Hi everyone,
I decided to upgrade to Nano ESP32 to take advantage of ESP-Now capabilities. Unfortunately, the Dallas Thermistors do not respond once connected to the new board. Sketch works fine on Nano Every, but all I get is -196.6 for each thermistor on the Nano ESP32. Has anyone else seen this issue and do you have a work around to solve this problem? Thanks your insight is much appreciated.
Hi @kmaher4
welcome to the arduino-forum
after registering you have been presented a link to the
how to get the best out of this forum
You should take 20 minutes of your precious time to read it.
It will make you finish your project a minimum of 200 minutes faster.
You are working on an informatic project. And what is most needed in an informatic project is: information
If you look up the datasheet of the Arduino Nano ESP32
to what IO-pin did you connect the DS18B20-sensors?
You should post your complete sketch as a code-section like described here
best regards Stefan
1 Like
Hello kmaher4
Welcome to the worldbest Arduino forum ever.
Do the logic voltages used for the hardware components match?
Have a nice day and enjoy coding in C++.
I also had a problem with the DS18B20 and fixed it using the following which adds IRAM_ATTR to read_bit() write_bit() to solve timing issues caused by a cache miss.
1 Like
Thank you Stefan! Your post was extremely helpful.
I am have been using arduino hardware and environment for the past three years and have learned a lot. This was my first time posting tot he forum
To the community, I apologize for leading you into the mine without a flashlight or a map. Here is detailed information on how I am using the Nano ESP32 board along with the Sketch I am using successfully on a Nano Every.
- Current Board -- Nano ESP32. Powered by USB and connected to computer. I was able to swap out Every for ESP32 on the bread board and maintain pin config.
- two DS18B20's powered by 3.3v Pin with data line attached to Pin D2
along with the requisite 4.7K resistor bridged to the 3.3 v power - OLED display - powered by 3.3v pin and with SCL and SDA attached to pins A4 and A5,respectively
- Two Led indicator lights on D11 and D12
- Library versions:
- OneWire.h ver 2.3.7
- DallasTemperature ver 3.9.0
Everything works as before except the values from each of the thermistors read -196.6
Here is my code below:
//Set up libraries
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h> // for display
#include <Adafruit_SSD1306.h> // for display
#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 2 // Data wire is plugged into digital pin 2
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);// Pass oneWire reference to DallasTemperature library
#define WIRE Wire //configure I2C wire communications
Adafruit_SSD1306 display = Adafruit_SSD1306(128, 32, &WIRE); //configure OLED display
//configure Flow meter
#define HzPerLiter 5.5 //avg 5.5 pulses per liter
#define Pulses2Liter 330.0 //pulses per liter total
#define interval 5000.0 // interval for reporting in ms. divide by 1000 to get seconds
//global variables
const byte intrPin = 3; // define interupt pin as #3
float tempSensor1, tempSensor2; //declare temp sensors. ID to be read
by index in Get Temperatures routine
int Caution_YellowLED = 12;
int Warning_RedLED = 11;
float SetPointYellow = 37.5; //degrees F
float SetPointRed = 36; // degrees F
bool run_flag = false; // used to flash on board LED
unsigned long FlowTime = millis(); // variable to track time for flow meter
float LPerMin = 0 ; //liters per min variable
float GPM = 0 ; //gallons per min variable
volatile int rate_cnt = 0; //RATE of pulses(Hz) --> L/min resets every cycle
unsigned long total_cnt = 0; //Total Counts
unsigned long total_sec = 0; //total seconds since start +=interval/1000
unsigned long total_min = 0; //total minutes since start =total sec/60
float TotLit = 0; //total Liters = total count/pulse 2 liter
float TotGal = 0; //total gallons
float BTUexch = 0; //BTU exchanged
float Tot_Btu=0; //total Btu's exchanged
int header = 0; // counter for flag to print headers
char tbp[65];
void setup() {
sensors.begin(); // Start up the library for the thermistors
Serial.begin (9600); // initialize serial port
// PRINT FILE INFO loaded on board
delay(5000); // 5 second delay to allow time to open monitor to catch file name
Serial.println("Sketch Information "); Serial.println(F(__FILE__ " " __DATE__ " " __TIME__));
Serial.println();
pinMode(Caution_YellowLED, OUTPUT);
pinMode(Warning_RedLED, OUTPUT);
pinMode(LED_BUILTIN, OUTPUT); // output mode for on board LED
pinMode(intrPin, INPUT_PULLUP); //set interrupt pin and internal resistor
attachInterrupt(digitalPinToInterrupt(intrPin),Pulse_cnt,FALLING); // call subroutine
//set up and test display
// SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // Address 0x3C for 128x32
Serial.println("OLED begun");
// Show image buffer on the display hardware.
