May 2018 - OvmsDev - Open Vehicles

MS_V_BAT_SOH
by Mark Webb-Johnson 04 Jun '18

04 Jun '18

What is MS_V_BAT_SOH used for? For Tesla Roadster, as well as SOC, we have SOC LIM MIN and SOC LIM MAX. I want to make those available. Kia Soul seems to use: StdMetrics.ms_v_bat_soh->SetValue( 110 - ( m_b_cell_det_max->AsFloat(0) + m_b_cell_det_min->AsFloat(0)) / 2 ); Nissan Leaf uses: StandardMetrics.ms_v_bat_soh->SetValue(ah / newCarAh * 100); Twizy uses: CAN_BYTE(5) on ID 0x424 Which is it? An overall indication of battery health? 100% being perfect, and 0% a brick? Or battery capacity (100% being a new car, and 50% being one who’s range is only half that of a new car)? The definition here seems to lean towards #2 (capacity related), but seems arguable: https://en.wikipedia.org/wiki/State_of_health State of health (SoH) is a figure of merit of the condition of a battery (or a cell, or a battery pack), compared to its ideal conditions. The units of SoH are percent points (100% = the battery's conditions match the battery's specifications). Typically, a battery's SoH will be 100% at the time of manufacture and will decrease over time and use. However, a battery's performance at the time of manufacture may not meet its specifications, in which case its initial SoH will be less than 100%. As SoH does not correspond to a particular physical quality, there is no consensus in the industry on how SoH should be determined. The designer of a battery management system may use any of the following parameters (singly or in combination) to derive an arbitrary value for the SoH. Internal resistance / impedance / conductance Capacity Voltage[2] Self-discharge Ability to accept a charge Number of charge–discharge cycles In addition, the designer of the battery management system defines an arbitrary weight for each of the parameter's contribution to the SoH value. The definition of how SoH is evaluated can be a trade secret. Kia Soul seems to be closest to the implementation I was thinking of. Find out the difference between SOC LIM MIN and LIM MAX, and use that as an indication of imbalance in the pack. But Nissan Leaf seems to be more like (CAC/160)*100 (where 160 is the CAC for a brand new vehicle). Or should we just add SOC_MIN and SOC_MAX if these are used in many cars? Or an imbalance percentage? Or should we combine the both (so CAC/160*100 gives us percentage capacity loss, and SOCMAX-SOCMIN/SOCMAX*100 gives us imbalance of the pack, then we perhaps multiply the two together to give an overall indication of health)? Thoughts? Regards, Mark

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HUD cable is up on FastTech
by Greg D. 30 May '18

30 May '18

Looks like the OVMS to OBDII-F cable is stocked! https://www.fasttech.com/products/0/10000001/9652027-ovms-v3-hud-obd-ii-f-c… Greg

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Mongoose update (git submodule update)
by Michael Balzer 30 May '18

30 May '18

Re: https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/issues/120 I've pushed an update to our mongoose clone that should solve the spurious crashes in mbuf_insert(). After the next git pull, you will also need to do a git submodule update. Please test for your setups and report if the crash still occurs or any new issues come up. Regards, Michael -- Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal Fon 02333 / 833 5735 * Handy 0176 / 206 989 26

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3.1.006
by Mark Webb-Johnson 28 May '18

28 May '18

Deadline for the factory firmware is this weekend. The modules have all been built and are waiting sim cards, firmware flash, then final QC. So, I suggest we freeze things as they are. I will double-check the wifi setup tonight (it seemed ok last time I checked, so hopefully good now). Build will not include the bluetooth code I am working on (that is disabled in our default sdkconfig anyway). Is there anything else holding this up? Or anything anybody wants to rush in? Regards, Mark.

