Interfacing two mojo boards

Projects you are planning or working on with the Mojo
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Nischal
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Joined: November 19th, 2015, 12:34 pm

Interfacing two mojo boards

Post by Nischal » November 19th, 2015, 12:46 pm

Is it possible to interface two mojo boards?
One as a master and another as a peripheral.
Also with this interface is it possible for one mojo to handle all the communication with the computer?

embmicro
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Joined: March 24th, 2013, 12:45 pm

Re: Interfacing two mojo boards

Post by embmicro » November 19th, 2015, 2:20 pm

Of course! There's nothing that would prevent this. You could use whatever protocol you wanted (SPI, UART, your own...) and then just have the two designs implement it.

The only thing is you would still need to plug each board into your computer to program it initially.

Nischal
Posts: 4
Joined: November 19th, 2015, 12:34 pm

Re: Interfacing two mojo boards

Post by Nischal » November 19th, 2015, 2:35 pm

Thank you.
I have an other question.
I am trying to drive all the pins on the mojo and it so happens that 2 particular pins are not able to drive the Chip select signals(implementing SPI)
The problem repeats even if i change the mojo board itself.
Do you know if the drive strength drops when i try to use all the IO pins

embmicro
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Re: Interfacing two mojo boards

Post by embmicro » November 24th, 2015, 1:38 pm

There is a maximum amount of current you can pull through all the pins. If I remember correctly off the top of my head it is around 24mA per bank and 100mA for the entire chip. What are you connecting the pins to?

Nischal
Posts: 4
Joined: November 19th, 2015, 12:34 pm

Re: Interfacing two mojo boards

Post by Nischal » November 24th, 2015, 1:44 pm

i am interfacing 48 LSM303D magnetic sensors mounted on PCBs.

embmicro
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Re: Interfacing two mojo boards

Post by embmicro » December 1st, 2015, 2:14 pm

You shouldn't have any trouble driving all the pins when connected to digital inputs. You'd run into trouble if you were trying to drive a ton of LEDs directly, but digital inputs take practically no current.

Have you tried measuring the pin's voltage? What behavior are you seeing?

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