Bluetooth Low Energy IOT

  Car 12V  Battery smart charger voltage logging is useful, when you want to know charged capacity and battery state of charge. Connecting this wireless logger to 12 V battery can also check real battery voltage during start, off and driving. Battery connected on 12V Smart Charger (3A , 0.8 A , 0.1A): Hardware was done with STM8S103 module and HM-10 Bluetooth Low Energy module. Charger logger schematic diagram done with KiCad: Also KiCad design files are included. KiCad 3D images shown here (did not order PCB): Prototype images including 3D printed covers: STM8S module firmware was developed with ST Visual Studio and COSMIC C compiler. Debugging interface was ST Link V2. Android apk was developed with Android Studio. Application displays battery voltage (current,maximum,minimum) and logged battery voltage (intervals: 1 second, 1 minute, 6 minutes ): KiCad project , ST Visual Studio Project and Android apk can be downloaded from GitHub: https://github.com/joukohak/chargerlog

  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

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 ...

Cheap and simple DIY bluetooth low energy digital oscilloscope made with JDY-08 BLE module and STM8S103 module and Li ION battery. Android application is developed to display oscilloscope data.  STM8S103 is 8-bit microcontroller with 1024 bytes RAM and 8 kbytes Flash memory. It stores 300 samples of 10 bit ADC data to RAM memory. Minimum sampling period is 5 us (200 kSamples/s).  ADC data is sent trough BLE lin k to Android smartphone application.  Circuit diagram

 Low Energy Solar Fridge controller DIY My target was to make very cheap and  very low energy  refridgerator controller to 12V solar system. Low energy fridge can be implemented with container type freezer with AC power and inverter (1000W) to be controlled by designed controller. Schematic diagram and PCB  Circuit diagram and printed circuit board was made with KiCad developement tool. Main components of the controller are STM8S103 (module or IC), BLE module JDY-08 and LCD display 16x2 lines. Printed circuit board as KiCad 3D: STM8S103  program was developed with ST Visual Studio Developer and COSMIC STM8 C-compiler. 3D printed case 3D printed cover using PLA filament: Android application Android application developed with Android Studio. Android phone can be used to adjust temperature setting, control inverter and display temperature / battery voltage information. Link to de...