I am currently at university, coming up with a project to measure the air pressure of a Train's pneumatic braking system. Each coach of a train has its own test point and my idea would be to install a 5V pressure transducer, linked with its own UNO WiFi board, into each of 4 coaches, with the data sent to an IoT dashboard to be picked up so that the pressure values for each of the 4 coaches can be recorded simultaneously.
I am just looking into the feasibility of such a system, as I have very little knowledge on IoT and would like to get into it (have used arduino in the past for a few projects however). Would just like to know if it is possible to link the 4 UNO boards to show on the same dashboard, or whether there is some option to do this. Thanks for any responses.
Yes it’s possible , but think about the environment , accuracy, resolution you want and look at what is commercially available for a similar task . ( you can buy for example wireless /Bluetooth transducers )
Don’t underestimate packaging and development costs !!
Really need a specification for the job
The project is more a proof of concept at the moment, to design a cheap system to see if the task can be sped up and made more accurate, compared to the current method whereby a digital test gauge is plugged into each coach one at a time and read by an engineer. The aim would be to test the theory and then go onto looking into the more expensive systems offered by RS Pro etc. and their wireless transducer system.
I will look into the Arduino UNO WiFi boards a little more then, thanks!
What is the purpose of the measuring? I can imagine several interesting aspects.
What accurazy is needed regarding time and making all boards read at reasonably the same moments.
As my nick, an old railroad active guy.
To ensure the brake pressures are within tolerance for each given braking step selected from the driving cab, which is a task carried out at given mileage intervals. Accuracy wise, for the proof of concept, this is not so essential, however, will need to measure with a resolution of at least 0.2bar, from 0bar up to 6bar.
The data collected by the transducers could also be used to look at historical trends and how the brake system performance varies overtime (more of an interesting side plan and not the main aim however).
If each train has its own internet stuff then set up a MQTT Broker or use a public broker to transfer the data. From there the data can be collected in a centralized location. The actual reason MQTT was invented for in the first place.
Can You describe how the brake system is designed?. In Europe the usual system is one manin airline going through the entire train. That line charges the car brakes during driving. For breaking the driver lowers the pressure by 0.5 to 1 bar for a comfortable braking action. The braking has to been choosen according to the available friction. In autumn, leaves on the tracks limits the available friction by a lot.
The only thing making air pressure vary from car to car is leaking air between the cars.
I won't go into much detail as is a complex system on the units my project is based upon. But basically, each coach has its own braking computer which responds to inputs from the driver's controller. The brake computer decides how much rheostatic and friction braking is required at any given speed and controls both systems accordingly. Each coach brake system is pneumatically separate from each other coach, and every coach has a different air pressure tolerance dependent on vehicle weight and whether it has motors or not to provide the rheostatic braking.
Okey. Sounds like digitally controlled brakes.
Then I can understand the need for checking each car.
The need for checking the systems at the same time, within nanoseconds, is not the case.
Is there any train Wifi available?
Anyway, there are certain distances from the last to the first car and the receiver of the messages. Some kind of radio link, Rf, looks useful.
Hi, yes each coach has its own WiFi access point so should be OK there.
My main question now is will an Arduino UNO WiFi board actually connect to the arduino cloud as from what I can tell, it's not supported. Have been looking into possibly linking the UNO up to an MKR1000 via serial link so that can send out the data to the arduino cloud. Unfortunately the MKR1000 does not supply the 5V required for my pressure transducer so cannot use that on its own I don't think.
Please post a link to the datasheet of the pressure sensor. Then we can discuss the need of current supply. Sensors are usually not that current hungry.
It will be less difficult to mak each Arduino connect to the cloud. Adding a central board receiving the 4 data from 4 Arduinos adds difficulties.
Thanks for the response, unfortunately this is the best I have for the pressure transducer I'm looking at. Has all the info but as it's such a cheap sensor, it's not a proper datasheet as such. Again, accuracy is not so crucial, but how I can get the data from 2 transducers to display on the arduino cloud simultaneously.
The Arduino cloud docs don't mention the Uno, presumably because it isn't wifi equipped. There may be a way to get it to work with a WiFi shield - worth looking perhaps.
Then again, there are plenty of other IoT providers you could try, Adafruit for example. I'd be inclined to persist with a single microprocessor per coach to avoid the complexity of having to have another processor just to talk to the cloud.
Thanks for that, just taken a look at Adafruit and looks like that could be a good solution as I have found some modified libraries online which will allow the UNO WiFi board (this board does have built in WiFi) to connect to the Adafruit IO network.
