Serial & I2C


#1

I’m just a newbie. I was able to get the Arduberry to communicate with the RPi with the samples you gave; thanks and I like the Arduberry.
Is it possible for me to use the serial pins for a 4DSystems touch screen and/or the I2C pins for a LCD display on the Arduberry while it’s attached to the RPi?
Thanks.


#2

Hi,
Can you give us more details about the display that you want to use and how you want to use it. There are two ways to use it: one with it interfaced to the Arduberry and other directly to the RaspberryPi.

You can use it with Serial, I2C and SPI both on the Raspberry Pi as well as the Arduino. You might have to modify either the settings on the Raspberry Pi or the Arduberry depending on how you are using it.

-Karan


#3

Hi Karan,
Thanks for responding. The first display is touch screen (http://www.4dsystems.com.au/product/uLCD_43/) is serial and can be run from either the RPi or an Arduino using 5V, Gnd, Rx and Tx pins. The second display is a LCD 20x4 character display (http://www.ebay.ca/itm/271563118446?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) and uses 5V, Gnd, SCA and SCL pins. I operate them both from an Arduino now and would like to be able to operate them from the Arduberry and. hopefully, use software serical to have the Arduberry talk to the RPi so I can use the RPi as a webserver displaying some of the data being shown on the displays. I’ve included a couple photos of the existing setup.
Thanks for your help.
Grant


#4

Hi,
You should be able to use both of them with the Arduberry. Let us know if you face any problems.

-Karan


#5

Hi Karan,
I have both the LCD and touchscreen working well on the Arduberry (the LCD through SDA/SCL and touchscreen through Rx/Tx). I’d like to also send data from the Arduberry to the RPi through software serial. I have that working through Bluetooth (sending from the Arduino, receiving through the RPi) but I’m thinking there must be a way to do that directly through common pins. I’ve been Googling but haven’t found the right help yet. Is it possible to send from the Arduino using software serial to the RPi using some of the common pins?
Thanks.
Grant


#6

Hey Grant,
Only the I2C, SPI and Serial pins are connected between the Raspberry Pi and since you are already using the Serial, you cannot use it. But you can use the I2C and it should be easy too. Here is a good example that should get you started with I2C: http://blog.oscarliang.net/raspberry-pi-arduino-connected-i2c/ .

Let us know how it goes.

-Karan


#7

Thanks Karan,
My LCD is the type that uses I2C, so that avenue is already used.
I’ll give it some more thought and see if there’s another way to handle this.
Thanks again.
Grant


#8

Hey Grant,
With I2C you can connect upto 127 devices on the same line as long as they don’t share the same address. Use i2cdetect -y 1 to find the address of your LCD from the Raspberry Pi and use any other address for communicating with the Arduberry.

-Karan


#9

Karan,
Super! I had forgotten that I2C could be used for two way communication with multiple devices (even though the example you pointed to explained that :-/).
I’ve got the Arduberry and RPi communicating over I2C; now to add back the LCD.
Thanks again.
Grant


#10

Hey Grant, glad to hear we could help out. Thank us by sharing your project when you’re done! We want to see it!