In first thanks for your work ! its really fine!

I want use digital ports of grovepi for connect grove relays.

But how have more of digital port ? can we connect this card with grovepi ?:

If we can, how connect the 2 cards ? i2c port ? uart ? serial ? and how change the program for grovepi after that ?
i want in a same have :

import grovepi
import (what we need)
relay = 4
relay = (board2)4
its possible ? or there is an other board to coupling with grovepi for have much more digital ports ?

Sorry for my english. thanks !


I don’t think that you can connect the Mega shield with the GrovePi. What you can do is get another GrovePi. We are coming up with a new firmware and software in a few days that should let you to use multiple GrovePi’s .

We’ll keep you posted about it.



Ok thanks for your answer :slight_smile:
i need at least 28 digital out port.
With your new firmware, do you think that i can connect 4 grovepi boards ?

and the most important : can you in the same, have 1 relay of every boards ? like this :

import time
import grovepi
relay1 = 4
relay2 = (grovepi2 = 4) // or something else ?
While true: Try:

If its possible : Thaks you Very Much! your work is wonderfull ! ( now it is already a good work but with 4 grovepi its 4x more wonderfull :).


I haven’t tested it with 4 boards, but yeah it should work with 4 boards and yes you should be able to access all the boards from one program too.



Good job guys ! i wait the firmware ! i just buyed 3 grovepi more ^^ Do you think that you can do the firmware for 4 grovepi? Or you do for 2 and i must edit this with your help for change it ? :slight_smile: Or the firmware can already support more than 4 grovepi ?

If i plug 4 grovepi on one raspberry pi b+ or raspberry pi2, Do you think that i must to change the alim supply cable or its ok ?( if i have 4x7 28 relays)

Sorry for all this questions but i like this card and this forum give me a lot of answer and your reply are fast ! thanks !


4x stacked GrovePi’s? Woah.

Seeed needs to create an I2C relay, then you could just add an I2C hub or four.

My understanding with the firmware is that each GrovePi sits on the I2C bus, and as long as they have unique addresses, you should be able to stack lots of them, presuming you have a good power source.

To flash new firmware, I believe you would need to stack one at a time, as it uses SPI.


Regarding stacking, may i ask if is it possible to stack a Pi-LITEr on top of grovepi?


Hi pippi,
You should be able to use the Pi-LITEr with the GrovePi without any problems.



You can use multiple GrovePi’s together with the Pi. Follow the tutorial here: and that should set you up to use multiple GrovePi’s.

Do let us know how it goes.