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Twizplay - open source OBD-2 display

Dear Friends of the Twizy!

Maybe someone on this forum can help me. I have constructed an additional display for the Twizy.

It shows the exact state of charge, power consumption in kW, has a Econometer, shows the charging time in minutes, voltages of all 14 cells, smart meters, temperatures, information of driving distance and more.

The name of the additional displays is TWIZPLAY - www.twizplay.de - the website will soon be translated into English language. But not by me, my english is too bad.

The Twizplay is a open source project - anyone can build it. You can order only the circuit board or now there are even ready devices on the market. Just plug and play - must be plugged into the OBD2 port.

The Twizplay gets all data from the CAN bus of the vehicle. And that’s where my problem is. The European version of the Twizy displays km and km/h - the version for England has a mileage gauge and mph.

The European Twizy limited to 80 km/h.

I believe that the data on the CAN bus are the same for both versions of Twizy. The original display expects kilometers to miles. But I do not know it …

My idea is to create a UK version of the Twizplay-firmware. This firmware I had to test with a UK Twizy…

Maybe someone can help me here?

Thank you!

Uwe

Uwe – Let’s talk.

I like Open Source projects and I’m already aware of your project by visiting the Twizy und vectrix forums (although It won’t let me sign up to be a member).

I am more than happy to offer my car as a test platform. However, I am currently without a Twizy. (My first car was crashed :open_mouth: and I am still waiting for the replacement --due next month)

Perhaps I can help then? I am also helping test the OVMS.

Do let me know if you’d like my help.

Nikki.

I also forgot to say…

Another thing I would like to see is the functionality of this transferred to a smart phone. Then you could, for example, take the display with you when parking and nothing visible would be left in the Twizy.

But when you are driving, the phone could charge up and display the extra info also.

Found a Video showing the display working.

[video]http://www.youtube.com/embed/ZgWDoEKstFM?rel=0[/video]

Looks Interesting! :smiley:

Andy

This sounds great, like the smart phone idea, if you could get an app built, then send the info to the phone via an eobd plug in dongle.

Hi Nikki,

“thats a deal” - please write me an email, when your Twizy is repaired. We can try a “Standard” Twizplay - when it shows 80km/h at full speed (= 50 mph) than is there is no problem.

For logging data the OVMS via Internet or with an smartphone-App is the best way.
Using the smartphone as a Car-Display… works not good with direct sunlight…

Uwe

Hi Joggls!
Your product is great. I’m struggling with the German on your website but it looks like I can build the unit from parts I buy from you. Before I saw this I was going to buy a LEM current transducer to make a kW meter. Your software and OBD is much better. I want the kW meter to answer a few questions like - 1. max regen kW (doesn’t seem very high probably to avoid skidding in wet corners), 2. optimum drive speed for range (power increases massively at top speed).
I have a CANBUS ODB lead for VAGCOM (VW AUDI) Do you know if I will I see any useful data if I connect that to the Twizy?

Thanks for your post.
Patrick

Uwe
Just seen this thread and the monitor looks fantastic!
just one point, you say you want to try the monitor on a UK car.
I am having my Twizy delivered in the morning (Cannot wait!) and I have been reading the owners manual online.
One thing I read was that you can put the Twizy Display to read Kilometres from Miles by pressing and holding the end stalk while turning the Ignition on.
Doing the same again changes the display back into Miles.
I would guess that Renault will make all the cars the same for cost reasons so you may be able to test the monitor on your own Twizy. :smiley:
Fingers crossed! :slight_smile:

Andy

Hi Patrick,

yes the max regen is only about 3,8kW - maybe we can change this sometime with new parameters in the secon controller. I think the optimum drive speed depends on many variables - wind - temperature…

With the VAGCOM you can connect the twizy to you pc - the hardware works, but the software you need is different. When there is a function to see all frames - RAW data - maybe that works…

Uwe

Hi Andy,

thats a RTFM Problem - I should read t… f… manual of the twizy! Yes, you are right - now I can test it here - SUPER!

Maybe I can detect the setting of the Twizy by the canbus - than I can change the Twizplay km/m => mph automaticly.

Thanks!

Uwe

Awesome!

