Bluetooth Low Energy 12V Car Battery Voltage Logger

 If you are unsure about your car battery and charger capacity, you can use this diy battery logger in 12V plugin connector to measure it.

For this logger I used STM8S103 module and HM-10 Bluetooth Low Energy module and Android Smartphone as displaying device.

STM8S103 bluepill module:

HM-10 BLE module

Android application screenshot:

Hardware schematic diagram drawn with KiCad:

STM8S103 Firmware was developed with ST Visual Studio with COSMIC C compiler in Windows PC.  ST Link V2 as programming /debugging interface.

Kicad 3D images of project hardware:

And actual prototype images:

Android application screenshots of battery voltage logging:

Project files  for KiCad , ST Visual Studio and Android apk to download:

https://github.com/joukohak/batlog

STM8S Bluetooth Low Energy oscilloscope

Simple and cheap DIY oscilloscope can be done with STM8S103 module and HM-10 Bluetooth Low Energy module using Android smartphone as display.

   STM8S103 module:

JDY-08 BLE module need HM-10 version 709 firmware and set up to 9600 baud UART mode.

Firmware can be programmed to  with TI CC debugger.

https://www.ti.com/lit/ug/swru197h/swru197h.pdf?ts=1736391991950

More info ,how to do:

https://www.iot-experiments.com/jdy-08/

Oscilloscope schematic drawn with Kicad:

STM8S  firmware was developed using ST Microelectronics Visual Studio (Windows) using free license COSMIC compiler and ST Link V2 for program and debug interface.

This 1 channel 200 kS / 5 us oscilloscope  is battery powered (usb charging).

Including following features:

  - 1 channel 5us ... 5ms period 240 samples

  - max , min voltage display

  - AUTO / SINGLE  trigger

  - AC/DC select

  - LV / HV (high voltage 400V probe needed) attenuator select

  - sine wave generator

  - rising/falling trigger

  - Automatic power off

Hardware prototype with 3D printed custom covers:

Android application was developed with Android Studio.

Here are some screen captures about application:

High Voltage Sine measure:

Modified Sine Wave inverter output measure:

Project files for Kicad , ST Visual Studio and Android app can be downloaded from:

https://github.com/joukohak/digitalscope

BluePill (STM32) BLE oscilloscope

 Bluetooth Low Energy wireless interface can be used to transfer measurement data to Android smartphone.  My simple digital oscilloscope is done with 

 STM32F103C8T6 Core Board Development Board Bluepill

and Bluetooth low energy module  HM-10 :

Kicad drawn schematic diagram for this bluetooth low energy oscilloscope :

Designed also PCB in Kicad and was able to show these 3D images:

Kicad project is included in GitHub repository:

https://github.com/joukohak/stm32_blescope

Repository also includes  STM32 CubeIDE project  and  Android  apk.

Implemented hardware and 3D printed cover like this:

STM32 firmware was developed in Linux Mint PC with STM32 CubeIDE developement application and interface was ST Link V2:

Android application was developed with Android Studio.

Some screen captures of Android application:

Features include:

- AUTO triggering

- Single trigger

- START trigger rising/falling trigger level setting on channel 1

- 2 channel 1000 samples with period setting from 0.5us to 15ms (2MSps to 16.7 Sps).

- AC/DC select

- sine/triangle wave generator

- Max/Min / trigger Voltage display