@mati I have mentioned this to Jimmi, and his answer basically was, well don't use wifi and OLED. Not exactly a practical answer. I'd rather have a long hat, isolating the DHT and BMP from the heat.

A screenshot or full text of the error would be helpful...

If you have the OLED and WiFi on, the heat they produce will skew the results. I connect the ENV hat to my Stick C with wires, and I get different, lower-temp results.

MOSI/MISO is the SPI equivalent of Tx/Rx for UART (except the lines are not crossed: MOSI connects to MOSI, and MISO to MISO). The other difference is that's it's a bus, like I2C, with one master and one or more slaves. So you can connect a screen and a LoRa chip, for instance. However, you need a separate SS (Slave Select) line per device. You're going to have difficulties finding enough pins for this. As suggested, it'd be much better to use a managed chip (MCU + LoRa chip).

I've tried a few things but it's too cumbersome. I switched back to M5Stack for this.

In my code I was using Wire instead of Wire1... So by changing that it worked.

The datasheet has most of the registers explained. I have the Chinese version, so it requires a little squinting (my Chinese is ok but nowhere near the level required to read datasheets with a smile pasted on my face ;-).

However I recently spent some quality time with the source code and the datasheet, so I have that more or less nailed down.

Register 46H is IRQ Status 3. Bits 0/1 are for the button:

// 0 not press, 0x01 long press, 0x02 press
uint8_t AXP192::GetBtnPress() {
  Wire1.beginTransmission(0x34);
  Wire1.write(0x46);
  Wire1.endTransmission();
  Wire1.requestFrom(0x34, 1);
  uint8_t state = Wire1.read();
  if (state) {
    Wire1.beginTransmission(0x34);
    Wire1.write(0x46);
    Wire1.write(0x03);
    Wire1.endTransmission();
  }
  return state;
}

In Wire1.write(0x03); 0x03 is the two bits 0 and 1 set.

There are many more registers, and the best would be to get a datasheet in English and read the registers description.

It should be 34. From MPU9250.cpp:

// Configure Interrupts and Bypass Enable
// Set interrupt pin active high, push-pull, hold interrupt pin level HIGH until interrupt cleared,
// clear on read of INT_STATUS, and enable I2C_BYPASS_EN so additional chips
// can join the I2C bus and all can be controlled by the Arduino as master
writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
delay(100);

0x22 = 34.

Nice list.

Espressif recommends you turn off BT, ADC and WiFi yourself before going to deep sleep, as the ESP32 doesn't do it "gracefully". Something like this:

esp_wifi_stop();
esp_bluedroid_disable();
esp_bluedroid_deinit();
esp_bt_controller_disable();
esp_bt_controller_deinit();
esp_bt_mem_release(ESP_BT_MODE_BTDM);
adc_power_off();
esp_deep_sleep_start();

I have a lot of different LoRa chips and setups. I have one board, at 230 MHz, that I can connect through the hat connector (I need 3 pins + Vcc/GND). I have transceivers, both at 230 and 433 MHz, I connect to via RS485 (I bought a hat for that, and also some RS485 for my M5Stack cores). etc etc. The smaller the better :-)

@ws1088 Funny enough I bought my M5StickC with the watch strap and all, but not because I wanted a watch – I don't wear them – but because it enables me to tie it up to my backpack when I do LoRa range tests :-)