At year 2015 I got an idea to make a remote ( wireless) temperature device.
I used a cheap bluetooth module HC-06 and microprocessor PIC16F886-SO.
The power supply is 5V micro USB module (20-30mA).
Here is the schematic diagram
LD117V33 or L78L33 regulates the power to 3.3V
L2 is blinking when the device is not connected to other (PC) bluetooth device.
It is lighting continously when bluetooth is connected.
DS1820 is just Maxim device
There are two 3.3V regulators, only one is needed.
I made a RS232-receiver software for the PC.
I can set how often the device will save and what is the serial port.
I normally use 60 or 120s file save time. I calculate mean of temperature of 120s.
It also shows how many data is saved in this session.
There is a calibration window in the program.
You can select bluetooth com-port, calibration, and new name for the file.
Normally it put yyyymm.log i.e. 201601.log.
I saves the data for the graphics software.
Here is the file saved by PC program

Pekka OH3GDO