// Since the buffer is intialized with an Adafruit splashscreen internally, this will display the splashscreen.
display.display();
delay(1000);
// Clear the buffer.
display.clearDisplay();
display.display();
// set OLED text font to display results
display.setTextSize(2);
display.setTextColor(SSD1306_WHITE);
display.setCursor(0,0);
//flash LED to verify working
digitalWrite(Warning_RedLED, HIGH); // Initialize to blink LED on and off
delay (500);
digitalWrite(Warning_RedLED, LOW);
digitalWrite(Caution_YellowLED, HIGH);
delay (500);
digitalWrite(Caution_YellowLED, LOW); // Initialize LED to off
Serial.print("Water Flow - Approximate (Counts Exits) ");
sprintf(tbp, "Reports every %d seconds", round((interval+10000)/1000)); // format comment
Serial.println(tbp); // Print formatted comment
Serial.println();
}
void Pulse_cnt() { //count pulses for Hall Effect
rate_cnt++; //pulses per time
total_cnt++; // total pulses
run_flag = true; // On for LED 13 if meter turning
}
void GetTemperatures(){ //request temperatures from probes
sensors.requestTemperatures(); // ordered according to Hex address
tempSensor1 = sensors.getTempCByIndex(0)*1.8+32; // Gets temperature value thermistor based on index, converts to F
tempSensor2 = sensors.getTempCByIndex(1)*1.8+32; // Gets temperature value thermistor based on index, converts to F
}
void Write_2_Serial(){ // write to serial monitor with new header at 20 lines
if(header == 0) {
Serial.println (" EWT LWT Instant Flow BTU exchanged Totals since Startup ");
Serial.println (" F F GPM Kbtu/hr Gallons Minutes");
}
Serial.print(" ");Serial.print(tempSensor1);//EWT
Serial.print(" ");Serial.print(tempSensor2);//LWT
Serial.print(" ");Serial.print(GPM);Serial.print(" ");Serial.print(BTUexch);
Serial.print(" ");Serial.print (TotGal);Serial.print(" ");Serial.println (total_min);
header++; // increment counter to track when to print header on screen
if(header == 20) {
header = 0; //reset header
}
}
void Write_2_Display () { // light warning LED and write values to OLED Display - 2 pages worth
//check for conditions to light LED's
if (tempSensor2 < SetPointRed) {digitalWrite(Warning_RedLED, HIGH);}
if (tempSensor2 < SetPointYellow && tempSensor2 >= SetPointRed) {digitalWrite(Caution_YellowLED, HIGH);}
//page 1
display.print("EWT ");
display.println(tempSensor1);
display.print("LWT ");
display.println(tempSensor2);
display.setCursor(0,0);
display.display(); // actually display all of the above
delay (2000);// delay to hold page
//page 2
display.clearDisplay();//clear screen
display.display();
display.print("GPM ");
display.println(GPM);
display.print("BTU ");
display.println(BTUexch);
display.println(tempSensor2);
display.setCursor(0,0);
display.display(); // Display page 2
// clear display
delay(2000); //refresh every 5 seconds
display.clearDisplay();//clear screen
display.display();
digitalWrite(Warning_RedLED, LOW);digitalWrite(Caution_YellowLED, LOW); // turn off LEDs
}
void loop () {
GetTemperatures(); // Send command to the sensors to retrieve data and do temperature conversion
rate_cnt = 0; // reset flow rate counter every interval cycle
while(millis() - FlowTime <= interval){ // wait loop for interval cycle timing
//can add programming stuff in here
digitalWrite(LED_BUILTIN, LOW); // set run LED to OFF
if(run_flag){
digitalWrite(LED_BUILTIN, HIGH); // set run LED to ON
run_flag = false;
}
}
//Calculate flow values
//digitalWrite= (LED_BUILTIN, LOW); // set run LED to OFF
total_sec += interval/1000; // increment total seconds
total_min = round(total_sec/60); // calculate total minutes
LPerMin = (rate_cnt/(HzPerLiter*(interval/1000))); // pulses divided by meter parameters
TotLit = total_cnt/Pulses2Liter; //calc total liters
GPM = LPerMin * 0.264172; //GPM
TotGal = TotLit * 0.264172;
BTUexch = (tempSensor2-tempSensor1)*GPM*500/1000; // calculate instantaneous KBtu
Write_2_Serial(); // send data to Serial Monitor
Write_2_Display(); // send data to OLED
FlowTime = millis(); // get current "time" to start new cycle for flow meter
}type or paste code here
I suspect it might have something to do with the libraries not updated for the Nano ESP32?? I have spent hours searching for answers to no avail. Thank you to the community for your insight and your help is much appreciated!
