Can this be used as I2C Master?

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sbonkosk
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Can this be used as I2C Master?

Post by sbonkosk » Mon Sep 03, 2018 12:27 pm

I'm starting to learn about I2C, and as I understand it there needs to be a master involved in the chain to provide the clock signal.

I wanted to know, can this bluetooth module be used as a master device?

https://www.sparkfun.com/products/14840

My thought is to connect other sensors to it and transmit the data to a phone, but that would mean this would need to be a I2C master device, right?

jremington
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Re: Can this be used as I2C Master?

Post by jremington » Mon Sep 03, 2018 1:24 pm

In this case the Bluetooth is a slave and I2C (instead of the UART) is used by a processor to send and receive Bluetooth transmissions.

You also need a processor to read a sensor, format and send the data to the Bluetooth module.

sbonkosk
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Re: Can this be used as I2C Master?

Post by sbonkosk » Tue Sep 04, 2018 8:35 am

jremington wrote:
Mon Sep 03, 2018 1:24 pm
In this case the Bluetooth is a slave and I2C (instead of the UART) is used by a processor to send and receive Bluetooth transmissions.

You also need a processor to read a sensor, format and send the data to the Bluetooth module.
Got it, thank you! So it doesn't seem like there's any options for a bluetooth board like this that are a I2C master device, everything I see either doesn't support I2C or its a slave like this one. It would be great to find a board that didnt require a processor to function and instead can be used by itself with sensors, and have the phone basically act as the processor. I figure there has to be some, where could I find something like that?

jremington
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Re: Can this be used as I2C Master?

Post by jremington » Tue Sep 04, 2018 5:39 pm

I figure there has to be some
Why? Processors are dirt cheap. Even a six pin PIC10F200 processor can do everything that is required to handle a typical dumb sensor, for $0.31.

So why should the sensor be smart? Furthermore, if your design requirements change, standard processors are reprogrammable in place, using mature, standard, freely available development software.

Perhaps you are looking in the wrong place. There are bluetooth modules with built in Arduino compatible processors, for example.

n1ist
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Re: Can this be used as I2C Master?

Post by n1ist » Thu Sep 06, 2018 5:01 am

You can always use a SOC that has both a radio and Bluetooth (nRF52832, EFR32 or ESP32 comes to mind) but that will be much more work than a small micro that acts as an i2c master.
/mike

jacquelbot
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Re: Can this be used as I2C Master?

Post by jacquelbot » Tue Nov 06, 2018 10:47 am

How about this Sparkfun board: https://www.sparkfun.com/products/13990
Processor + bluetooth (+WiFi & NFC if that's of interest to you) and it's got two I2C ports to talk to your sensor AND it's cheaper than the bluetooth module you linked above.

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