Open Vehicle Monitor System (OVMS) - Technical Discussion

[hcsharp]

I'm not a Windows person, so I'll tell you the geek method for finding the assigned IP address which is to open a Command Prompt window and enter the command ipconfig. You are correct that the desktop computer won't show up on your router when it is connected to the OVMS access point.Sorry my use of the term "reset" was unclear. I don't mean a factory reset, just a reset by pushing the reset button (the little S2 pushbutton on the module) or alternatively by removing power by disconnecting the cable that goes to the diagnostic port. When the module restarts after the reset the WiFi will come back up in the configuration that you have set.

Since accessing the S2 pushbutton on the module inside its case is inconvenient, I modified my case by cutting a hole directly above S2 and installing a plastic rod to push on the button. The rod I used was the reset button from a discarded hair dryer GFCI plug which happened to be the right length and shape (after one minor modification) and already had the word RESET embossed on the top. An alternative implementation would be to install a pushbutton switch on the case somewhere and run wires to the board in parallel with S2.

Mark already responded with the commands to reset the WiFi. I use "wifi mode off" and "wifi mode client Revelstoke", where Revelstoke is the SSID for my home network.

OK, that's helpful. But how do I send any commands? I don't have cell access, and I don't have Wifi access. Perhaps I have to hook up the USB cable again.

What is the difference between pressing the reset button and unplugging/ reconnecting the power via the cable?

 

[supersnoop]

What ACC functions do you need? What was your ACC profile in v2?

I could really use the ACC cooldown function. Heck, I’d be happy with just cooldown.

 

[markwj]

I could really use the ACC cooldown function. Heck, I’d be happy with just cooldown.

Cooldown (experimental) was released in 3.1.009. Initiated by 'charge cooldown' command. You can see status with:

OVMS# vehicle status
Vehicle: Tesla Roadster ()

Cooldown is running (with 0 cycle(s) so far)
ESS temperature: 50C/31C Cooldown remaining: 60 minutes

I don't have the car any more, so it is not well tested. But, the status display, and logs shown on the console, and pretty extensive.

2018-08-26 MWJ  3.1.010  OTA release
- TeslaRoadster: Fix for digital speedo bug
- Bluetooth: Improvements towards bluetooth BLE support
- Server v2: Add cabin temperature to "D" message

2018-08-15 MWJ  3.1.009  OTA release
- Tesla Roadster: COOLDOWN command implementation
- Tesla Roadster: Charge Timer support
- Tesla Roadster: Digital Speedo feature implementation
- Tesla Roadster: Refuse to lock a car that is ON
- Server V3: MQTT implementation complete (still experimental beta)
- Mitsubishi iMiev: Basic vehicle support
- CAN: Support LISTEN mode for CAN buses

 

[slcasner]

OK, that's helpful. But how do I send any commands? I don't have cell access, and I don't have Wifi access. Perhaps I have to hook up the USB cable again.

What is the difference between pressing the reset button and unplugging/ reconnecting the power via the cable?

Right, I was meaning that you would issue the commands using the USB cable. Since I've been part of the firmware development team, I have a long USB cable semi-permanently attached to the OVMS in the car and routed around to available storage space on the left side of the driver's footwell so I can easily pull it out to connect to my laptop.

Pressing the reset button or causing a power cycle both have the same effect and are essentially the same. Conceivably there could be a hardware component that is not completely reset by the software that a power cycle would reset, but I'm not aware of such.

 

[Curt]

What ACC functions do you need? What was your ACC profile in v2?

Hi Mark.

My ACC profile in V2 was "ACC PARAMS COOLDOWN CHARGEBY 07:00 MODE STA LIMIT 70"

I'm guessing that the charging mode and Amp limit will just default. Can COOLDOWN on plugin and CHARGEBY be achieved through the current scripting system?

 

[markwj]

Hi Mark.

My ACC profile in V2 was "ACC PARAMS COOLDOWN CHARGEBY 07:00 MODE STA LIMIT 70"

I'm guessing that the charging mode and Amp limit will just default. Can COOLDOWN on plugin and CHARGEBY be achieved through the current scripting system?

The on-plugin cooldown should be scriptable - just a simple script on that event. But, we don't have 'chargeby' support yet.

 

[shrink]

Hi Mark.