1 Like
The IO-pin numeration on ESP32's is odd.
In the line above you define as IO-pin number 2.
But D2 ist not GPIO2
If you take a look at the PIN-Out
The IO-Pin named D2 is GPIO 5
So you either name it
#define ONE_WIRE_BUS D2
or
#define ONE_WIRE_BUS 5
best regards Stefan
1 Like
No way.
The "pin" with the red outline (above) is, simply 2 (it is not D2 or GPIO5).
Can you please explain why the official Arduino-Store website provides a datasheet that shows the pinout as I have posted it and all the IO-pin-numbering is wrong???
First page of the datasheet at
https://docs.arduino.cc/resources/datasheets/ABX00083-datasheet.pdf
page 14 of the document at
https://docs.arduino.cc/resources/datasheets/ABX00083-datasheet.pdf
??
I didn't say that's wrong.
The "D#" and/or "GPIO#" dumpster fire belongs to the NodeMCU world - it's not part of the Nano ESP32 program.
Just like with a 'classic nano' you do not digitalWrite(D2, HIGH) - you don't do that here either.
So at least this line of code should work
Assuming the connection is made at the pin marked D5 then I would expect as much.
Thank You Stefan. Changing it to 5 as in reference to GPIO5 worked! Problem solved.
I have to say it's a bit confusing. My references for the LED's at 11 and 12 work fine.., Not sure why the OneWire is requiring the GPIO # ?
I am grateful for the help. Thank you
Where exactly is the connection to??
I have the One wire Bus connected to Physical D2 on the board, but in the sketch, it needs to be referenced by GPIO 5 in order to work.
Meanwhile, I also have LED's physically connected to D11 and D12, and they are quite happy being referenced as 11 and 12 in the sketch. A bit confusing, but I am now back on track. Thanks!
1 Like
@lburelli
Comments?
I think you guys have pretty much figured out what the original problem was but I think it is worth clarifying for anyone else that has the same issue and comes across this thread for help.
The digital pin out posted by StefanL38 is color coded for two different programming languages, orange for c/c+ and yellow for micropython and the two cannot be mixed. When you use a digital IO pin in your program you must remove the D when programming in c and remove the letters GPIO when programming with micropython
@sumguy
Well the chap says that he has a combination of situations.
Seems fishy.
@runaway_pancake yes it does seem confusing but the way the Nano cheat sheet describes it is how it works for me using micropython.
EDIT I just had a look through some examples, it's hard to cover every scenario but I did find a micropython example that used GPIO5 (which for c would be D2) and it works just fine, the example assigns GPIO5 to chip select in a SDCard script.
sd=machine.SDCard(slot=2,cs=5)
@sumguy
Does your micropython do 11, 12 or GPIO 38,47?
Again, our friend here says he has LEDs on D11 and 12 that he digitalWrites to as 11, 12. But for some reason the DS18B20 wants to be connected to "D2" but programmed as 5. (His posted sketch doesn't look like micropython.)
When I digitalWrite to 5, then "D5" goes on/off as directed.
For clarification, I am using Arduino IDE 2.2.1. It doesn't make any sense to me why physical D2 would have to be called using the GPIO 05 designation for the OneWire. Its above my ability to understand what's going on , but Stefan's suggestion of using 5 worked.