Ok, so I got my hands on an Ender3 printer. So far so good, very impressed for the price. But could someone tell me what causes this?

Thanks everyone, good advice. A bit of trial and error learning, with a vertical learning curve...
Looks like I may go for either the Creality CR10 or the Ender 3, then have a play printing some existing items to see whats possible before I do my own designs.

Well, I didnt think this post would get so popular! but thats great, have learnt a lot just by looking suggested things up.

So, Software....

I am thinking of using sketchup as I already use this quite a bit for different projects and can find my way around it well.
Has anyone else used it and think there is better? Preferably free or open source...

What's everyone's preference?

All great advice everyone, thanks for the input!

Update -:
Stop the bus, just found a solution!
For anyone else searching I changed this in the sitemap

Text item=LastUpdate01 label="Last seen [%1$tA, %1$td/%1$tm/%1$tY %1$tH:%1$tM]" icon="network"

Works perfect now!

Hi Everyone,
I am having trouble getting 'Lastupdate' to work.

I have included

DateTime LastUpdate01 "Last Update"     { channel="mysensors:multimeter:gateway:multimeter_3_3:lastupdate" }

in my items file.

I am seeing this in Openhab Log

2019-06-11 19:28:46.275 [vent.ItemStateChangedEvent] - LastUpdate01 changed from 2019-06-11T19:12:52.000+1200 to 2019-06-11T19:28:46.000+1200

Added this to my sitemap

Text item=LastUpdate01 label="Last seen" icon="network"

But no data is being displayed in my sitemap?
What have I done wrong this time??
Thanks for any advice.

@fredswed Hi, did you ever get this sorted out? I am facing the same issue and cant find out whats going on.

Thanks for the response. All good points that I will investigate. I am happy with the engineering (avionics Eng by trade) etc
At the moment I am looking at the Ender 3 pro but still researching.
Cheers

Ok I am thinking of getting a 3d printer but do not know where to start and what to stay clear of!
What's everyone using in the way of printer and software?
Any advice greatly appreciated!

@bgunnarb thanks for the reply. That’s what I thought, that the battery monitor is included in the library. I just don’t know how that part gets the info through to openHAB. I am using the Ethernet gateway by the way. I have managed to get the info through using the multimeter function but I think there is a better way for battery level!

@dbemowsk Hi, Thanks for the reply. I am very new to Mysensors and not a programmer. I think the sendbatteryLevel is part of the included libraries but not fully sure. I am seeing both voltage and percent in the serial monitor but just cant work out how to send it through the gateway to the controller (openhab). I just cant work out what extra I need in the sketch to do this?

Hi All,
I am a bit confused again (its not hard..) I am trying to combine a previous sketch from @Boots33 with battery reporting to openhab. The tank sketch works great (Thanks Boots!) but I can not figure out how to send the battery level. Here is my adapted sketch-:

/*
  Sketch to read level of water in a round tank and  then send data back to controller
  uses MySensors V2 .

  Libraries used
  MySensors          https://www.mysensors.org/
  NewPing            https://bitbucket.org/teckel12/arduino-new-ping/wiki/Home
  SPI                 installed with arduino IDE

*/

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_NRF24
// Enabled repeater feature for this node
//#define MY_REPEATER_FEATURE

//#define MY_RF24_CHANNEL 84    // channel of nrf network

#include <MySensors.h>
#include <SPI.h>
#include <NewPing.h>

#define MY_NODE_ID 3    // comment out this line if you use dynamic id's
#define CHILD_ID_WATER 1
#define CHILD_ID_PERCENT 2


// newping settings
#define TRIGGER_PIN  6                  // Arduino pin 6 connected to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     7                  // Arduino pin 7 connected to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 240                // Maximum distance we want to ping for (in centimeters). you should set this to be 
// a bit more than fullHeight + sensHeight.

/*------change these to suit your tank setup-----*/
const int tankRad = 170;                // Radius of tank in cm
const int fullHeight = 198;             // Height of water when tank full in cm
const int sensHeight = 30;              // height of sensor above full water mark in cm
const int outletHeight = 7;             // height of water when tank reading will show empty in cm
/*----------------------------------------------*/

int BATTERY_SENSE_PIN = A0;             // select the input pin for the battery sense point
int oldBatteryPcnt = 0;
unsigned long lastSent;
unsigned long heartbeatDelay = 15;     // how often the heartbeat will be sent, in minutes
//unsigned long lastHeartbeat = millis(); // holder for last time heartbeat was sent
uint32_t SLEEP_TIME = 10000;           // 900000=15 mins sleep time between reads (seconds * 1000 milliseconds)
unsigned long pingHeight;               // holds total height from ultrasonic sender to current water height
unsigned int waterAvail;                // holds current water available in litres

byte oldWaterPercent;
byte waterPercent = 0 ;                 // used to hold the tank water level percentage

