[Ovmsdev] Relay through diag port.

Nikki Gordon-Bloomfield nikki at littlecollie.com
Sun Apr 14 19:01:03 HKT 2013

I've been thinking about this some more, and I think I've come up with a plan. 

If I could pull the IO out there and connect it to a relay driver chip, I think it could be possible to give Twizy owners the same remote on/off charge capabilities as the Tesla. 

My thoughts: 

1) use output one from OVMS to drive a relay which is NO. When the IO output from OVMS goes high, we use that to close the relay, and let power flow, turning on the charger. When it goes low, the relay opens, and the charger turns off. 

2) use a second IO on the OVMS to sense when a switch is pressed on the dash. This allows us to start/stop charging from the vehicle using a simple push-to-make switch. 

3) using a home instance of perl and OVMS client software, write a cron job which turns on the car's charging on/off at a given time every day, or have perl listen for SOC and shut off charging when we reach 80% SOC. 

My goal? To give Twizy owners the ability to use time-of-use metering to get cheaper charging of the Twizy at night-time. And also to allow users to set 80% SOC rather than 100% SOC. It would require folks to run a perl script all the time on their home computers though. 


On 2 Apr 2013, at 14:05, Mark Webb-Johnson <mark at webb-johnson.net> wrote:

> Tricky. It is just a tap into the modem comms.
> But, there is an expansion connector on the board itself.
> The part labelled "HEADER 9X2" is a standard layout for expansion plugs, or holes are there to directly solder to the board. The I/O is 5v digital on those pins, and there are quite a few spare I/O pins that you can use.
> There is also GND, +12V and +5V if you need power.
> If you have a use for this, it would be quite simple to control some of these pins on/off on command (similar to the way home link works).
> Regards, Mark.
> <PastedGraphic-1.pdf>
> <20120814-boarddesign.pdf>
> On 2 Apr, 2013, at 8:56 PM, Nikki Gordon-Bloomfield <nikki at littlecollie.com> wrote:
>> Guys,
>> Is there any scope for enabling IO from the diagnostic port to operate an relay, either directly or through some opto-isolators? 
>> Nikki. 
>> _______________________________________________
>> OvmsDev mailing list
>> OvmsDev at lists.teslaclub.hk
>> http://lists.teslaclub.hk/mailman/listinfo/ovmsdev
> _______________________________________________
> OvmsDev mailing list
> OvmsDev at lists.teslaclub.hk
> http://lists.teslaclub.hk/mailman/listinfo/ovmsdev

More information about the OvmsDev mailing list