[Twiz O'Meter] Expansion port: technical information.

If you would like to customize your ToM more you can easily do this using the expansion port, which is the middle cable coming from the Blackbox.
For other info about this port you can refer to the ToM user manual.


Here I'd like to add other technical information.

The VCC wire provides 5V DC, with max 250/300 mAh. If you exceed this current the fuse inside the OBD connector will burn.
Pin 1 & 2 can be used, indipendently, as input or output, active low or active high, according to the settings of the web server "Expansion board" page.

Pin 1 & 2 are connected directly to the ESP32.
For this reason the voltage in these pins is limited to 3.3v.
So, if you want to use them as input, you have to use a resistor divider.
In the picture below you see the resitors values you can use according to the input voltage.
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When you use Pin 1 or 2 as output, to control for example a relais, it's preferable to set them as active high.
In the picture below you see how you can connect a relais, throght a transitor, on these pin.
.

Moin Zusammen,

kann mir jemand die Bezeichnung von dem Connector nennen ? Hab schon gesucht, aber irgendwie nicht gefunden.

Danke vorab.




LG Tom

Look here.
Do you need the male connector?
I can send some pieces to you, I have many here...

Delvecchio schrieb: Look here.
Do you need the male connector?
I can send dome pieces to you, I have many here...

Hi Fabio,

Thank you, that helps me.
I order them myself because the postage would be more expensive...

LG Tom

Hi @Delvaecchio: what is the plug at the end of the extension connector called? I need to order a connector somewhere to connect my relay board.

I also need to to look at a way to get a permanent 12V somewhere, but the weather has been horrible the last weeks. Is there is permanent 12V in the OBD2 plug? Or would it be better to get a permanent 12V somewhere else?

PriusTwizy schrieb: what is the plug at the end of the extension connector called?

XH2.54

PriusTwizy schrieb: Is there is permanent 12V in the OBD2 plug?

Yes, on pin 16.

PriusTwizy schrieb: Or would it be better to get a permanent 12V somewhere else?

Did you tried with if th power of the cigarette lighter is permanent?

Delvecchio schrieb: Did you tried with if the power of the cigarette lighter is permanent?

That is not permanent. I know this because I charge my phone from it, and the power disappears when I switch off the Twizy.

Radio connector?

Delvecchio schrieb: Radio connector?

I don't quite know what that is (in a Twizy). It doesn't have a radio?

Look at this link.

The weather is still cold and miserable on most days, so I haven't taken the time to install a 4G modem in my Twizy. However, I do have all the parts, and I think I built up the system:



The USB power meter is only there for testing purposes etc, that will not be installed in the Twizy. The black object in the red positive line is a fuse holder with a 2A fuse.

The relay (bottom left) must be operated by the ToM. I don't use my ToM button, so I was wondering if I could use the button's plug to connect the relay to the ToM?



I could peel the grey stuff away, and then connect the relay to the ToM's GND and 5V lines, am I correct?

-edit-

While I was typing this, an idea popped into my head. How much current can the ToM expansion port's 5V line deliver? Is it thinkable that I power the 4G modem directly from the 5V line?

The following notes are only suitable for the owners of the old black-box format, who upgraded to ToM+.
Old black-box is protected with oneshot 500mAh rapid fuse.
ESP32 with the display, when switched on, drains around (to stay on the safe side) 200mAh.
So you have 300mAh free before the fuse burns.
If the max consumption of your 4G modem is less, than you can power it directly with ToM.
However, since the internal voltage regulator is rated for more than 2A, in case the total consumption (ESP32 + 4G modem) is more than 500mAh, you can change the fuse inside the ToM OBD connector with a bigger one (you'll need a soldering iron for this task).

About the connections:
- if you use your DC/DC converter also to power the relay pcb, you can cut the button and use the wires for GND and S (signal input) of your relay. 5V DC will be taken from your DC/DC converter.
Looking at our photo of the button connector, the right wire is GND and the left wire is PIN1. But it's better you check with a multimeter.
- if you won't use your DC/DC converter to power the relay pcb, peel the gray zone (it's hot glue... nothing special) untill you reach the pins. The pin wich goes to red wire is 5V DC (the precise voltage will be around 5,6V), the one which goes to black wire is GND, the other two pins are Pin1 (usually yellow) and Pin2 (usually blue).

All right, thanks a bunch!

I'll think about it for a bit, but I'll think I'll go for the relay + 12V-converter setup, like in my photo. I think there's a good chance the 4G modem could consume peaks of more than 300mA when 4G and wifi are active, and I don't want to blow a fuse in my ToM.

Now I hope for better weather - especially warmer weather - so that I can go hunting for a permanent 12V point in my Twizy. I'll certainly post it here when I've made progress.

You can find a permanent 12V from Battery on the radio iso plug, located beloe the left conpartment where the OBD2 plug sits

OK finally we had some good weather AND I had some time (rare combination).

The permanent 12V was easy, I just took that off the GND / battery pins in the OBD2 plug.



I measured it, and my little setup is now connected directly to the 12V of the aux battery. Perfect.

But now I'm running into something weird. When the Twizy is off (ignition key not inserted), and the ToM plugged in as normal, I measure 5V on the red and black wires of the expansion port. This seems to be permanent? On the yellow I blue wires, I measure a little over 3V. Starting the Twizy does not change this situation; 5V on the red wire, 3+V on the expansion pins.

After this discovery, I did not connect the relay to the GND/5V lines of the expansion port, because this would keep it energised the entire time, connecting the 12V/5V converter to 12V the entire time, thus keeping the 4G modem on all the time. This would drain the 12V aux battery, which is exactly what I want to prevent.

So, do I misunderstand something? I thought the 5V on the expansion port would switch on and off with the ToM. Or have I missed a setting?