quinzyamg
Posts: 5
Joined: Wed May 22, 2019 7:16 am

Arduino connection to the PI (with 12C)

Wed May 22, 2019 7:20 am

Is there a way to connect an Arduino to the pi besides the usb connection. I know you can connect it using the TDX and the RDX pins but the issue is that my gsm add-in already use these pins, can i connect the arduino to different GPIO ports to still get the same data transfer capabilities or is there just no way apart from using either the above mentioned pins or a USB cable.


quinzyamg
Posts: 5
Joined: Wed May 22, 2019 7:16 am

Re: Arduino connection to the PI

Wed May 22, 2019 10:28 am

Thank you dude, you're a life saver!

quinzyamg
Posts: 5
Joined: Wed May 22, 2019 7:16 am

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 8:56 am

I know my question was answered in the above part of the post, but i seem to have run into a new problem, my data transfer rate is very intermittent. At first i thought it was due to me not having a logic level shifter connected, but for some reason with the shifter connected i get no i2c detection from the pi's side. What could be the problem.

Brandon92
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Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 9:07 am

Did you connect the level shifter in the right direction? A picture could help also.

quinzyamg
Posts: 5
Joined: Wed May 22, 2019 7:16 am

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 9:13 am

I think so. the picture attached is the exact same Shifter i used. I put the HV on the Arduino's side and the LV on the pi's side. i Also measured the voltages on both sides and on the Pi it reads 3.3V and on the Arduino it's 4.8V.

Also a link to where i bough it:
https://www.robotics.org.za/BOB-12009
Attachments
20190524_105256(2).jpg
20190524_105256(2).jpg (54.91 KiB) Viewed 1380 times
BOB-12009-000-650x350.jpg
BOB-12009-000-650x350.jpg (43.94 KiB) Viewed 1383 times

Brandon92
Posts: 769
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 9:29 am

You have forgotten to connect the 3,3v and 5v to the level converter. Like the schematic in the link you posted.

quinzyamg
Posts: 5
Joined: Wed May 22, 2019 7:16 am

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 9:34 am

I left the 3.3v and 5v off, since i still power the arduino via the usb. Is it still necessary to connect the power for both even if both are separately powered?

Brandon92
Posts: 769
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: Arduino connection to the PI (with 12C)

Fri May 24, 2019 9:43 am

Both voltages need to go to the level shifter, otherwise the level shifter will not work.

Edit:
The voltages are used to provide power to the level shifter itself. Without that connected it will not work properly. I could give you a detailed explanation why.

alphanumeric
Posts: 1714
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Arduino connection to the PI (with 12C)

Mon May 27, 2019 12:21 pm

What he said, I have this one, https://www.adafruit.com/product/757 It won't work unless you power the 5V and 3.3V inputs.
If your wanting high speed you may be better off with something like this, https://www.adafruit.com/product/395

alphanumeric
Posts: 1714
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Arduino connection to the PI (with 12C)

Mon May 27, 2019 12:22 pm

What Arduino do you have? I ask because some use 5V logic and some use 3V logic. You may not even need the level shifter?

gordon77
Posts: 3887
Joined: Sun Aug 05, 2012 3:12 pm

Re: Arduino connection to the PI (with 12C)

Mon May 27, 2019 6:42 pm

alphanumeric wrote:
Mon May 27, 2019 12:22 pm
What Arduino do you have? I ask because some use 5V logic and some use 3V logic. You may not even need the level shifter?
The OP said...
i Also measured the voltages on both sides and on the Pi it reads 3.3V and on the Arduino it's 4.8V.

alphanumeric
Posts: 1714
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: Arduino connection to the PI (with 12C)

Mon May 27, 2019 7:23 pm

gordon77 wrote:
Mon May 27, 2019 6:42 pm
alphanumeric wrote:
Mon May 27, 2019 12:22 pm
What Arduino do you have? I ask because some use 5V logic and some use 3V logic. You may not even need the level shifter?
The OP said...
i Also measured the voltages on both sides and on the Pi it reads 3.3V and on the Arduino it's 4.8V.
I saw that, just not 100% sure where they measured it? If it was on the level shifter it may be because its shifting it to 5V?
Can't hurt to know what Arduino they are using.

mindsacred
Posts: 2
Joined: Tue Mar 19, 2019 6:01 am

Re: Arduino connection to the PI (with 12C)

Sat Jun 15, 2019 6:18 am

Brandon92 wrote:
Fri May 24, 2019 9:43 am
Both voltages need to go to the level shifter, otherwise the level shifter will not work.

Edit:
The voltages are used to provide power to the level shifter itself. Without that connected it will not work properly. I could give you a detailed explanation why.
Hi!

Can you explain me pls?

Brandon92
Posts: 769
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: Arduino connection to the PI (with 12C)

Sun Jun 16, 2019 6:15 pm

mindsacred wrote:
Sat Jun 15, 2019 6:18 am
Brandon92 wrote:
Fri May 24, 2019 9:43 am
Both voltages need to go to the level shifter, otherwise the level shifter will not work.

Edit:
The voltages are used to provide power to the level shifter itself. Without that connected it will not work properly. I could give you a detailed explanation why.
Hi!

Can you explain me pls?
What do you want to be explained precisely?

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