smallCANboard also known as Small CAN Board

[AndreyB]

Not sure what this is but it seems to consume under 0.003A while waiting for (any) CAN bus activity to wake it up. First usage of new https://github.com/andreika-git/hellen-one/tree/master/modules/mega-mcu64/ module - that's the smallest package for stm32f40x

More details see https://rusefi.com/s/scan

[mtmotorsport]

How much lua program space?

[AndreyB]

How much lua program space?

How much do you need? At the moment it's 50K

How would you use it?

If I have orders I can try using STM32F413 or STM32L496RG. STM32F413 actually has third CAN bus if anyone has a use-case for third CAN bus.

[mtmotorsport]

I was thinking along two lines.

One is a CAN gateway. Something to communicate with different buses (at different speeds). For things like OEM chassis integration, or passing info from one bus to another. Having the ECU broadcast at 500k, and then this device can pass some messages to a 250k bus, or a 1M bus. Most race car data aquisition systems are 1M can bus, but if you are trying to integrate some 250k bus data and some 500k bus data it could be useful to have 3 can bus lines.

Second is a generic I/O extender. Like this has 4 low side outputs that can be used to control non time critical devices (warning lights, rad fans, etc) so an ECU that is either limited by I/O like a MRE, or by connection to an OEM wiring harness such as the Hellen based direct plugin ECUs. Add this small can board to get IO that you either don't have physical pins for, or don't have wiring in the stock harness for.

[mtmotorsport]

How much do you need? At the moment it's 50K

Lua memory heap usage: 29830 / 60000 bytes = 49.7%

[mck1117]

do these exist? possible to buy one somewhere?

[AndreyB]

do these exist? possible to buy one somewhere?

will ship you one tomorrow

[mck1117]

is the schematic shared somewhere? looks like the links on the wiki are broken.

[AndreyB]

is the schematic shared somewhere? looks like the links on the wiki are broken.

yes, just fixed https://github.com/rusefi/rusefi/wiki/Small-CAN-Board

[AndreyB]

[mtmotorsport]

Just got mine, plan to play around with it soon

[zed65]

Is there a standard in CAN communication between ECU's?
Can you use this board on a different ECU or can RusEfi communicate with a box from say MaxxEcu or Haltech?

[AndreyB]

Can you use this board on a different ECU or can RusEfi communicate with a box from say MaxxEcu or Haltech?

There is no standard unfortunately.
This box is a very flexible but pretty advanced tool - it allows a high degree of customization using Lua scripting language. For instance https://github.com/rusefi/rusefi/blob/master/firmware/controllers/lua/examples/ms29bit.txt is an integration between rusEFI and a 3rd party control unit - someone had to develop that script for that specific application.

[mtmotorsport]

How much lua program space?

How much do you need? At the moment it's 50K

How would you use it?

If I have orders I can try using STM32F413 or STM32L496RG. STM32F413 actually has third CAN bus if anyone has a use-case for third CAN bus.

Looks like 25K?

Code: Select all

2023-11-02_11_27_21_789: EngineState: Lua memory heap usage: 14163 / 25000 bytes = 56.6%
2023-11-02_11_27_21_790: EngineState: confirmation_luamemory:9

[AndreyB]

Looks like 25K?

Let's see if https://github.com/rusefi/rusefi/commit/dac73c6b8a446c39bb966fdf99bbc6ba4e22a0ed fixes it, please update to latest snapshot in a couple of hours. I do see 50K working locally

Code: Select all

2023-11-02_11_53_00_833: EngineState: Lua memory heap usage: 14163 / 50000 bytes = 28.3%

[mtmotorsport]

Code: Select all

2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x18EFFF21 mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x18EFFF18 mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x14EF111E mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x14EF1121 mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x18EF2100 mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_284: EngineState: Added Lua CAN RX filter id 0x11223344 mask 0x1FFFFFFF without custom function
2023-11-02_14_36_35_285: EngineState: LUA script loaded successfully!
2023-11-02_14_36_35_285: EngineState: Lua memory heap usage: 29822 / 50000 bytes = 59.6%

great succes.