the "Available I2C address in list" block I get I2C bus error (19) message (StickC and Core2), any help appreciated on why.

I'd really like to figure this out as I2C ultrasonic sensor arrays would be extremely useful for driving vehicles.

I think that need just to add a simple function to the PbBoard for ultrasonic sensors like this - https://github.com/ErickSimoes/Ultrasonic/blob/master/src/Ultrasonic.cpp
Because I can't to it through blocks or python, it's microseconds between send a receive an impulse.

Yeah, it's a bit disappointing because it's a common use case, multiples of the same ultrasonic sensors.

One thought, could you use the hat GPIO pins at the top of the StickC for the now IO ultrasonic sensor?

M5 engineers could you please add a function "get distance from ultrasonic" for PbHub?

1x StickC (freshly flashed from M5Burner v1.12.4)
1x M5Stack I2C Hub 1 to 6 Expansion Unit (PCA9548APW) SKU: U040-B
2x M5Stack Ultrasonic Distance Unit I2C (RCWL-9620) SKU: U098-B1

Strating from a new UIFlow, click Run, and (drumroll please)... "X Ultrasonic unit maybe not connect", FFS.

The good news, I have a ENV III here, so I connected it and got the same error. Take out the Ultrasonic and it works fine (PaHub Added/+ or not). Excellent, so back to the blocks in UIFlow. I can see that the Ultrasonic unit from the ? link is SKU: U098, both of mine are SKU: U098-B1 – the "Sonic" rather than "Ultrasonic", no unit for that in UIFlow. Comparing the notes for U098 vs U098-B1, I came across this line: "This allows for easy I2C integration and multi-sensor operation using a single BUS, to save I/O resources.", interesting.

Hmm, [now rummaging around for all sorts of hardware] Groove2Duponts, check, breadboard, check, off we go...

Switched to Core2 and transferred all the rest of the hardware, inc. PaHub, same UIFlow setup, and guess what... it works as expected. Two independent readings/labels. NB Keep sensors a little bit apart to avoid cross talk.

I tried additionally with power from I2C port of Core2 and no change “X Ultrasonic unit maybe not connect”. Very annoying.

There are 2 hard problems in computer science: cache invalidation, naming things, and off-by-1 errors :D

#include <M5StickCPlus.h>
#include <Unit_Sonic.h>
#include "ClosedCube_TCA9548A.h"

#define PaHub_I2C_ADDRESS 0x70
ClosedCube::Wired::TCA9548A tca9548a;

SONIC_I2C sensor;

void setup() {
    M5.begin();
    tca9548a.address(PaHub_I2C_ADDRESS);
    sensor.begin();
    M5.Lcd.setTextFont(2);
}

void loop() {
  static float newvalue = 0;
  for (uint8_t channel = 0; channel < 3; channel++) {
    tca9548a.selectChannel(channel);
    M5.Lcd.printf("%i = ", channel);
    newvalue = sensor.getDistance();
    if ((newvalue < 4000) && (newvalue > 20)) {
      M5.Lcd.printf("%.2fmm   ", newvalue);
    } else {
      M5.Lcd.print("ERR        ");
    }
    M5.Lcd.print("\n");
  }
  delay(20);
  M5.Lcd.setCursor(0,0);
}

Other than that, perhaps just recheck all again from the top, right StickC model (original or Plus), right units for PaHUB and Ultrasonic, etc. Did you want to add some screenshots from UIFlow, Blocky, Python, etc. Maybe with a few pairs of eyes we can spot something (remember to hide your API Key).

@teastain : See example here.

@gavin67890 : yes it still works when I add PaHub as unit on Port A.

@robot_alf : have you tried something similar in UiFlow/Micropython? E.g. only adding one Ultrasontic unit and then manually select the PaHub port/channel?

Thanks
Felix

#include <M5StickCPlus.h>
#include <Unit_Sonic.h>
#include "ClosedCube_TCA9548A.h"

#define PaHub_I2C_ADDRESS 0x70
ClosedCube::Wired::TCA9548A tca9548a;

SONIC_I2C sensor;

void setup() {
    M5.begin();
    tca9548a.address(PaHub_I2C_ADDRESS);
    sensor.begin();
    M5.Lcd.setTextFont(2);
    M5.Lcd.setTextColor(YELLOW, TFT_BLACK);
    M5.Lcd.println(("PaHUB Example"));
    M5.Lcd.setTextColor(TFT_WHITE, TFT_BLACK);
}

void loop() {
  static float newvalue = 0;
  for (uint8_t channel = 0; channel < 6; channel++) {
    tca9548a.selectChannel(channel);
    M5.Lcd.print(channel);
    M5.Lcd.print(" = ");
    newvalue = sensor.getDistance();
    if ((newvalue < 4000) && (newvalue > 20)) {
      M5.Lcd.printf("%.2fmm", newvalue);
    } else {
      M5.Lcd.print("ERR");
    }
    M5.Lcd.print("\n");
  }
  delay(20);
  M5.Lcd.fillScreen(BLACK);
  M5.Lcd.setCursor(0,0);
}

the following worked for me (M5StickCPlus fw 1.12.3, PaHub, 2x ultrasonic unit *)).

*) I don't actually have an ultrasonic unit - I simulated two of them with two ESP32C3 acting as I2C slaves on address 0x57.

Note: I did not add PaHub as unit. Just the two Ultrasonic units.

from m5stack import *
from m5ui import *
from uiflow import *
import unit

setScreenColor(0x111111)
Ultrasonic_0 = unit.get(unit.ULTRASONIC, unit.PAHUB0)
Ultrasonic_1 = unit.get(unit.ULTRASONIC, unit.PAHUB1)

label0 = M5TextBox(37, 38, "label0", lcd.FONT_Default, 0xFFFFFF, rotate=0)
label1 = M5TextBox(38, 115, "label1", lcd.FONT_Default, 0xFFFFFF, rotate=0)

label0.setText(str(Ultrasonic_0.distance))
label1.setText(str(Ultrasonic_1.distance))

Edit: I just thrown in four additional I2C units (RFID, EXT.IO2, Gesture and 4 Relay), all connected to the PaHub and everything still works fine for me.

Thanks
Felix