Here is the receiver, designed to be fully portable - the handy device.
The purpose of it is to pick up the signal from the model device and provide the full information to the user: where to go and how far from you is the lost model.
I need to say that it works really good, tested in the city, among the buildings, with the model in the gras and the receiver in my hand I was able to pick up the signal from the distance of 490m. When no bigger buildings in between, the achieved distance was about 700m with the transmitter (model) in the grass on the ground.
The reciver is made with the TTGO ESP32 LORA868 board, there is OLED and lipol circuit - very handy. The receiver has it's own GPS module (some older, separated ublox 8, set with NMEA 115200 baud communication). So the reciver knows where it is,it picks up the signal with GPS o fthe module, so it calculates the distance and the direction to the model and it shows all this information on the OLED - simple solution.
The whole PCB together with the 380mAh lipo is put into printed housing, on top of the housing is also the GPS. Later on I have printed the additional handle, which at the end is glued to the housing - simple.
The receiver can be also connected via USB to the power bank - giving many hours of the operational time.
The receiver does not require any soldering, only conectin of the lipol and the TX signal of the GPS module connected to the pin 25. GPS shall be configured to work with NMEA and 115.2kbaud - google it how to do this.
After flashing using Arduino - works without the problem if properly made.
The informations on OLED are (from top left):
- LAT/LON of the model received,
- satelites visible by GPS in model,
- HDOP of GPS in model,
- battery voltage of the model's device,
- RSSI of received message from the model,
- working time since power up for the unit in the model,
- LAT/LON of the reciver (in hands),
- satelites of the receiver,
- HDOP of the receiver,
- time from the last message recived (shall be each 2 minutes),
- and within the rectangle: distance to the model and the direction to the model where north is 0 degrees,
The transmitter which is mounted onto the model is described here:
Both SW works and are already tested - providing very usefull system for tracking the lost model. (Hopefully it will be never uesed to this :-))
Enjoy at your own risk.