Hi all,
I just got some 16x2 display w/ shield kits. They are working nicely. I would like to daisy chain them and drive them from a single Pi. The MCP23017 controller has three address lines, so I guess I could chain up to 8 displays on the i2c bus. Is that right? Any way I can hack the PCB to set different addresses? Sure, I could put it on an external board, solder some leads to the PCB and do as I please, but I quite like the format of the display attached to the PCB.
Any advice or suggestions? Can I drive 8 16x2 displays through i2c from a single Raspberry Pi?
Thanks!
Paul
16x2 LCD display i2c - More than one?
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Re: 16x2 LCD display i2c - More than one?
With a little address hacking, you should be able to drive 8 boards on the same I2C bus.
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Re: 16x2 LCD display i2c - More than one?
Thanks for the answer.
So can I hack the Pi Plate to do this, or do I have to bring the MCP23017 to an outside board and do the address hacking there? I see three tabs in the back of the board. Are these the address lines?
Please advise!
Paul
So can I hack the Pi Plate to do this, or do I have to bring the MCP23017 to an outside board and do the address hacking there? I see three tabs in the back of the board. Are these the address lines?
Please advise!
Paul
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Re: 16x2 LCD display i2c - More than one?
I don't have one on hand to verify, but it looks like those pads are adjacent to the address pins on the chip. I'll check further to confirm.
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Re: 16x2 LCD display i2c - More than one?
Those are address pins and you can cut the trace on the middle pads on one side to ground and then solder the middle pads to t he other side to adjust the address. however, its not supported and we dont have any tutorials on it, just something we tossed onto the PCBs for fun
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Re: 16x2 LCD display i2c - More than one?
Just as I thought. Thanks! Will have fun!
Can you draw me up where I have to cut the trace and where to solder?
Paul
Can you draw me up where I have to cut the trace and where to solder?
Paul
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Re: 16x2 LCD display i2c - More than one?
If you look closely: for each set of three pads, the middle pad will be connected to one of the others. Cut the connecting trace, and use a drop of solder to bridge to the pad on the other side.
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Re: 16x2 LCD display i2c - More than one?
Got it. I guess the eyes aren't what they used to be <puts glasses on>.
Thanks for your help, sonny!
Thanks for your help, sonny!
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Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/
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