MCU. - Circuit schematic like in figure 1 below is Circuit Schematic CAN to USB Interface NUC140LC1 Flash Memory. This is started out from a need to build a simple device for monitoring the CAN bus. Main system is the NUC140LC1CN 32K Cortex-M0 microprocessor from Nuvoton for major reason - it has both USB and CAN peripherals.
|Figure 1. Schematic CAN to USB Interface NUC140LC1 Flash Memory|
To enable the NUC140 CAN peripheral to communicate with CAN bus a CAN transceiver is required. The TJA1051T chip from NXP solves the purpose. The NUC140 device is capable operating from 5V power supply, there is no need for additional 3.3V voltage regulator. This handy combination makes a simple task implementing the CAN bus interface. There are three status LEDs:
- D1 is the status of USB connectivity to the host
- D2 shows the CAN bus activity
- D3 indicates CAN errors
The NUC140 doesn't have built-in bootloader and the only way to program it is using ARM Serial Wire Debug (SWD) interface (J2 connector) and Nuvoton ICP programmer. And yes, if bootloader is already pre-programmed it could be activated. That is the purpose of JP1 jumper. Connecting the JP1 before powering the interface will trigger the bootloader.
The Original Project : "CAN to USB Interface"