Chronodot with 4-Digit 7-Segment Display

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ilovetofu
 
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Chronodot with 4-Digit 7-Segment Display

Post by ilovetofu »

I purchased a ChronoDot and 4-Digit 7-Segment Display so that I can display the time for a project. Both are I2C devices.
The Display is connected to the A4 and A5 pins on my Arduino UNO.
However, A4 and A5 are also where I am supposed to attach the SDA and SCL respectively for the ChronoDot RTC.
How do I wire up my breadboard for this? I have studied the I2C protocol and have the understanding that I can connect multiple slaves.

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marke3
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by marke3 »

That's right. The same two pins. Each I2C device has its own address so can use the same bus. You'll see the addresses in the example code.

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ilovetofu
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by ilovetofu »

Thanks marke3, works like a charm.

I don't think the 4-Digit 7-Segment display has an address select pin, so I gather the slave address is pre-set. What would I do if I wanted to add 3 of these displays onto my breadboard to work with the Arduino?

Also, when reading the I2C specs and the ChronoDot info, they advise using pull-up resistors with the ChronoDot IF your controller doesn't already implement them. At the moment I have not added any resistors to the circuit. Should I be adding them in the case of Arduino Uno?

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marke3
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by marke3 »

The display backpack has some pads for solder jumpers to set alternate addresses and that would let you do multiple displays. Instructions here: https://learn.adafruit.com/adafruit-led ... 2c-address

I'm pretty sure all Adafruit boards, including that backpack, include the pull-up resistors so using the chronodot with the Adafruit display backpack will have you covered as they will act on the same shared data and clock lines.

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ilovetofu
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by ilovetofu »

thanks for the link marke3, that seems pretty straightforward.

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brennerh
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by brennerh »

do you know how to code the 7 segment display for an RTC chip?

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marke3
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by marke3 »

Which parts do you have? The tutorials for those should have lots of guidance.

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ilovetofu
 
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Re: Chronodot with 4-Digit 7-Segment Display

Post by ilovetofu »

marke3: yes thanks for the link, I can see how to change the address now.
brennerh: yes, I managed to initialise the RTC, read the date/time and display the time to the 7-seg display.
thanks guys for your help and guidance :)

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