Master slave

Projects General Guidance
1

Hi I'm newish to arduino, and really inexperienced so please be patient with me.

I saw on the website a page on master slave programs and was curious about it. I have an uno and a mega that my friend have me so I have 2 units. And I'm thinking of trying to make something with them.

What can I do with the master slave thing and how is it different from using just one? Like any project ideas with it?

Thanks in advance

2

Do you mean I2C master-slave? You can have a sensor connected to one Arduino and transmit the data from the sensor to a second Arduino and show the data with an LCD (also can be an I2C slave) or LEDs or ....

3

groundfungus:
Do you mean I2C master-slave? You can have a sensor connected to one Arduino and transmit the data from the sensor to a second Arduino and show the data with an LCD (also can be an I2C slave) or LEDs or ....

Yes that's what I meant I2C.
Ok, and is that required to use 2 arduinos? Or just optional? I'm trying to find something that's cool and maybe really useful, but particularly where it requires 2 with I2C. No particular reason why in just trying to learn different things by experimenting and I want to learn this next.

4

If you just want to explore how I2C works you could use a button on one Arduino to blink an LED on the other. Or use a potentiometer on one to control the angle of a servo on the other.

I2C is just a means for exchanging data between two devices.

To my mind the master and slave concept is much more useful when there are several slaves. And the master/slave concept is not restricted to I2C.

...R

5

Robin2:
To my mind the master and slave concept is much more useful when there are several slaves. And the master/slave concept is not restricted to I2C.

Ok ill look into a project like that.
What useful things did you have in mind as an example or two of several slaves?
What other methods are there? Are they better?

Thanks

6

There are many devices that communicate using I2C. Real time clocks, LCDs, accelerometrre, rate gyros, port expanders and many more. The I2C bus can control, theoreticaly, over 100 devices using only the SCL and SDA pins. Each device on the bus must have a unique address.

7

lmboyer:
What useful things did you have in mind as an example or two of several slaves?
What other methods are there? Are they better?

It 's not a case of being "better" - just different, maybe more suitable in different circumstances.

I have a master-slave system using 2.4GHz wireless transceivers to control NGauge model trains. I wrote about it here. Note that the code needs modification for the current hardware (just in case you are tempted to try it)

...R