// NewPing setup of pins and maximum distance.
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

MyMessage msgVolume(CHILD_ID_WATER, V_LEVEL);              // water available in litres
MyMessage msgPercent(CHILD_ID_PERCENT, V_LEVEL);           // water percentsge available

void setup() {

  pinMode(5, OUTPUT);
  analogReference(INTERNAL);
}

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Tank Level", "1.4");

  // Register all sensors to gateway (they will be created as child devices)
  present(CHILD_ID_WATER, S_DUST, "Water Available");
  present(CHILD_ID_PERCENT, S_DUST, "Water Percentage Available");
}


void loop()
{
// get the battery Voltage
int sensorValue = analogRead(BATTERY_SENSE_PIN);
#ifdef MY_DEBUG
Serial.println(sensorValue);
#endif

// 1M, 470K divider across battery and using internal ADC ref of 1.1V
// Sense point is bypassed with 0.1 uF cap to reduce noise at that point
// ((2.2e6+330e3)/330e3)*1.1 = Vmax = 8.4 Volts
// 8.4/1023 = Volts per bit = 0.001075275

int batteryPcnt = sensorValue / 10;

#ifdef MY_DEBUG
//float batteryV  = sensorValue * 0.001075275;
float batteryV = sensorValue * 9.17 / 1023;

Serial.print("Battery Voltage: ");
Serial.print(batteryV);
Serial.println(" V");

Serial.print("Battery percent: ");
Serial.print(batteryPcnt);
Serial.println(" %");
#endif

if (oldBatteryPcnt != batteryPcnt) {
  // Power up radio after sleep
  sendBatteryLevel(batteryPcnt);
  oldBatteryPcnt = batteryPcnt;
}
{
  Serial.println("Waking out of sleep");
  digitalWrite(5, HIGH);
  Serial.println("Ultrasonic module ON");
  delay (1000);

  data_calc();      // perform calculations to get water remaining etc.


  if (oldWaterPercent != waterPercent) {        //check to see if new water data is available
    send(msgVolume.set(waterAvail));
    send(msgPercent.set(waterPercent));
    oldWaterPercent = waterPercent;
    lastSent = millis();
  }

  heartbeatCheck();                                    // call heartbeat function
  digitalWrite(5, LOW);
  Serial.println("Ultrasonic module OFF");

  Serial.println("Entering Sleep");
  sleep(SLEEP_TIME);

}
}
/*-------------------------start of functions-------------------*/

void heartbeatCheck() {
  unsigned long millisNow = millis();           // get the current time
  if ((millisNow - lastSent) > (heartbeatDelay * 60000)) {
    send(msgVolume.set(waterAvail));
    send(msgPercent.set(waterPercent));
    lastSent = millisNow;
  }

  /*if ((millisNow - lastHeartbeat) > (heartbeatDelay*60000)) {
    sendHeartbeat();
    wait(5);
    // sendBatteryLevel(100);
    lastHeartbeat = millis();
    #ifdef MY_DEBUG
      Serial.println("Heartbeat Sent" );
    #endif
    } */
}

void data_calc() {
  pingHeight = sonar.ping_median(5);             //- Do multiple (5) pings and return median
  pingHeight = sonar.convert_cm(pingHeight);     // then convert to cm
#ifdef MY_DEBUG
  Serial.print("Ping Height raw in cm: ");
  Serial.println(pingHeight);
#endif
  pingHeight  = constrain(pingHeight, sensHeight, (fullHeight - outletHeight) + sensHeight); // keep pingHeight within the expected values
  waterPercent = map(pingHeight, sensHeight, (fullHeight - outletHeight) + sensHeight, 100, 0);   // calculate the percentage of water available
  waterAvail = PI * pow(tankRad, 2) * (((fullHeight - outletHeight) + sensHeight) - pingHeight) / 1000; // calculate water available in litres

  // Write some debug info
#ifdef MY_DEBUG
  Serial.print("Ping Height constrained in cm: ");
  Serial.println(pingHeight);
  Serial.print("Percentage Available: ");
  Serial.println(waterPercent);
  Serial.print("Litres Available: ");
  Serial.println(waterAvail);
#endif
}

I am trying to figure out how the sketch sends the battery info to openhab and how I view it. Any tips or pointers would be most appreciated. Do I have to add another line in the void presentation for the voltage? And should Openhab discover the voltage data as another Thing?

