Timeline for Why do microcontrollers always need external CAN tranceiver?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Mar 14 at 8:58 | comment | added | Robin | I always thought CAN was a development from RS-485. Its almost RS-485 with arbitration free bus contention, a CRC-15 and the final ACK bit to make sure your message was actually heard. The bus off when the error counters mature (which are like leaky buckets more than counters) is a nice final touch. | |
| Jul 25, 2023 at 16:01 | vote | accept | yeuop | ||
| Jun 28, 2023 at 17:26 | history | edited | Tim Williams | CC BY-SA 4.0 |
Added additional information from comments
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| Jun 28, 2023 at 14:20 | comment | added | Urausgeruhtkin | +1 for pointing out the economics: the whole point of general-purpose microcontrollers, as opposed to application-specific integrated circuits, is to be used in a wider variety of applications, which necessarily means economic tradeoffs. | |
| Jun 28, 2023 at 13:26 | comment | added | TooTea | Another point you did not cover is that with a bus like CAN connecting separate devices in a potentially nasty environment, one will often want galvanic isolation, which is both something that's easily done on the logic-level TX/RX signals and something not easily built directly into the MCU. (For Ethernet, this is mostly handled by the magnetics.) | |
| Jun 27, 2023 at 20:36 | comment | added | Tim Williams | @12431234123412341234123 also a good point. It's... not too big a deal, it's only two pins -- well, two pins per interface anyway; many devices with USB have it on dedicated pins as well, though usually only the one port, so there is that. | |
| Jun 27, 2023 at 9:11 | comment | added | 12431234123412341234123 | If you integrate a CAN transiver into the die, you probably can't use this pins for anything else. With CAN RX and TX you can multiplex it and use the pins for something else when the application doesn't need CAN. | |
| Jun 26, 2023 at 23:45 | history | answered | Tim Williams | CC BY-SA 4.0 |