DIWHFOC… Or… Welcome our Roadster to Telematics enabled EV driving.

So, DIWHFOC… (or Do It with help from online community) project for the Tesla Roadster is the implementation of the OVMS (Open Vehicle Monitoring System).

Had some challenges with the initial install, specifically in getting the SIM card to run on GPRS. Thanks to the folks that have created OVMS it was really quite straightforward.

So, what were my challenges.

First, I picked up a SIM card from AT&T and activated it on the Pay as You Go 10cent per minute plan. I tested on an original iPhone, which was a mistake because it defaults to try to connect as a smartphone, so that doesn’t work.

Second, I forgot to activate the 200 message plan (for configuration). Each command uses TWO text messages as you send a command and the box replies (using two messages), if you forget to buy the $4.99 200 message plan, you end up using $0.40 per command.

Third, the GPRS stops allowing access to the commands when you reach $5 or less. So, the combination of forgetting to activate the 200 text message plan AND finally trying GPRS after the balance fell below $5.00 meant I was stuck sending commands, but NOT being able to use GPRS.

After I recharged again (to go above $5.00), then it started to work.

Any useful hints… Instead of using a cell phone to text commands to the OVMS Module at setup, you might want to consider using Google Voice or some web based SMS program. The reason for this is this will allow you control of the module from your registered number via various devices easily rather than passing along the syntax of COMMAND PW in a text message. There are arguments both ways about whether this is secure or not, the most secure thing would be to unplug OVMS when you don’t want to use it. Then again anyone can text command your Roadster if they know your number and password.

So, a picture IS worth a thousand words.

Here is what it looks like before AND after the install (on the passenger side)


Here is a picture of the box installed at the footwell of the Roadster.

Here is the link to the full set.

I opted to follow the instructions to install the antenna behind the passenger seat. So, I did tuck the antenna wire around the door and up to behind the seat.

Here is where I plug in the DIAG port to the OVMS box.


Tucking in the DIAG port and OVMS cable back in the trough between the driver and passenger.


Ran the antenna cable as decribed in the guide. I installed the antenna behind the seat and ran the cable back to the box through the gasket and door panel. It is a little tough to pull the panels, but it does give way and come back.



Tuck the slack around the space before you plug the antenna into the OVMS bug.


Then tuck it all into place.

Test on the app, and it should all work.

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