Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Microprocessor control => Topic started by: Mr.R.Duino on November 19, 2016, 11:47:50 am
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Thermal protection
There are times when it would be good to have some thermal monitoring and protection in a model boat.
It is possible to monitor the temperature of individual components in a model (motor, ESC, battery, steam boiler etc.) with a sensor(s).
The sensor in this example is a Digital Temperature Sensor - DS18B20
This sensor is a remarkable device about the size of a normal transistor, it’s quite accurate and multiple sensors can used as each sensor has it’s own unique ID.
You can use just 2 wires to simply connect the sensors in a daisy chain as the sensors can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply ( 3rd wire).
The sensors can be purchased for £3 each from Hobbytronics http://www.hobbytronics.co.uk/ds18b20-temperature-sensor?keyword=-%20DS18B20 (http://www.hobbytronics.co.uk/ds18b20-temperature-sensor?keyword=-%20DS18B20)
But sensing temperature is only half the story, we need to be able trigger an “alarm event” when predefined temperatures are reached.
To add this intelligence I am using an Arduino Uno (a clone is approx. £8)
These alarm events could be in the form of:
- an audible sound
- a flashing led
- throttle channel is restricted or turned off
- switching something on or off – this could be a relay, a fan etc.
- a combination of the above
This video will give you an idea of what’s possible and how it works
https://www.youtube.com/watch?v=amrz1m0JzQ0 (https://www.youtube.com/watch?v=amrz1m0JzQ0)
Video info:
The video shows monitoring 8 sensors and their corresponding temperatures are shown on the LCD display and their status is indicated by the RGB coloured leds. (green=ok, amber = warning, red = alarm status)
The trigger temperatures on the first sensor (top left) are green <20, amber >21 and < 22 and red >22 degrees. The servo is also moved to 3 different points according to trigger temperature
The video starts with the temperature of Sensor 1 (S1:) at less than 20 degrees. I touch it and the temperature soon goes up, first triggering the "Amber" state and then the "Red" state.
The cost for the solution - 1 sensor and Arduino clone less than £12! (excludes cabling, LCD and LEDs)
Have fun!
Mr.R.Duino
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Interesting article and could be really useful for boats running smokers or other heat producing running gear - even monitoring brushless motors which can run very hot.