My ACC profile in V2 was "ACC PARAMS COOLDOWN CHARGEBY 07:00 MODE STA LIMIT 70"

I'm guessing that the charging mode and Amp limit will just default. Can COOLDOWN on plugin and CHARGEBY be achieved through the current scripting system?

Yes, mine is very similar to @Curt:

During the hot Phoenix summer and when not driving the car that much, I used:

ACC PARAMS COOLDOWN CHARGEAT 01:00 MODE STA STOPSOC 60 LIMIT 13A

I'm traveling off and on the next month and switched to

ACC PARAMS COOLDOWN CHARGEAT 01:00 MODE STO STOPSOC 0 LIMIT 13A

Once the dreadful Phoenix summer passes, I'll switch back to a full standard charge.

As @supersnoop mentioned, I mostly want the COOLDOWN function. Limiting SOC is also key for me during the Phoenix summers. I use low amps because I have 2 Model S's and the Roadster so I try to be gentle to my panel.

 

[Casey_S]

Having an issue using my OVMS v3. Everything's set up properly and when it's on it works, but my diag port doesn't seem to supply a constant 12v. As soon as I turn off the Roadster the module dies and I lose connection. Turning the car back on also doesn't immediately revive the module, I have to unplug it and plug it back in.

Any ideas?

 

[markwj]

Having an issue using my OVMS v3. Everything's set up properly and when it's on it works, but my diag port doesn't seem to supply a constant 12v. As soon as I turn off the Roadster the module dies and I lose connection. Turning the car back on also doesn't immediately revive the module, I have to unplug it and plug it back in.

Any ideas?

Diagnose first. Simplest would be a laptop with USB cable plugged into the module (while module is plugged into the car). The OVMS has an ability to read and display the 12v power supply:

metric list v.b.12v.voltage

With the car on, type that command and see what it shows. Then turn the power off, wait a few seconds, and try again.

That at least will tell you if you have a major issue with the 12v supply. It won't help detect brown-outs.

The module can be powered either by vehicle 12v or USB 5v. If it survived the car on/off cycle with laptop USB connected, but not without, then that would indicate an issue with the 12v power.

 

[Casey_S]

Good to know about that command. I tried manually measuring the voltage while the car was off from the diagnostic port with a multimeter and accidentally bridged 12v to ground for a split second. Got a small spark. Car/VDS/OVMS continued to act as before so it seems I didn't damage anything, but should I be worried? I guess at least I know 12v is still live while the car is off - I just don't know at what voltage. Won't be able to check again until the weekend.

Interestingly, if I plug the OVMS in while the car is off it does briefly create the wifi AP then dies. The OVMS was also failing to provide enough power to keep my Navdy HUD alive today (With the car on), yet it was working last night. My guess is the increased brightness for daytime visibility was drawing too much power. I guess all signs point to an issue with the 12v power? Anything I can do if that's the issue?

 

[markwj]

A trick for measuring 12v is that you can get GND anywhere in the car, so just need to probe with one pin. Trying to probe two pins 'tweezer style' is more risky. You can also probe from the DB9 connector side (pin #9) hole, rather than from the vehicle diagnostic connector (trying to touch a pin just next to GND).

You can also measure 12V from the DA26 expansion connector (while OVMS is plugged in). Pin #18 is switched 12V, and pin #9 is external 12V (unfused on that side, so take care).

Given the symptoms, I think you need to look for voltage drop when things are powered on. If that is happening, then the issue is probably the APS in the battery and that is not good news.

P.S. You have a Navdy HUD connected? Presumably using the OVMS DA26-HUD cable to provide OBDII and the OBD ECU module in OVMS? How is that working out?

 

[ShawnA]

Hi Casey,

It could be your 12 volt aux. battery is on the way out...
You could remove the light in the trunk to measure for a "generic" 12 volts.
If it's bad there you know it's bad for the OVMS.

Shawn

 

[Casey_S]

A trick for measuring 12v is that you can get GND anywhere in the car, so just need to probe with one pin. Trying to probe two pins 'tweezer style' is more risky. You can also probe from the DB9 connector side (pin #9) hole, rather than from the vehicle diagnostic connector (trying to touch a pin just next to GND).

You can also measure 12V from the DA26 expansion connector (while OVMS is plugged in). Pin #18 is switched 12V, and pin #9 is external 12V (unfused on that side, so take care).

Given the symptoms, I think you need to look for voltage drop when things are powered on. If that is happening, then the issue is probably the APS in the battery and that is not good news.

