An Open-Source platform to create digital devices and interactive objects that sense and control physical devices.
I am building a prototype for a remote controlled vessel (LoRa Marine Environmental Reconnaissance, or LoRa MER) that gathers environmental data and relays it to a shore based station using Arduino MKR WAN 1300 LoRa boards. This post is the fourth in a series, and describes the boat that will be used and a shore station for receiving data.
There was a major change this week in that the direction of the project changed from a moored buoy as a platform to a RC boat.
The following features are now active:
- RC control and motors tested on land
- MKR WAN 1300 firmware tested
- Following sensors fitted temporarily and tested
- ST3775 Display
- LoRa Messaging
- LoRa Reception
- ICP10100 Atmospheric Pressure / Temperature
- NEO-6M-0-001 GPS
- Thermistor Water Temperature
- Thermistor Air Temperature
- KX224-I2C 3 axis Accelerometer
- Enclosure completed
- TFT screen fitted
- Waiting on rubber duck antenna
- Firmware has LoRa reception (polls) and responds with RSSI
I debated on whether to build a moored buoy or to use a Radio Controlled boat to collect data. The RC boat advantages include easier investigation of multiple sites and to be honest the fun factor. A moored buoy would be less expensive, easier to make, and more seaworthy. In the end, fun factor won out. The boat selected was reasonably low cost (~$60 US) and has adequate space for the electronics. It does not appear that seaworthy however and for now will be used only in fresh water instead of the Puget Sound as originally envisioned.
In the photo below the cockpit has been removed to show the insides. The controller is shown far upper left and features forward throttle control and port / starboard steering using the twin motors - there is no rudder. The electronics have been loosely arranged in the cockpit to show how it might eventually fit. For now it is loosely placed inside the hull. Eventually it will need to be more permanently installed and holes or a sea chest made to properly expose the sensors. Fortunately all of the sensors and parts are modular and can be easily moved around and rearranged.
Preliminary tests were done indoors and the RC control and motors are functioning. The LoRa radio transmits OK from inside the hull and the sensors work. Things needs to be buttoned up and made seaworthy before tests on water are done.
A compact shore station was constructed using a weatherproof enclosure that runs off of USB power. It features a TFT screen and can be connected to a Raspberry Pi or other computer with Wi-Fi for connection to the internet. The original intent was to use LORAWAN but coverage is very poor (non-existent in my immediate area) and I decided it was better to have something more portable with the RC boat.
The antenna is sub-optimal and currently is inside the enclosure. I am looking at fitting a "rubber duck" antenna. In the photo it is showing -98 RSSI upstairs in my home with the boat down in the basement. My guess is that even with this antenna the range is going to be as good or better than the RC boat but that remains to be seen. Firmware enhancements and the internet connection still needs to be done.
- Make the boat shipshape
- Test distance on land, possibly start tests in water
- Refine shore station firmware and start looking at internet connection
- Look at addition of turbidity sensor
Comments, corrections, and ideas are always welcome!