What is inside smart watch?

Amazfit pace went swimming and drowned 🙂 After unsuccessful warranty claim I put watch in the drawer and forget about it because it looks “unopenable”. Today I learned it could be opened easily when heated. So I decided to try it. I grabbed hot air gun and shot few blows into the housing heating up to 80°C. It is just below 85°C, which could be a limit for some electronic components.

The proper tool to open the smart watch

The disasembly was piece of cake. Just separate the two pieces.

Continue reading ‘What is inside smart watch?’ »

Toothbrush stand

I designed simple two pice toothbrush stand for 8 brushes. In our large family it is sometimes hard to track the toothbrushes only by color. I decided to put this issue in order by ordering the brushes with two simple 3D printed parts. Front one has magnets for removing from the shelf when needed due to cleaning.

Holder in place used in bathroom

Model files are in this file: STEP, PARASOLID and Solidworks

3D model with bathroom shelf

Two pieces for 3D printing

Two magnets (12mm dia, 2mm thick) are attached with epoxy into front holder. Add two more magnets and attach with epoxy to the uderside of the shelf as shown in the first picture.After curing/drying the holder can be removed and cleaned.

Rear holder is attached with two side self adhesive.

Grabcad project: https://grabcad.com/library/toothbrush-holder-8

Please share if you like the idea.

 

 

Versatile LoRa device – sensor interface

A versatile LoRa end device has been designed for connecting different sensors to LoRa network. It’s primary use can be LoRa weather station but is not limited only to enviromental applications.

LoRa sensor interface – typical application

Typical “weather” application is shown in image above: 1-LoRa sensor interface, 2-Particle sensor, 3-Sun shield with temperature and humidity sensors, 4-UV-index and illumination sensor, 5-solar panel for autonomous operation

Continue reading ‘Versatile LoRa device – sensor interface’ »

Preparing wine with IoT sensors

Every wine producer needs to know their temperature during fermentation. There are many small producers (like in our family) without high-end equipment for fermenting the grapes and must. We produce wine for our own use (around 1000 litres) and the technology relies mostly on experience and limited information about the fermentation process.  One of the most important paramters is temperature or more specifically, the temperature profile (time dependance), its gradient and maximum value as well. In the past I connected simple I2C sensor to raspberry pi and sent data to mysql database via WiFi connection. It is shame to mention the power consumption of such thermometer.

Loradunchy module on top of the low cost solar cell

Recently, I placed LoRaWAN gateway at the top of the vineyard to cover all future need for connecting winegrowing sensors in all neighbouring vineyards. The r.pi thermometer was upgraded to LoRa and I used my own design, the LoRaDunchy module with small LiPo battery, TMP75 as sensor element and small solar cell for supplying the power. Solar power is somehow overkill for this application, but I want to check the real life solar powered sensor. It would be good experience for future sensors which I intend to place in the field for monitoring the microclimatic conditions (and possible prediction of the vine diseases).

LoraDunchy Connection diagram for thermometer application

Continue reading ‘Preparing wine with IoT sensors’ »

Particle Sensor with LoRa

Two PCBs from earlier projects were used in this project:

  1. LoRa breakout board
  2. Sensor PCB with Si7013 humidity sensor from multisensor LoRa project
  3. … and particle sensor.

 

Finished particle sensor in housing, ready for the TTN

Continue reading ‘Particle Sensor with LoRa’ »

Small “rubber-ducky” helical antenna for 868MHz

This simple Helical Antenna can be used for most LoRa (and other small wireless device) applications, where space constraints exist. The construction is simple, made from wound solid Ag plated copper wire taken from piece of coaxial cable.

Helical axial antenna for 868MHz

Two options how to use this antenna on the PCB modules

Continue reading ‘Small “rubber-ducky” helical antenna for 868MHz’ »

LoraDunchy Arduino Nano pin-compatibile LoRa module with power management

Lora board with Arduino nano compatibile pinout and simple battery management

Small board with arduino nano compatibile pinout with power management and Murata ABZ LoRa module with STM32L0 microcontroller

Features

  • LoRa module: Murata ABZ
  • Single cell LiPo cell charger on-board with charging signal internally connected to PA11 (via jumper)
  • Buck/Boost switching power supply for delivering stable 3,3V regardless of the batterz voltage
  • Battery fuel gauge on-board to control the real status of the battery

 

Schematic diagram

Continue reading ‘LoraDunchy Arduino Nano pin-compatibile LoRa module with power management’ »

Protected: Power and safety controller for robots

This content is password protected. To view it please enter your password below:

RAK811 3D model and plastic housing

There was no3D model for RAK811 breakout board with GPS tracker, so I made it from the drawings. I added plastic housing to be used with velcro straps. I prepared two models, one with only RAK811 and small LiPo battery and second one, 4mm higher with enough space for additional PCB with custom electronics. Enjoy.

Higher version with additional PCB

Lower version without additional PCB

Base is same for both versions.

Continue reading ‘RAK811 3D model and plastic housing’ »

LoRa module in DIL form

Murata produces LoRa module CMWX1ZZABZ-xxx based on SX1276 transceiver and STM32L072CZ microcontroller. The soldering of the LGA module is not very hobby-friendly. I constructed small breakout PCB for this module with additional buck/boost switcher and place for SMA connector. The transceiver features the LoRa®long-range modem, providing ultra-long-range spread spectrum communication and high interference immunity, minimizing current consumption. Since CMWX1ZZABZ-091 is an “open” module, it is possible to access all STM32L072 peripherals such as ADC, 16-bit timer, LP-UART, I2C, SPI and USB 2.0 FS (supporting BCD and LPM), which are not used internally by SX1276.

LoRa breakout board

 

Continue reading ‘LoRa module in DIL form’ »