P.S. You have a Navdy HUD connected? Presumably using the OVMS DA26-HUD cable to provide OBDII and the OBD ECU module in OVMS? How is that working out?

Indeed. Measuring it through the DB9 or just attaching leads to the pins donned on me immediately after I tried probing directly but I didn't have much time and was being foolishly impatient. I'll try again this weekend. What're the odds of that quick short damaging something?

Re: Navdy, like I said - worked fine at night, but wasn't staying powered during the day. Tried seeing if I could get the car's information displayed as combustion equivalent analogs but the Navdy would die too quickly for me to see results.

Hi Casey,

It could be your 12 volt aux. battery is on the way out...
You could remove the light in the trunk to measure for a "generic" 12 volts.
If it's bad there you know it's bad for the OVMS.

Shawn

The car spent a while sitting in Japan and I have no idea if the 12v was ever replaced, so probably a good chance it's on the way out. The 12v from the diagnostic port is supplied from the HV battery though, isn't it?

 

[ShawnA]

Hi Casey,

I am not sure... The car does charge the 12 volt from the ESS when it calls for it and when driving.

I checked my car last night and there is a 12 volt outlet (old cigarette lighter) under the console.

Upon further thought it will probably be difficult to measure a good voltage from the outlet because when the car door
is open the systems are powered and this would be indirectly powered by the ESS.

The only mistake proof method of measuring the voltage would be directly at the battery in the right wheel well or
making an extension from the 12 volt outlet out of the car. The measurement at either location would need to be
taken when the car is at rest and silent. Not when the coolant pump is buzzing because of a recently opened door,
recent driving, or current charging of the car. When the coolant pump is running the voltage is indirectly coming from the ESS.

I have found that the 12 volt battery life for me is slightly over 3 years.
Your 12 volt battery life may vary according to your driving and charging habits...

Good luck, Shawn

 

[gregd]

Hi Casey,

I am not sure... The car does charge the 12 volt from the ESS when it calls for it and when driving.

I checked my car last night and there is a 12 volt outlet (old cigarette lighter) under the console.

Upon further thought it will probably be difficult to measure a good voltage from the outlet because when the car door
is open the systems are powered and this would be indirectly powered by the ESS.

The only mistake proof method of measuring the voltage would be directly at the battery in the right wheel well or
making an extension from the 12 volt outlet out of the car. The measurement at either location would need to be
taken when the car is at rest and silent. Not when the coolant pump is buzzing because of a recently opened door,
recent driving, or current charging of the car. When the coolant pump is running the voltage is indirectly coming from the ESS.

I have found that the 12 volt battery life for me is slightly over 3 years.
Your 12 volt battery life may vary according to your driving and charging habits...

Good luck, Shawn

What I have found is that the battery itself is pretty much out of the picture when looking at the 12v system voltages (plural - there are multiple branches). When I had my 12v battery replaced a few years ago I had the tech wire in a connector up under the hood (so I could "jump" the car if needed). To my surprise, that connector shows 13.77 volts pretty much no matter what the car is or has been doing. On, off, charging, sleeping, whatever; it doesn't move more than 0.01v or so. Note that a 12v lead-acid chemistry battery has a resting voltage of about 12.6 volts, well under the 13.77 that I measured. Based on that, I have to believe the 12v system is primarily fed from a DC-DC converter in the ESS somewhere, and the actual 12v battery is just there as a backup.

To the OVMS voltage, on mine I find that when the car is awake, the voltage is about 12.95 volts, and when asleep it drops to about 11.32. This is as measured by the OVMS, which I have not calibrated. From the web browser's Shell tab or the USB console, you can view these with the command 'metrics list v.b.12v.voltage'.

I've run the module's OBDII port to a no-name HUD ("Made in China" prominently displayed on the box), and it claims the 12v is at about 12.9v by its internal meter, and 12.5v if I map the v.b.12v.voltage metric to the display's PID 0x10 (fuel flow), both while the car is on.

So bottom line, one can never be truly sure what the "12v" system is actually supplying, other than it should be enough to run the module and OBDII display. Most of the HUDs have a way to monitor the 12v system. What does yours say?