Uwe, do you still want UK testers? I am still happy to help, but maybe only when my replacement Twizy arrives (two or three weeks, I think)

I tried to switch my Twizy to mph - nothing happens. OK, it’s written in the instruction manual - maybe my Twizy is too old. So I still need UK testers ;O)

Uwe

Hi I’m also up to help test this. Right up my street. Just let me know.
Chris

**Feature Request
**
Hi Uwe
Does the Monitor have the facilty to tell you the remaining Miles / Kilometres like the Factory display?
The factory display tells lies!
I have been told that the most accurate way of estimating the remaining mileage is to multiply the Number of bars remaining x 4.4 Miles (Summer) or 3.5 Miles (Winter)
Could this be added to the monitor so that users can enter there preferred figure and then calculate the remaining mileage?
With your monitor the software would multiply the charge state by .44 (Summer) or .35 (Winter)

EG
Charge state = 44% x.35 (Winter) = 15.4 Available miles

It would be a lot more accurate than the factory display because you could do the calculation on the actual charge state.
Its a pity that there is no outside temperature monitor then the software could automatically adjust the range according to the outside temperature! :slight_smile:
Hope I have made myself clear!..

Andy

Andy - remaining miles estimate. The bars are indeed the best way and the numbers you quote are pretty spot on. Just need to remember that the bar display updates once every 4.4 miles (summer etc) so if you see 6 bars, it could have just gone down to 6 (26.4 miles left) or just about to go down to 5 (22 miles left) so remember to catch it just changing state for the best estimate.

Andy - remaining miles estimate. The bars are indeed the best way and the numbers you quote are pretty spot on. Just need to remember that the bar display updates once every 4.4 miles (summer etc) so if you see 6 bars, it could have just gone down to 6 (26.4 miles left) or just about to go down to 5 (22 miles left) so remember to catch it just changing state for the best estimate.

Thanks Trevor :slight_smile:
If Uwe was to incorporate the ‘Magic Formula’ into the monitor it would be great!
Being able to use the exact battery charge it would be very accurate! ( I think…)

Andy

I agree the range estimator isn’t very useful, but short of knowing what the rest of your trip is going to be like, and how you plan to drive it, I don’t think it can be. It is based on the remaining battery capacity AND the previous 3km (or something) you have driven. If that has been flogging up a hill at maximum achievable speed, the battery depletion rate will be pretty high and the range estimate will drop. The estimate is fairly heavily damped, and is more inclined to drop than to rise, but I don’t think you can say that you will get 4.4 miles per battery capacity gauge bar in summer, or that it updates the battery capacity gauge every 4.4 miles. I think it it is safe to say that if the rest of your trip is going to be on level ground, and you’re going to be able to maintain a constant speed, then you can assume that you’ll be able to do X miles per bar (5 in my case in the summer, 4 in the winter). I agree that the battery gauge is the only remotely reliable measure we have, but it doesn’t measure range any more than any other fuel gauge.

I was attempting to highlight that the bar gauge only updates every 10% drop and that to use the bars without remembering that 6 bars could mean 59.99% or 50.01% gives you a false sense of remaining capacity.

However if I have been keeping an eye on it and know that I am averaging 4 per bar, every time a bar drops I can estimate myself how far I have left before I panic since the running estimate varies so wildly. I read somewhere it was supposed to be that last 196 km but it changes every 2 - 3 kms or so it appears. Undamped. Well it does on mine.

I was attempting to highlight that the bar gauge only updates every 10% drop and that to use the bars without remembering that 6 bars could mean 59.99% or 50.01% gives you a false sense of remaining capacity

That’s what I was trying to say! :slight_smile:
With the Open Souce OBD-2 Display it could be programmed to do the exact Maths for you.
if there was a parameter screen you could input your preferred measurement.
So in Trevor’s example above working on 4 Miles per Bar for instance.

59.99% Battery Charge x.4 = 24 Miles
50.01% Battery Charge x.4 = 20 miles

The Monitor would show all the miles in between the 5 and 6 bars remaining :slight_smile:
Uwe already has a data reading that tells him the temperature of the batteries.
I wonder if the actual battery temperature is consistant with the temperature outside?
If that is the case then the monitor could be programmed with your preferred Summer and Winter settings.
The Monitor would then adjust the formula in realtime according to the battery temperature :smiley:

Andy

Since the CANbus knows the current charge state of the battery the distance remaining calc could be improved immensely I am confused as to the actual calculation performed. See the reference in the manual

Forecast range display features

– Sporty driving will strongly affect the forecast range value. Once you return to a calmer driving style, you will need to drive for several miles to return to an estimate that is closer to the real situation;
– the forecast range displayed after charging the traction battery is calculated based on the power consumption over the last 93 miles (150 kilometres) travelled.

Based on that, when you have recharged, we should divide the number displayed by 10 to get the miles per bar because as soon as you start driving it is updated with short term effects rather than average. Mine drops from 39 to 25 and back up to 37 by the time I reach town. A meaningless gauge is a useless gauge.