Connecting I2C stuff

[nicolasdb]

https://docs.m5stack.com/en/unit/envIII

And example but for M5 ATOM. I didn't find anything about stamp C3 for now.
https://www.hackster.io/hague/m5atom-env-mini-data-monitor-026469

basically, this is what I want to do, but with other hardware ^^'

https://randomnerdtutorials.com/esp32-data-logging-temperature-to-microsd-card/

CJMCU-758 + ESP32 measuring current
https://www.youtube.com/watch?v=alAly-oTha0

[nicolasdb]

Library for M5 all models
https://github.com/m5stack/M5Unified

for ENV unit
https://github.com/m5stack/M5Unit-ENV

for display
https://github.com/m5stack/M5GFX

[nicolasdb]

Back to basics:
Communication ESP32 I2C
https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/

I'll try to connect in I2C:

• a display OLED GME12864
• the ENV III Unit with SHT30 + QMP6988

according to its datasheet any GPIO can be used for I2C.

The SDA and SCL lines are active low, so they should be pulled up with resistors. Typical values are 4.7k Ohm for 5V devices and 2.4k Ohm for 3.3V devices.

4.7K since here ENV III is 5V

[nicolasdb]

Instead of connecting real gadgets to your Arduino IDE compatible microcontroller board for showing experiment results (or for getting simple input like clicking), you can make use of DumbDisplay for the purposes -- to realize virtual IO gadagets on your Android phone.

https://github.com/trevorwslee/Arduino-DumbDisplay

[nicolasdb]

A ESP32-C3 I2C OLED Project

It work with 0.96 i2c oled
https://github.com/monoliths-uni/ESP32-C3-IIC-OLED

https://passionelectronique.fr/ecran-oled-i2c-arduino/

Oled is working but not by default since the I2C pin are by default.
Must add this in my case:

#define I2C_SDA 6
#define I2C_SCL 7

and this in setup:
Wire.begin(I2C_SDA, I2C_SCL);

generator bitmap Arduino

https://javl.github.io/image2cpp/

working with Oled 0.96 submenu

https://home.et.utwente.nl/slootenvanf/2019/11/15/using-oled-display-with-arduino/

[nicolasdb]

Let's try with pin 6,7 with 4.7k.

[nicolasdb]

Lib to install :

• M5unit-ENV
• Wire
• M5gfx

I2C scan? YES

Let's try with pin 6,7 with 4.7k.

Scanning...
I2C device found at address 0x3C
done

Let's try on PORT A with pin 1,0

Scanning...
I2C device found at address 0x44
I2C device found at address 0x70
done

Everything connected on the same BUS

Scanning...
I2C device found at address 0x20
I2C device found at address 0x3C
I2C device found at address 0x44
I2C device found at address 0x70
done

MCP > 0x20
OLED > 0x3C
QMP6988 ?
SHT30 ?

[nicolasdb]

of course, nothing works. dedjeu

However, if you’re using libraries to communicate with those sensors, this might not work and it might be a bit tricky to select other pins. That happens because those libraries might overwrite your pins if you don’t pass your own Wire instance when initializing the library.

bon, il n'y a pas de raccourcis à la connaissance...

let's get back in theory
https://deepbluembedded.com/esp32-i2c-tutorial-change-pins-i2c-scanner-arduino/

[nicolasdb]

PORT A [1,0] > M5 ENVIII unit
Pin [6,7] > oled 12864 + MCP

I got the "blink" to work on MCP23017 through PIN 6,7 as I2C PORT
But to work using Two I2C Bus Interfaces, or more...
TwoWire command doesn't work with Adafruit_MCP23X17 lib.

[nicolasdb]

Env III unit

QMP6988 for pressure
SHT30 for temp and humidity.

Download the SHT30 sensor library from the link below and then install. (It is the same as SHT31)

[nicolasdb]

YUS!

Finaly made it work, with a DHT11 from keyestudio and the old dht11 library downloaded from their link.
Doc : https://wiki.keyestudio.com/Ks0034_keyestudio_DHT11_Temperature_and_Humidity_Sensor
Lib : https://fs.keyestudio.com/KS0034

The code is here:
https://github.com/nicolasdb/M5Stamp-C3U/blob/OledDHT11/src/main.cpp

[nicolasdb]

ESP32 BLE + Android + Arduino IDE = AWESOME

https://www.instructables.com/ESP32-BLE-Android-App-Arduino-IDE-AWESOME/

[nicolasdb]

MCP23017

Expand + 16 GPIO, but digital only.

[nicolasdb]