This is short tutorial how to send data from sensor connected to The Things Network via LoRaWAN to Weather Underground. I will use Scidrom air quality sensor whic I developed for students in local school. Just a quick reminder the “AQ” sensor detects PM10, PM2,5 particles, air pressure, temperature and humidity and solar radiation in visible in UV spectrum. More details are available in older post.
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
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
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.
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.
The described device is nearly matchbox-sized board (50 x 24 mm) packed with sensors. Auxilary board is 10x50mm with additional sensors. The module is developed around the Murata ABZ LoRa module, which integrates STM32L072 and samtech SX1276 in tiny 12.5 x 11.6 x 1.76 mm package. The main board is equipped with following sensors:
There are two 1Mbit EEPROMs on-board for local data logging. Additional pins are available for SPI, 2x UART and I2C interface, where even more sensors can be attached.