no CAN frames from 2016 Nissan Leaf

[EccentricDyslexic]

Hi all,

I’m building a DIY OVMS v3 setup to monitor and eventually control charging on a 2016 Nissan Leaf (goal is to stop charging around ~70%). The OVMS firmware appears to be running correctly and I can access the web interface and shell over Wi-Fi, but I’m not receiving any CAN traffic at all.

Hardware setup

• ESP32 TTGO WROVER
• SN65HVD230 CAN transceiver (Waveshare module)
• Powered from 3.3 V
• OVMS firmware build: idf v3.3.4

ESP32 ↔ CAN transceiver wiring

• GPIO4 → CAN_RX
• GPIO5 → CAN_TX
• 3V3 → 3.3 V
• GND → GND

CAN transceiver ↔ OBD wiring tested

I have tried both possible Leaf buses:

EV-CAN:

• OBD pin 13 → CANH
• OBD pin 12 → CANL

CAR-CAN:

• OBD pin 6 → CANH
• OBD pin 14 → CANL

Ground from OBD pin 4/5 is connected.

I also swapped CANH/CANL once to rule out reversed wiring.

OVMS commands used

can can1 start active 500000
can can1 rx standard 0

and

can can1 rx extended 0

Result: no frames appear at all.

The CAN controller starts successfully:

Can bus can1 started in mode active at speed 500000bps

but the RX monitor shows nothing, even with the car in ACC and READY.

Things already checked

• ESP32 pins verified (GPIO4 and GPIO5)
• SN65HVD230 powered from 3.3 V
• CAN bus started at 500 kbps
• Tested both EV-CAN (12/13) and CAR-CAN (6/14)
• Tried swapping CANH and CANL
• Car awake (ACC and READY modes)

Questions

1. Should the 2016 Leaf definitely show traffic on the OBD connector, or is the EV-CAN bus behind a gateway that requires tapping elsewhere?
2. Is the SN65HVD230 module compatible with OVMS CAN1 on ESP32, or do I need MCP2515 / different hardware?
3. Are GPIO4/GPIO5 the correct pins for OVMS CAN on ESP32 builds?
4. Is there any OVMS configuration step I might be missing before CAN frames appear?

Any guidance would be greatly appreciated. I feel like I’m missing something basic but I’m not sure where the problem is.

Thanks!

[dexterbg]

can … rx simulates receiving frames by injecting them into the CAN framework, can … start is all you need.

GPIO4/5 is wrong and matches neither the OVMS defaults nor the LilyGo T-Call pins. See pin definitions ESP32CAN_PIN_TX & ESP32CAN_PIN_RX, change them as needed:
https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/blob/master/vehicle/OVMS.V3/main/ovms_peripherals.h#L103

In case you want to define a full hardware model for the TTGO WROVER, have a look at the GPIO maps:
https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/tree/master/vehicle/OVMS.V3/components/gpio_maps

Regards,
Michael