Microcontroller (SPI) --> MCP2515
MCP2515.TX --> MCP2551.TXD
MCP2515.RX --> MCP2551.RXD
MCP2551.CANH ---> 120R ---> CAN Bus Line H
MCP2551.CANL ---> 120R ---> CAN Bus Line L
| Parameter | Expected | Simulated (Proteus) | |--------------------------|----------------|----------------------| | CANH dominant voltage | ~3.5V | 3.48V | | CANL dominant voltage | ~1.5V | 1.52V | | CANH recessive voltage | ~2.5V | 2.50V | | CANL recessive voltage | ~2.5V | 2.50V | | Differential output | 2.0V (dominant) | 1.96V | | Propagation delay (TXD→bus) | < 50 ns | ~60 ns (acceptable) |
Waveform screenshot (insert simulated graph showing TXD, CANH, CANL, RXD) mcp2551 library proteus
If the goal is PCB layout rather than firmware simulation: Microcontroller (SPI) --> MCP2515 MCP2515
This is where most simulations fail.
If you are probing the CANH and CANL lines and seeing a static high voltage, it usually means the bus is in an idle state, or the microcontroller hasn't successfully initialized the CAN module. Check your CANInit() functions in your code. | Parameter | Expected | Simulated (Proteus) |
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