Newb Asks: Does the Lexus GS450h VCU have any Serial Pins for Communication?

[Gregski]

so after the drivers are installed you can physically connect the four Dupont like wires to the CP2102 adapter, it's pretty straight forward, just remember that the Tx goes to the Rx and the Rx goes to the Tx, that little red thingie is labeled as is the Nextion side

Red - you can use either the 3.3v or the 5v (I put mine on the 5v, more is better, lol)
Black - ground
Yellow - Tx (comes from Rx on the Nextion)
Blue - Rx (comes from Tx on the Nextion)

[Gregski]

OK, now that we are tethered to the PC instead of clicking on File \ TFT File output, we will click on the Upload button on the menu, leave everything as is aka Com Port: Auto Search, cross our fingers and simply click Go... and watch the magic happen, and that's it that's the other way of saving that TFT file to the Nextion display, so you do you

found this video on YouTube for you

[Gregski]

space reserved for other stuff that we want to say/add about prepping the Nextion display prior to moving on to coding on the VCU (aka Arduino)

[Gregski]

All the above would either need modifiying the SAM3X code to get the correct format on serialdebug to drive the Nextion display or an external processor to covert from async serial to Nextion/I2C. I think the suggestion from a few days ago of using CAN bus and arduino would be best. This would also allow driving both displays together if needed.
I found a simple example on github of CAN to Nextion display. https://github.com/DefinitiveDiagnosis- ... xtion-Dash

I don't think Nextion displays use I2C bus aka serial clock (SCL) and serial data (SDA) lines I think they just use UART Rx Tx (or at least my model NX3224T024 does) which is the same "protocol" the ol' red ESP8266 WiFi card speaks

I do see that the 1602 or the 2004 LCDs use SCL/SDA pins on the Arduino boards aka the I2C bus so not sure we can spit that out via the VCU

[Gregski]

please keep this in mind as as you sharpen your coding pencils

The Nextion has a built-in ARM microcontroller that controls the display, it communicates with any microcontroller using serial communication at a 9600 baud rate, so it works with any board that has serial capabilities like our beloved VCU.

this means the first thing we need to do is search for a line of code that has this string in it: "Serial2.begin" and change the baud rate in it to 9600, it may look something like this:

Serial2.begin(19200); //setup serial 2 for wifi access

I like to just remark the original line of code by putting two whack whacks in front of it then copying that line directly below it and making my changes in the copy, and since everyone is watching add some internal documentation inline

// Serial2.begin(19200); //setup serial 2 for wifi access
Serial2.begin(9600); //setup serial 2 for Nextion display

[andybpowell]

I like the way this went from a question to a tutorial I have to say once you get used to the nextion editor and get the hang of how you send data to and from the device they're really flexible and simple I started using them about 4 years ago when I used one in my airide setup and haven't looked back I currently use one in my Z3 to monitor bms, charging and even interface with my VCU to give an eco/sport function

the only issue with them is that they can be pricey

[Gregski]

I like the way this went from a question to a tutorial

Dunning–Kruger in full effect

I have to say once you get used to the nextion editor and get the hang of how you send data to and from the device they're really flexible and simple I started using them about 4 years ago when I used one in my airide setup and haven't looked back I currently use one in my Z3 to monitor bms, charging and even interface with my VCU to give an eco/sport function

image.png

the only issue with them is that they can be pricey

very nice, I see that Nextion makes four lines of displays, so which one did you go with, I ask because my Basic Series struggles with displaying all the data I am trying to send to it at 9600 baud rate and I am not sure if we can increase it on those models, I think maybe one can on their Enhanced series

[andybpowell]

I have the same issues I send my data in blocks so refresh rate is not ideal I've also considered going to the discovery or enhanced
if you're referring to the baud rate you can alter it on all models mine is at 115200 but doesn't seem to help

[Gregski]

a little VCU VooDoo to make the UEXT connector spew out data via one of the regular 20 pin connectors so that we can put the case back on the PCB

the red thing is the older design WiFi card, it's pretty bad @ss for that little thing, it is literally a WebServer/DHCP server, yes that little guy

please don't mind the black wire, it's from a prior voltage regulator repair (the ground in middle earth of the PCB got destroyed)

the best part about this crazy solution is that you can still plug in the WiFi card back in, so I hope to use it to display digital gauges on my Android tablet, and charging status on the Nextion when I am in Charge Mode

[Gregski]

Another Enuff About You and More About Me Update: AEAYaMAMU

so just made some more better screens on the Nextion to show my super very simple charging cycle (there is an explanation for some of the text not being centered on the scree, I am simply sharing / reusing the already defined text boxes)

1. The Nextion display is simply powered on and waiting to see which way I turn the key in the ignition switch (Left = Charge and Right = Not Charge, lol aka Drive)

2. Here we are charging showing AC electricity going in (what I call "pulling") into the Chevy Volt charger and DC electricity going out (what I call "pushing") electricity out of the charger and into the BMW PHEV battery pack

3. and this is a simple message that tells me the charging is done

so I just used the same 8 boxes/fields to display all this, essentially 4 on the left for labels and 4 on the right for values, but at this time still all four created just as text boxes, still learning and trying to figure out this Nextion VooDoo

[Gregski]

hey! these guys stole my idea, but they did it a few years sooner


VERO ELECTRIC 2.4″ BASIC BMS DISPLAY

[Alibro]

Hi Greg
I was looking for details on the Olimex WiFi module and came across this thread.
Thanks for doing such a great job of explaining to the grey cell challenged among us. I still haven't cracked the Olimex yet as that is a work in progress but you mentioned putting the display up on an Android unit and that is something I have cracked.

As you can see I even managed to get pack voltage up on the display from the (in my case) Nissan Leaf Inverter rather than a shunt, but I want to make changes to the WiFi Display so that's why I'm working on the Olimex.

BTW I bought 12 of them so I would have spares and wouldn't need to destroy the one Damien supplied so I will be selling some later if anyone in the UK is interested. They are dirt cheap until you see the shipping cost to the UK.

[Alibro]

You clever guys may already know this but Ver B of the Olimex doesn't require soldering to configure.
After spending several hours struggling soldering, desoldering and resoldering GPI0 I discovered Ver B of these boards have a button you can hold in while powering on to put it into UART mode.