Twizy-Cfg SEVCON configuration shell

This is a minimalistic SEVCON Gen4 configuration shell for Arduino.

It's a port of my SEVCON core functionality from the OVMS project, with a simple command interface on the Arduino serial port.

It currently only supports reading & writing SDO registers and entering/leaving pre-operational mode. Support for the OVMS/Twizy tuning macro commands (i.e. power, speed, recup etc.) has not yet been ported.

So currently you need to know the registers and value scalings for your tuning needs. Read the SEVCON Gen4 manual for some basic description of registers. The full register set is documented in the SEVCON master dictionary, which is ©SEVCON. It's contained in the SEVCON DVT package.

Most registers of interest for normal tuning can be found in the Twizy SDO list.

Note: SEVCON write access has been limited by Renault on Twizys (SEVCONs) delivered after June 2016. The write protection applies to all power and driving profile tuning registers, and also to the battery limits. A locked SEVCON will respond to register writes with an error. You can also check the software version (rs 100a 00): if it's 0712.0003 or higher, the Twizy is locked.

Hardware requirements

1. An Arduino (a Nano will do)
2. An MCP 2515 SPI CAN module, i.e. a "CAN-BUS Shield"
3. An OBD2 plug/cable for the MCP module

Installation

To download, click the DOWNLOADS button in the top right corner, download the ZIP file. Extract the ZIP, open TwizyCfg/TwizyCfg.ino from Arduino IDE.

You will also need this library:

• MCP_CAN_lib by Cory Fowler

Enter your CAN module configuration in the TwizyCfg_config.h tab.

Usage

Connect to the OBD2 port, switch on the Twizy, start the sketch & open the serial monitor. Set the serial monitor line mode to "new line".

The Arduino will display a help screen, then wait for your commands:

Function	Command
Show help	? / help
Enter pre-op mode	p
Enter op mode	o
Read numerical register	r <id> <sub>
Read string register	rs <id> <sub>
Write register	w <id> <sub> <val>
Write-only register	wo <id> <sub> <val>

• <id> & <sub> define the SDO register to access, need to be given as hexadecimal numbers
• <val> is the value to write, needs to be given as an unsigned decimal number (negative = two's complement, see below)

Examples:

• Get firmware version: rs 100a 00 (if it's 0712.0003 or higher, the Twizy is locked)
• Set brake recuperation to 30%: w 2920 04 300

The shell automatically logs into the SEVCON with access level 4 (highest user level, 5 is reserved for SEVCON engineering), so all user SDOs can be written to. See SEVCON master dictionary for access levels. Note: all logins are logged in the SEVCON event logs. See SEVCON manual on how to access the logs.

When writing to a register using w, for convenience the old value will be read and shown. For write-only registers use wo to skip the read operation.

The shell does not know about the data type of the SDO accessed (that's why you need to use rs for string SDOs). It handles all numerical registers as being unsigned long. To convert to/from negative values, build the two's complement value by adding the offset:

Type	Negative offset	-1 = …
Integer8	256	255
Integer16	65536	65535
Integer32	4294967296	4294967295

Most signed tuning registers are of type Integer16. See Twizy DCF for register data and access types and default values.

Error messages are mostly self-explanatory, i.e. "SEVCON OFFLINE" means you haven't switched on the Twizy.

Author

Twizy-Cfg and the OVMS Twizy adaption has been created and is maintained by Michael Balzer (dexter@dexters-web.de / https://dexters-web.de/).

Some of the functions contained in the "utils" module have been written by other OVMS contributors.

Donations

Donations to support my efforts and further development are very welcome.
Please send donations via Paypal to: dexter@dexters-web.de
Thanks! :-)

License

This is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this software; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110- 1301 USA

Have fun!