14 Apr, 2021
While the components used have not changed the PCB design has seen drastic improvements. Size has been massively reduced by utilizing pogo pins combined with a Molex 13.56 MHz adhesive antenna added to the case. In addition the low profile ublox CAM-M8C replaces bigger SAM-M8Q GNSS receiver. All improvements combined lead to a feature packed 3.5 cm by 4.5 cm PCB size.
Have a look at the new images and a new demo video showcasing the unsurv-offline companion. You can also see the companion android app exchanging data via NFC and visualizing what unsurv offline has logged throughout the day.
Here are the currently used main components again:
- ESP32 WROOM
- MPU6050 for motion sensitive power saving modes
- low profile ublox CAM-M8C GNSS receiver
- a Texas Instruments RF430CL330H NFC Transponder + 13.56 MHz Molex adhesive antenna embedded into the case
- a SD-Card reader
- a standard lithium battery with onboard charging via micro USB
I am also planning to add a alarm function to the PCB either via a vibration motor or a small speaker to inform the user in special circumstances.
You can follow the development and have a look at the hardware design on GitHub.