Something is troubling my mind, about what is better between those both..CAN bus and I2C. I want to know the difference between those both. As some manufacturers upgrade their bus from I2C to CAN bus. I always thought I2C is better as it is simpler and can go in a high speed.
The two protocols you mention have each been created to provide solutions for two very different communications problems. So any comparisons you make between these two protocols will not help you decide which to use. It is clear that you have not done your home work/read/understood about these protocols in any depth.
The following is a small (and far from complete) list of functions/services you need to include in your review process/homework answer;
1. Fault Management
2. Data Validation
3. Error Detection
4. Band width
5. Data bus ownership.
....As some manufacturers upgrade their bus from I2C to CAN bus.
I expect this change of protocol is as a result of re-designing their products to fit the specification given to them by their client
I always thought I2C is better as it is simpler and can go in a high speed.
Is it? If high speed is your only design rule, then forget serial comms and go over to parallel comms system (think old printer port protocols).
And is it true that I2C consume less power than CAN? How can we possibbly count the power dissipation from both bus (so that we may know the ratio, it is good as a comparison).
It is your design, for a very quick check use ohms law to run the basic power dissipation math for the I2C and CAN interfaces.
Please give me some ideas with their comparison. (until know I never use CAN bus..so I don't know it from the CAN bus side). And if I have to choose from those both, what should I use? and why?
Again another home-work question. My advice is to read and try and understand both protocol specifications. Then talk to your customer/client to discover the requirements for data transfer,hardware, etc. Then go back to the protocol and see which protocol ticks the most number of boxes. Use hardware, data life, error detection, bandwidth, customer requirements as your basic review list.