Hi, I built a device that activates a relay depending on the difference between two temperatures measured with thermocouples connected to an ArduinoUNO board with MAX6675. (attached is a picture of the device and the code used for it)
Now I wan't to build a device that activates independent relays depending on the difference between independent pairs of temperature (T and T', Job and Sample respectively). Also, I want T to be wireless transmitted to the controller. (this would be the connection between the emitter and the receiver in the attached sketch).
I was thinking of using:
NANO boards to get T from jobSensor and send it through the emitter
MEGA board to get T through receiver, get T' from sampleSensor, activate relay depending on difference between T and T'
Are this boards adequate for the job? Is there a better option?
What do you recommend for the sensors, emitters and receivers?
Temperature Range: [0-70] degC
Max Distance between emitter and receiver: 100m
Max number of Job-Sample pairs: 5
You may wish to clarify your intended environment. 100m outdoors with clear line of sight is much different to 100m inside a factory/warehouse where there is reflection and electrical noise. Also you need to specify what your power considerations might be- is there mains power at all sites or do you need to run on battery or solar?
The actually data collection and activation seems straightforward and can probably use any arduino board.
Attached is a map of the location the receivers and the emitters, and the respective distance from the latter to the former.
The enviroment is a pre-cast concrete factory. For example, between emitter1 and receiver there would be casting moulds, piles of beams, electrically powered cranes, forklifts and labourers.
Hi,
Look at the nRF24L01 +.
It has an amplifier on it and an aerial socket and aerial.
If needed you can add coaxial lead to elevate the aerial.
For your environment you may have to purchase a couple of these units and use some simple code, possibly from the one of the examples in the libraries that are available for the nFR unit.
And place them at your locations and see what you can achieve.
I'm sure most of the libraries has a simple link test code that would help.
I'm wondering how you put images in your posts, when I click on "Insert an image" it asks me for an URL, so I'm guessing I'd have to upload it on the web and then post it.
How many bytes of data do you need each temperature? How fast will the temperatures change?
You could likely send at 9600 and be on top of tens of them all the time.
"I'm wondering how you put images in your posts, when I click on "Insert an image" it asks me for an URL, so I'm guessing I'd have to upload it on the web and then post it."
Attach the image, click post.
After the post, right click, copy the image address.
Modify the post, paste it back in using img tags.
Looking at that satellite image: making direct connections may be tricky.
Does your plant have WiFi coverage? If so that could be another way to link them together. As long as they all have WiFi connection you're good to go.
Would "chip select" be the CS connection in the MAX6675 and the CSN connection in the nRF24L01?
Would the MISO be the SO connection in the MAX6675? It seems there's no MOSI in the MAX6675.
The first stage of my project worked well with a 5V supply for both the relay and the MAX6675, and according to this post the nRF24L01 works better with 3.3v. I'm not familiar with the concept of "5V/3.3V buffering" and I don't see why would it be necessary.
My conclussion:
all the MAX6675-SO would share the same pin with the nRF24L01-MISO
all the MAX6675-SCKwould share the same pin with the nRF24L01-SCK
all the MAX6675 to 5V
the nRF24L01 to 3.3v
each MAX6675 its own pin for CS
one different pin for CSN, CE and MOSI in the nRF24L01
Am I right? Attached are pictures of all these connections.
Here is the last sketch I've made and the respective code for both the emitter (MAX6675 & nRF24L01) and the receiver (MAX6675 & nRF24L01 & Relay).
I've been reading the book "Practical Electronics for Inventors" (Paul Scherz) to get myself familiarized with the concepts involved in this project, along with several articles and posts found online. In spite of this, I'm hitting a wall with the complexity involved. I wold really appreciate if you could please check my sketch and codes and let me know if I'm on the right path. Also, I'm open for any recommended source to study.
