Because I was not satisfied with the information about the water temperature of the Baltic Sea during a past vacation stay, I built a thermometer with M5Stack components and a remote temperature sensor and presented it in a blog post. With the remote DS18B20 temperature sensor, I measured the water temperature at a depth of one meter.

Now the vacations are approaching again, and the message from the BSH still shows very cool water at the end of May.

I have extended the presented thermometer to follow the water temperature changes and be immune from bigger surprises.
Because of the slightly larger display, I replaced the M5StickC with an M5StickC+ and used an M5StickC 18650C to increase the battery capacity. In addition, the thermometer is much easier to handle.

To have the readings available on my mobile phone, I use it as a mobile hotspot and send the readings from the M5StickC+ via WiFi to the mobile phone, which then sends the data to the Pushover server. From there, the data is then distributed to the selected end devices.

This setup won't affect the water temperature, but I can record it in writing. And if it stays that cold, then I can document my heroism.

The link to the original post in German is https://wordpress.com/post/ckblog2016.net/4227

Here is a working code example:

/*

• Test of IP5306 functions
  */

#include <M5Stack.h>

void setup()
{
// initialize the M5Stack object
M5.begin();
Wire.begin(); // required to access IP5306
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setCursor(0, 10);
M5.Lcd.setTextColor(WHITE);
M5.Lcd.setTextSize(2);
M5.Lcd.printf("IP5306 Function Test\r\n");

if(!M5.Power.canControl())
{
M5.Lcd.setTextColor(RED);
M5.Lcd.printf("No communication with IP5306 chip");
while(1);
}
}

void loop()
{
M5.Lcd.fillRect(0,180,360,60,0);
uint8_t bat = M5.Power.getBatteryLevel();
M5.Lcd.setCursor(0,180);
if (M5.Power.isCharging()) M5.Lcd.printf("Battery is charging\r\n");
else M5.Lcd.printf("Battery is not charging\r\n");
M5.Lcd.printf("Battery Level %d", bat);
M5.Lcd.progressBar(0, 220, 360, 20, bat);
delay(5000);
}

Using the LoRa868 (old version) w/ Core Basic works as expected w/ precompiled meshtastic firmware. Thanks to @felmue for his hints.

If you want to use precompiled firmware then look into variants.h for the used GPIO and check your Core and LoRa Module whether the IO fits or not.

@felmue said in M5Stack Core Basic as Meshtastic Device:

Hi guys

I don't think you can use pre-compiled Meshtastic firmware as some GPIOs used in pre-compiled firmware cannot be selected in LoRa868 V1.1 module.

From the M5Stack Meshtastic variant.h file and the previous LoRa module I understand the following GPIOs are used:

SCK   : GPIO18
MISO  : GPIO19
MOSI  : GPIO23
CS/NSS: GPIO5
IRQ   : GPIO36
RST   : GPIO26

However the newer LoRa868 V1.1 module doesn't allow to select GPIO36 as IRQ nor GPIO26 as RST.

So I think you either need to compile Meshtastic firmware (with the correct GPIOs) yourself, get the older LoRa868 module or modify the V1.1 hardware.

Note: I do not have the necessary hardware to test this myself - so my above conclusions could be incorrect.

Thanks
Felix

Is there an answer from M5Stack specialists?

@kuriko After starting the app an the Core the screen shows the Meshtastic start screen followed by the output Critical Fault #3.

To use an M5Stack Core Basic as a Meshtastic device I connected a LoRa868 V1.1 to the Core. The DIP switches should be set to Core Basic. But my tries resulted always in critical fault #3. This means no LoRa module is connected. My DIP switch setup is not correct. How to set the DIP switch for M5Stack Core Basic?

Because I was not satisfied with the information about the water temperature of the Baltic Sea during a past vacation stay, I built a thermometer with M5Stack components and a remote temperature sensor and presented it in a blog post. With the remote DS18B20 temperature sensor, I measured the water temperature at a depth of one meter.

Now the vacations are approaching again, and the message from the BSH still shows very cool water at the end of May.

I have extended the presented thermometer to follow the water temperature changes and be immune from bigger surprises.
Because of the slightly larger display, I replaced the M5StickC with an M5StickC+ and used an M5StickC 18650C to increase the battery capacity. In addition, the thermometer is much easier to handle.

To have the readings available on my mobile phone, I use it as a mobile hotspot and send the readings from the M5StickC+ via WiFi to the mobile phone, which then sends the data to the Pushover server. From there, the data is then distributed to the selected end devices.

This setup won't affect the water temperature, but I can record it in writing. And if it stays that cold, then I can document my heroism.

The link to the original post in German is https://wordpress.com/post/ckblog2016.net/4227

There is no serial response from this unit. No answer to AT @ 115200. Any idea?

Please have a look to my blog https://ckblog2016.net/2018/03/03/esp32-adc-dac/. Sorry for German language.

Hi @felmue
It was a good idea to replace the PIR by a wire. I have tried that w/o success.
I have prepared a Vbat measuring to see if battery is ok when USB is disconnected.
The CoreInk had now 3588 loops w/o USB connected. The battery goes from 4.1 V to 3.721 V after all these cycles (one second each). The battery is ok.
Thanks again.
Claus

@felmue said in M5CoreInk wake up by EXT0 (PIR Hat):

gpio_hold_en(GPIO_NUM_12); // POWER_HOLD_PIN
gpio_deep_sleep_hold_en();

Hi Felix

This are the last commands in my setup() now - but w/o success:

  esp_sleep_enable_ext0_wakeup(GPIO_NUM_36,1); //1 = High, 0 = Low

  //Go to sleep now
  if (DEBUG) 
  {
    Serial.println("Going to sleep now");
    Serial.flush();
  }
  delay(2000);
  gpio_hold_en(GPIO_NUM_12); // POWER_HOLD_PIN
  gpio_deep_sleep_hold_en();
  esp_deep_sleep_start();

I want to wake up an M5CoreInk by EXT0 (PIR Hat).
If I connect USB counting works. If I disconnect the USB cable the display loses its contrast and the software crashes.
I have no idea what's wrong. A program with wakeup by timer works.
The source is saved at https://github.com/ckuehnel/Arduino2020/tree/master/M5Stack/CoreInk_PIR.
Any hint is welcome.
best regards, Claus