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Currently in my system we use 16 I/O expanders with I2C interface. I want to change it to CAN interface. Which is the best possible way without compromising the cost? I tried searching for 16I/O expanders with CAN interface but the maximum I could get is 8I/O. Are there any CAN to I2C converters, If yes I can use the same I/O expanders, just put a converter before.

Also looking for ADC with CAN interface!

Please help. Thanks in advance

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Which is the best possible way without compromising the cost?

Your cost will go up, if you want to replace I2C with CAN. An I/O expander with CAN interface is "simply" a microcontroller with a CAN interface. A bridge between CAN and I2C is also a microcontroller with a CAN interface. So, you are looking at a cost of a CAN bus driver IC, cost of a microcontroller itself (maybe with a crystal), labor cost of programming that microcontroller.

As a side benefit, you get some processing power at the periphery, and other goodies which come on microcontrollers.

p.s. I understand why replacing I2C with CAN may be a right idea.

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  • \$\begingroup\$ I understand the cost will go up. But are there any 16 I/O expanders with CAN interface in market? Also is ADC's with CAN interface available? \$\endgroup\$ – Ashok Apr 26 at 7:02
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    \$\begingroup\$ A microcontroller with CAN interface and 16x GPIO is your I/O expander. Same with ADC. Microcontrollers with CAN, 16x GPIO, ADC are on the market alright. You are unlikely to find canned [pun semi-intended] or hard-wired CAN I/O expanders or ADCs on the market, because different industries run different network protocols, on top of CAN physical layer. Such network protocols are a lot more varied than I2C. [If you find canned devices like that, those are exceptions.] \$\endgroup\$ – Nick Alexeev Apr 26 at 7:15
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    \$\begingroup\$ @Ashok The key is that CAN is intended for relatively long ranges in rugged environments, while I/O expanders with I2C are intended for on-board or short range communication in "nice" environments. So none make expander IC for CAN because there's likely not much of a market for it. You can find plenty of higher level DIN rail I/O stuff using CANopen though, complete with supply and output drivers. So this is probably where you need to step back and look at the bigger picture - what is your product supposed to do and what's the requirements. \$\endgroup\$ – Lundin Apr 26 at 7:43
  • \$\begingroup\$ That's correct! Is it possible for a CAN to I2C converter IC so that I2C enabled expanders and ADC can be used, which is readily available also. \$\endgroup\$ – Ashok Apr 26 at 8:45

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