jnicolson/twc-controller

TWCController :: Hardware suggestions

M-VdM opened this issue · 8 comments

M-VdM commented

Hi ! Good job ;-)
Have you considered using something like a "ESP32-WROOM-32U" module, so one could connect an external WiFi-antenna ?

jnicolson commented

Hi,
Thanks! I still have lots of things i'd like to add, but it's getting there.

It should definitely be possible to use the 32U module - the board (https://github.com/jnicolson/TWCController) was designed with the PCB antenna module in mind, but the pinout is the same so it should just be a matter of using the 32U module when building it.

The hardware needs a revision as now that i've got it built I've found some things I would change. I'll make a note that either module can be used.

M-VdM commented

I have some more ideas, but I 'll put them in the right thread. Sorry 'bout that.

M-VdM commented

Hi Jarl,

Hmm ... Looks like I can 't post a comment in the hardware thread jnicolson\TWCController ...

To be honest, I have been thinking about developing a similar board (ESP32+MicroPython) ... but you beat me to it ;-)

Have you considered:

  • Sensing J2/J3-pin3 (LED_RED) and pin4 (LED_ORG), so you can "read" the hardware error indicators ?
  • You could even connect to the i2c-bus (jumpered perhaps) on J2/J3-pin5 (SCL) and pin7 (SDA) ...
  • Adding a Temperature+Humidity Sensor ? Always a good idea for such kind of projects.
  • Using an ESP32-WROOM-32U (or another family member) module + a pigtail, so one could connect an external WiFi-antenna ?

Adding that CANbus controller was a smart move. Are we supposed to connect that to CNA5-pin1 (VEH_PILOT) & PE ?

On CNA7/CNB1 (TWC-side), J2/J3 on your board:

  • pin 10 = N/C
  • pin 6=pin 8 = SGND
  • pin 9 = LED_RESET

BTW: are you familiar with this EEVblog entry by CDragon (LINK)? Interesting stuff.

Keep up the good work.
If you need any help in debugging/testing (the hardware) ... it would be my pleasure !

Grtz,
M_VdM.

jnicolson commented

Hi,

Not sure about why you can't comment, but i might actually close out that other one and just combine the hardware into here.

I hadn't considered tapping off any of the signal lines from the LED board, though it wouldn't be hard. Did you have something in mind to do with the data from there? Also is there a description of what LED_RED and LED_ORG do? I couldn't see anything after a quick look (admittedly a very quick look though so i probably missed it).

There is actually a temperature/humidty sensor on there, it's a Sensiron SHTC3 labelled U2 (right middle). On my prototype board I haven't been able to make it work - in hindsight trying to assemble and then toaster oven reflow a part with 0.35mm width pads might have been optimistic. In a rev 1 of the board i might swap it for something easier to use.

The CAN controller was done with the best of intentions but may have been a mistake using a full CAN controller as the charger talks SWCAN instead of normal CAN. I don't know much about CAN but it seems like it may work by tying CAN L to Ground, but it would be better to actually use a SWCAN controller instead. Rev 1 I will swap it for a SWCAN chip but right now i treat it as just not having CAN (i didn't bother to buy or populate the CAN controller on my prototype). Also @craigpeacock has done a lot more work on SWCAN that I have and pointed out that it's a bit more complex due to the fact that the car starts with J1772 signaling and switches resistors in and out, i would need to figure out how to detect when the car switched to CAN mode before phyiscally connecting the transciever.

While it'd be nice to be able to get things like the state of charge, it wouldn't personally benefit me very much as I only have a single tesla and i'm focussed on the green energy aspect and just charging when i have excess solar generation, so state of charge doesn't change my decision making while charging.

The current revision of the hardware is working for the purpose of controlling the TWC (i.e. the ESP32, buck converter and RS485 transciever). I'm a bit limited for free time at the moment so i haven't had a chance to much. I plan to add a few features to the software side and then i'll decide if i want to bother actually getting a Rev 1 of the hardware built (it'd be a decent investment for me unless others were interested in buying them, seeing as my prototype board is working for me!)

Thanks for the kind words!

bgrigoriu commented

Hi ,
Do you still pursue the dev ?
I am very much interessed and would like to contribute albeit I am a newbee.

jnicolson commented

Hi,
I haven't really done much on this - currently i'm pretty sure i'm the only person who's using it to control a Tesla Wall Connector and it's working fine for me. With Tesla not selling the Gen 2 connectors which this works with anywhere (including Australia where I live - they've recently switched to selling the Gen 3 model) I'm not sure how many other people will ever be interested.

Were you interested in using my code to control a wall connector?

bgrigoriu commented
jnicolson commented

Hi,
That description makes sense. The way i wrote this code is a bit different from how TWCManager works - TWC Manager everything is built in, mine is based on listening to messages via MQTT for the charge rate. If you can get the excess generation (in full amps) from Envoy and write that to MQTT then my code should read it and adjust the charge rate.

The only problem is like you said - right now I don't think there's any way to make it work with the Gen 3 chargers (the ones with the glass front). You probably already know this but the way mine and TWCManager works is by using the load sharing protocol which in Gen 2 chargers was via RS485. The Gen 3 chargers are going to do load sharing via WiFi and the internal RS485 port doesn't seem to do very much.

I think it's going to be challening to do much unless someone documents the Gen 3 chargers or you're able to find an older Gen 2 charger from somewhere. I know there are chargers available in Europe which have smart features (like the myenergi zappi, hypervolt and i'm sure others) which have load tracking built in. That probably doesn't help you much if you've already bought a gen 3 though sorry!!

I'm happy to answer any questions i can and if there are specific features which would help i can work on adding them but your biggest issue is going to be interfacing with a Gen 3 TWC unfortunately!