This is a custom, machine assembled, CAN shield designed to fit the 30 pin ESP32 DevKit1 board version. It uses the SN65HVD233 CAN transceiver and can be powered directly from a 12v power source (ex: a car battery).
CAN
- Data Rates up to 1 Mbps
- Cross-wire protection
- Over temperature (thermal shutdown) protection
- EMI and ESD bus protection using NUP2105
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Power
- Max Input Voltage ( without voltage divider): 24 Volt
- Max Input Voltage ( with voltage divider): 15 Volt
- Max Input Current: 2 Amp
- Frequency: 570 kHz
- Output: 3.3V to the ESP32 board
- Overvoltage transient protection
- Thermal shutdown protection
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The red LED, voltage divider and 120Ω resistor are disabled by default and can be enabled by soldering solder-jumpers on the shield.
The SN65HVD233 CAN transceiver can be configured into 2 modes (using a physical toggle switch):
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- RW mode: The transceiver is active and the shield can Read and Write to the CAN bus. The Rs pin is connected to ground through a 10kΩ. The driver will have a slew rate of ~15 V/μs.
- R mode : The transceiver enters a low-current standby mode during which the driver is switched off and the receiver remains active. The shield can only Read from the CAN bus and is not able to write to it. Rs is connected to 3.3V.
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Wiring
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- Car’s CAN High to CAN-High
- Car’s CAN Low to CAN-Low
- Car’s Power Source to Power-12V
- Car Ground to Power-Gnd
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Schematic



Sample Code (download code)

Video overview of the original v1.0