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Hi,
I am looking for addressable sensors which can work on I2C, 1-wire protocol or any other similar protocols. Requirement is to connect multiple sensors(reading analog and digital data) on a single bus(upto 25 of the same kind). I cannot use i2c extenders because I want each slave address to be uniquely addressable from a master(There may be upto 25 connected as slaves). Its more like plug and play of sensors.
With some searching I was able to find one chip from Maxim which would help me do this. https://www.maximintegrated.com/en/products/interface/controllers-expanders/DS2413.html/tb_tab0. Is there are any in TI family of similar features. Because the Maxim ones help in only manipulating digital I/Os. I am looking for uniquely Addressable ADCs(again upto 25 units) also which can be plugged in to the same bus.
It will be great if someone can let me know if there is an IC in the TI family which can help me do this. Or am I better off connecting each sensors to a cheap controller and make that as a slave to the main controller?
Hello Amil,
You ask about i2C sensors, i2C ADCs, reference a Maxim i2C switch, so I'm not clear on how all this fits together. Could you provide a block diagram of what this design looks like, and how it is to operate. Do you have the sensors already selected, or is that part of the selection process? You also mentioned a uController, are you selecting those as well?
I am eager to assist with this design, I just need some more information to assist with the best selections.
~Leonard
Hi Amal,
For the i2C Analog Switch, look at the TPS22993: http://www.ti.com/product/TPS22993/description .
For processor and sample I2C code, you might look at the Tiva™ C Series LaunchPad Evaluation Board Software SW-EK-TM4C123GXL from this page: www.ti.com/tool/boostxl-senshub .
~Leonard
Amil,
You could use something such as the CD4067B 16:1 Analog MUX : www.ti.com/product/CD4067B.
Would this be an acceptable alternative? You will control this with four digital address bits from the central uC.
A block diagram of the interface bus would still be helpful.
~Leonard
Hello Amal,
If you have sensors that have the same address you can still have multiples of them in your system if you use an I2C mux/switch which allows you to toggle between devices in a polling methodology. Here is a app note that goes over some of the I2C devices, like switches. The TCA6424A can support up to 24 channels.
http://www.ti.com/lit/an/slva787/slva787.pdf
-Francis Houde
Hi guys,
Thanks for the response. Sorry for the delay in response, I was traveling.
CD4067B A mux wont work out as it increases the number of parallel wires in a bus and it wont be an automatic plug and play. I am attaching a rough block diagram for you (Apologies on the dirty handwriting :) )
Thanks for that. TCA6424A wont fit my bill as its similar to a mux and I want the bus parallel lines to be minimum. Hence a addressable slave is preferred.
Just wondering, does this have to be a wired-bus solution? This situation comes up all the time with wireless devices; as you add a device to the network, it requests an address/ID, the controller sends it a unique ID which the device then stores and uses for future communication. Would this work in this situation?
~Leonard