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Automatic vehicle notifications
by Mark Webb-Johnson 25 May '18

25 May '18

It is time to implement vehicle notifications (charge started, charge completed, charge interrupted, etc) in the vehicle modules I am supporting. It seems that this can be done in the vehicle.{h,cpp} framework in a standard manner, and work across all vehicle types. However, I guess that will break any notifications already being produced by other vehicle types. My suggestion is: A config parameter ‘notifications’, with individual instances to turn on/off the notifications. Default is all enabled. OvmsVehicle::MetricModified picks up metric changes and issues the standard notifications (checking ‘notifications’ parameter appropriately). charge_mode=>charging: Notify charge started charge_mode=>topoff: Notify charge started charge_mode=>heating: Notify battery heating started charge_mode=>done: Notify charge completed charge_mode=>stopped: Notify charge interrupted valet_mode=>on: Notify valet mode enabled valet_mode=>off: Notify valet mode disabled alarm=>on: Notify alarm is sounding alarm=>off: Notify alarm is off All the above should be suppressed for the initial setting of each parameter. I will have to look into metrics to see how best that should be done; one neat way is to keep a modification count (rather than the current m_defined boolean). Does that make sense? Any objections/suggestions? Regards, Mark

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OVMS v3.1 Production Packaging
by Mark Webb-Johnson 25 May '18

25 May '18

Here is the production packaging for the OVMS v3.1 second production batch (and onwards). Inside is foam cut-out, and sized to fit one OVMS module. I haven’t seen it in person (only pictures), but it looks good. Should be less gooey than the bubble protection wrap we used for the first batch. Regards, Mark.

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Early Crash (v.006)
by Greg D. 24 May '18

24 May '18

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HUD Cables
by Mark Webb-Johnson 24 May '18

24 May '18

As discussed, the HUD cables have been produced and seem ok. I received a pair today, hot off the production line in China. Here is the specification: OVMS v3 HUD/OBDII-F Cable One end (DA26-M) connects to the OVMS v3 DIAG (expansion) connector. The other end provides an OBDII female (J1962-F) connector. Cable wiring is as follows: J1962-F DA26-M Signal 4 8 Chassis/Power GND 5 8 Chassis/Power GND 6 16 CAN-H (primary CAN) 14 6 CAN-L (primary CAN) 16 18 +12V Vehicle Power Cable includes a 120ohm resistor between DA26 pins 16 and 6. This provides for an OBDII expansion port for OVMS v3 and allows devices such as OBDII dongles, Heads-up-Displays (HUDs), etc, to be connected to OVMS using the ‘obd2ecu’ firmware module. They look really nice. Moulded, tough, and stubby. DA26 expansion connector to OVMS has screws to hold it in place, and they seem to work well. We had to make a MOQ (minimum order quantity) of 100, and they will go up on Fasttech over the next couple of days (along with stock replenishment for some other cables running low / out of stock). These are relatively expensive to make (moulded DA26 connectors, 120ohm resistor, etc), so will be US$14.50 each (including free shipping). Regards, Mark.

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OVMS hang/crash
by Stephen Casner 22 May '18

22 May '18

I took a three-day road trip to Yosemite this week with the v3.0 module in the car. It seemed to work fine, communicating over the modem except for the spotty reception in the Yosemite Valley due to the high stone cliffs. But back at home, some time after I had plugged in to start charging, the module stopped communicating via modem or wifi. I tried plugging in the USB cable to see what was wrong, but the /dev/tty.SLAB_USBtoUART device did not get created on my laptop so I could not see what went wrong. At that point, I decided I needed to cycle power to reboot, then the module came back up as verified via the home wifi, but the USB was still not responding. Now I have taken the module out of the car and brought it in to connect to the laptop and USB is working again. I guess that must imply that the USB physical connection, although the cable seemed solidly inserted while in the car. I have had the module configured to go to gdb rather than reboot on crashes since that was helpful for development, but I may need to change that setting to use the module in the car. On the other hand, with small RAM of the v3.0 module I don't think I can afford to have the SD card plugged in for logging, so being able to investigate crashes via USB might be best for now if I can figure out why that didn't work this morning. -- Steve

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12v battery alert threshold?
by Greg D. 22 May '18

22 May '18

Hi folks, I'm getting alerts from OVMS that my 12v battery is failing, as it's dropped below the threshold, which is set to 13v for some reason. So I get a notification every time the car transitions from awake to asleep. I don't see a configuration item, nor anything in the OVMS v2 app. Oddly, the threshold is 13.2 for my v3.0 proto module, but I can't find a config item there either. How do I change the threshold? Greg

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