Cheers
Crumpy

@electrik Not sure what it would be at 8.4v because that would be two fully charged 18650's and the two I have on test are currently giving 7.80v on the multimeter and returning about 870 on the serial monitor, reporting battery at 0.94v and 86%

I would need to fully recharge two batteries later to tell what the max would be.

@mfalkvidd been there already but thanks.

@electrik Hi, the 2.2Meg is connected to the battery and the 330k is connected to GND.

Cheers

@mfalkvidd Well thanks for looking at it, at least my maths is still working ok! Perhaps someone else may know whats going on...

The strange thing is if I use this line-:

float batteryV = sensorValue * 8.6 / 1023;

I can get close. I found another thread where @TimO was using 7.2v with this in his sketch-:

float batteryV = sensorValue * 6.1 / 1023;

So I just increased the 6.1 slowly until my read value was close to my multimeter voltage. But I dont understand what the 6.1 in this line of code is doing, or where it comes from...

@mfalkvidd I have left the analogReference as it was in the original like this-:

void setup()
{
	// use the 1.1 V internal reference
#if defined(__AVR_ATmega2560__)
	analogReference(INTERNAL1V1);
#else
	analogReference(INTERNAL);
#endif
}

void presentation()
{
	// Send the sketch version information to the gateway and Controller
	sendSketchInfo("Battery Meter", "1.0");
}

Just for learning about battery monitoring, I am using a Nano with two 18650's in series to power it. in my final project I will be using a Pro Mini. Unfortunately the ultrasonic sensor I need to use is a 5v sensor and needs a good supply. Hence learning about monitoring the 18650's.
Cheers.

Thanks for the reply.

Hi Guys,

I have been playing around with the Battery Powered Sensor sketch, trying to get it to report correctly the level of 2x 18650 batteries. I am not a programmer and am getting a bit lost with the sketch. I have a voltage divider of 2.2Meg and 330K, So in my calculations 2 x 18650 batteries give me a max voltage of 8.4vdc fully charged, therefore with that divider Vout should be 1.096vdc or around that. So I have calculated that my Vmax is 1.100007332 and my Volts per bit for the sketch should be 0.001075275.
But when I run the sketch I am getting around 1vdc on the serial monitor, when the voltmeter is reading 7.90vdc

Heres the Loop part of my sketch, can some one point out my mistakes please?

void loop()
{
	// get the battery Voltage
	int sensorValue = analogRead(BATTERY_SENSE_PIN);
#ifdef MY_DEBUG
	Serial.println(sensorValue);
#endif

	// 1M, 470K divider across battery and using internal ADC ref of 1.1V
	// Sense point is bypassed with 0.1 uF cap to reduce noise at that point
	// ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
	// 3.44/1023 = Volts per bit = 0.003363075

	int batteryPcnt = sensorValue / 10;

#ifdef MY_DEBUG
	float batteryV  = sensorValue * 0.001075275;
 
	Serial.print("Battery Voltage: ");
	Serial.print(batteryV);
	Serial.println(" V");

	Serial.print("Battery percent: ");
	Serial.print(batteryPcnt);
	Serial.println(" %");
#endif

	if (oldBatteryPcnt != batteryPcnt) {
		// Power up radio after sleep
		sendBatteryLevel(batteryPcnt);
		oldBatteryPcnt = batteryPcnt;
	}
	sleep(SLEEP_TIME);
}

Thanks

@TimO ,
Thanks for the reply.

OK So if I can use a mixture of either self discovery and files thats fine BUT as soon as I un-comment the sensors in mysensors.items the thing sensors double up in Openhab? See below?

Openhab discovered the highlighted sensors (only after I reset the sensor node!) and then when I ticked the discovered sensors it added the extra two sensors not highlighted?!? Weird as I have only one DHT11 sensor... Any ideas whats going on?

I started out this evening by deleting the sensors and the gateway in openhab, restarted openhab. I then added the gateway, reset the node which added the 4 things.
Now I am getting data on the sitemap for the first time! Eh.....
Should I have each sensor doubled up then? and I didnt link any channels either....

Now I am confused...
:thinking_face:

@pavel-hrudka I know this is quite an old post but I discovered tonight that when openHAB would not discover my node, I hit reset on the node and openHAB discovered the sensor when it restarted and contacted the GW. May help someone in the future!