CAN Simulation: RCD 320 with AVR & MCP2515

Hello everyone,
I'm using a RCD320 head unit on my bicycle with a trailer, and I want to try experimenting with a CAN bus simulator.
The idea is to connect the ACC (adaptive cruise control) to the CAN bus so that the radio doesn't turn off after an hour.
'Also, I'm also planning to add lighting and recreate a steering wheel remote control that will be mounted on the bicycle handlebars.'
I've now acquired an AVR microcontroller and an external board with an MCP2515, which I intend to control via SPI.
Okay, I'm still missing a few minor details. Once I have the ID for the ACC (Adaptive Cruise Control), do I need to send a Telegram message permanently, or just once, or at specific intervals? The same applies to the lighting. Or is it sufficient to send one Telegram message with the information 'ON' or one with 'OFF'?

Best regards.

DIY enthusiast.

Hallo,

das Telegramm muss permanent in einem bestimmten Intervall gesendet werden.

Viele Grüsse, Rainer

Thanks, Rainer, for the information. Do you have any more details about that? Specifically, what's the interval? I'm also looking for information on the IDs and what other functions can be accessed through the radio.

DIY enthusiast.

Hallo,

bei den Intervallen kannst du Dich an Traces aus dem jeweiligen Fahrzeug orientieren, diese sind je nach ID und Bus (Antrieb, Komfort etc.) unterschiedlich.
Am besten schauen wie es in einem Fahrzeug gelöst ist und dann die entsprechenden Nachrichten "nachbauen".
Einige CAN-Traces findest du auch hier im Forum verstreut.

Viele Grüsse, Rainer

Okay, then I'll look for someone who can provide me with a trace report from their Volkswagen. I've already found the IDs that I need.

I have one more question about the MCP2515: I have CAN H and CAN L on the module, and the radio has CAN+ and CAN GND. Are these two different things, or should I connect CAN H to CAN+ from the radio and GND to GND?

You'll need to connect both the CAN High and CAN Low lines. While CAN is technically a two-wire bus, there's also a CAN ground (GND). However, you usually don't actually need the GND in a vehicle because there's typically already a potential difference (ground offset) present.