Pretending to be a hardware engineer, I can imagine that the 12v going to the diagnostic connector (the one that drives the OVMS module) is fed from more than one path inside the APS, and that your momentary short might have damaged one of them. Running OVMS from both the diag connector and a USB port should keep it alive to display the voltages, as markwj suggests, while the car is awake and asleep, so you can see what's happening in a relative sense. You might check the fuses (passenger-side dash behind the cover) to see if one has popped.

 

[Casey_S]

Sitting in the Roadster now, trying to read the diag voltage with the OVMS. I'm getting 12.93v with the car on, 13.12v with the key at accessory power, then it cuts once the key is removed from the ignition. I've got it plugged into my laptop but as long as it's plugged into the diag and the car is off, the OVMS refuses to turn on.

Edit: looks like something was wrong with the module. Tried using the Navdy with the car on, and I noticed the Navdy started to flicker again. Measured OVMS voltage and got 7.97v, then it died. When it came back its configuration was reset to factory and I was measuring 13.12v with the car off. Going through initial configuration again now with the OVMS plugged in to the car while off.

 

[gregd]

Odd. The Accessory outlet in my car drops 12v several minutes after the key is removed, not immediately. It's synchronous with the battery circulation pump, i.e. when the car is "awake".

The diag port (and hence the OVMS) should be on continuously. Power to the OBDII port on the back of the OVMS is controlled by "ext12v", so commands 'power ext12v on' and 'power ext12v off'. It can be turned on at module boot by the auto start configuration, but default is off.

 

[Casey_S]

Was indeed an OVMS issue. I think there was something wrong with the firmware. Going through the config failed a few times with the car off - I'd name the wifi AP yet "OVMS" would persist as a separate AP, and my named AP would die and fail to return after skipping the firmware update steps and setting the car config to Roadster. I pulled into the garage where I'd get WiFi access, went through the process again with the car on and installed the firmware again, and now it seems to be working as intended with the car off. Just measured 13.08v with the pump cycling and car off, 11.55v sitting silently and off.

Edit: still having issues. I set the autostart options to accommodate the Navdy and restarted, and my configuration was lost and the "OVMS" AP was back. Looks like my configuration doesn't persist on power loss. I went through the process again, and turned on OBDII power with power ext12v on. While messing with the Navdy it started flickering again, I measured the OVMS voltage at about 7.5v again, and it died. Stock settings were restored. While the Navdy was working, I also tried running the commands to sync the external 12v state to the car's on/off, but the shell was giving me an error; "Could not create VFS directory." Looks like I don't have write permissions, so to speak.

 

[ShawnA]

Hi Casey,

It does not seem like your device ever successfully saved your configuration changes.

Or imagine that it has saved the changes and passes through the 7.5 volts to the Navdy.
It still sounds to me like the 12 volt battery is on the way out.

My experience differs slightly from Greg_D with the 12 volt battery.
I took the Roadster to lunch and it locked OK with the key fob. (Because the pump was still under ESS control.)
When I returned the car would not respond to the key fob (dead 12 volt battery).
Preparing to lie on the ground to manually unlock the car with the key
I must have pressed the door handle which activated/awakened the 12 volt from the ESS.
Hearing coolant pump running was my clue and it did unlock with the key fob.
I had the 12 volt battery replaced and it was good until the next 12 volt battery failure.
I have had the Roadster 9 years now and I am on my third 12 volt battery...

It sounds to me like you are on the same path...

Can you augment your 12 volt battery?
Maybe a 12 volt charger or "booster pack" that works through the cigarette lighter.
It would be nice it you could get through one cycle of programming, saving changes, and observing Navdy
with a good 12 volt source....

You would have a better indication of the failure point...

Shawn

 

[markwj]

Trying to read through this and understand exactly what is happening, but unclear...

There are three 'states' to the car power:

1. Ignition on
2. Ignition off, but car awake
3. Ignition off, and car asleep

You can hear the difference between #2 and #3 by whether the little cooling pump is working (at the back right corner of the car, beside the pem). Typically, that will run for 5 minutes after the car ignition is turned off. That awake/asleep also controls 12v accessory power. Opening a door, or charging, will bring the car back to #2.

My question is: Do you get 12v on the diagnostic connector in all 3 cases?

Regarding the inability to save configuration settings, this could be caused by a problem in the configuration store. Simplest is to type the command "module factory reset" (followed by 'y' for yes) and the system will reformat everything and return to factory defaults (although firmware will be left running OTA firmware, or whatever firmware was previously loaded).