2020-04-09 04:40:57 -04:00
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| Supported Targets | ESP32 |
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| ----------------- | ----- |
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2017-12-18 07:32:29 -05:00
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# CAN Alert and Recovery Example
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## Overview
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The CAN Alert and Recovery Example demonstrates the usage of alerts and bus
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recovery in the CAN driver. This example **requires only a single ESP32 module
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to run**.
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The CAN Alert and Recovery Example will do the following...
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1. Initialize and start the CAN driver on the ESP32 module
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2. Repeatedly transmit messages (no acknowledgement required)
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3. Reconfigure alerts to detect bus-off state
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4. Purposely trigger errors on transmissions
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5. Detect Bus Off condition
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6. Initiate bus recovery
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7. Deinitialize CAN driver on ESP32 module
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## External Transceiver and Pin Assignment
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The CAN controller in the ESP32 **does not contain an internal transceiver**.
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Therefore users are responsible for providing an external transceiver compatible
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with the physical layer specifications of their target ISO standard (such as
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SN65HVD23X transceivers for ISO 11898-2 compatibility)
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The CAN controller in the ESP32 represents dominant bits to the transceiver as
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logic low, and recessive bits as logic high. The Alert and Recovery Example
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utilizes the following default pin assignments
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* TX Pin is routed to GPIO21
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* RX Pin is routed to GPIO22
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