Finally reworked code for the ds18b20 sensor, with the pin setting.
BTW, Adafruit_SSD1306 library can be used for temperature value displaying with the degree sign by such code:

B4X:
'Module name = "esp_ds18b20", (c) Peacemakerv
'v.2
'Libs: https://github.com/milesburton/Arduino-Temperature-Control-Library; https://github.com/PaulStoffregen/OneWire
Sub Process_Globals
'These global variables will be declared once when the application starts.
'Public variables can be accessed from all modules.
Private pin1wire As Pin
Public temperature_ds18b20 As Float 'centigrees
Private Timer1 As Timer
Dim Ready_flag As Boolean 'ignore
End Sub
Sub Start_ds18b20(pinNumber As Byte)
Log("Start reading ds18b20...")
pin1wire.Initialize(pinNumber, pin1wire.MODE_INPUT_PULLUP)
RunNative("setup_ds18b20", pinNumber)
Timer1.Initialize("Timer1_Tick", 1000)
Timer1.Enabled = True
End Sub
Sub Stop
Timer1.Enabled = False
Log("ds18b20 stopped")
End Sub
Private Sub Timer1_Tick
RunNative("read_ds18b20",Null)
Log("ds18b20 temp=", temperature_ds18b20)
Ready_flag = True
End Sub
#if C
// Include the libraries
#include <OneWire.h>
#include <DallasTemperature.h>
OneWire* oneWire = NULL;
DallasTemperature* sensors_ds18b20 = NULL;
void setup_ds18b20 (B4R::Object* o) {
byte pin = o->toLong();
if (oneWire == NULL) {
oneWire = new OneWire(pin);
sensors_ds18b20 = new DallasTemperature(oneWire);
sensors_ds18b20->begin();
sensors_ds18b20->setResolution(12); //ADC resulution 9...12
}
}
void read_ds18b20 (B4R::Object* unused) {
if (sensors_ds18b20 != NULL) {
sensors_ds18b20->requestTemperatures();
delay(20);
b4r_esp_ds18b20::_temperature_ds18b20 = sensors_ds18b20->getTempCByIndex(0);
}
}
#End if
BTW, Adafruit_SSD1306 library can be used for temperature value displaying with the degree sign by such code:
With degree sign:
Public bc As ByteConverter
...
Dim multiLine As String = JoinStrings(Array As String(NumberFormat(esp_ds18b20.temperature_ds18b20, 1, 1), bc.StringFromBytes(Array As Byte(247))))
RunNative("SSD1306_show_line", multiLine)
RunNative("SSD1306_updatedisplay", Null)

Last edited: