OBD Update Rates with KiwiWifi

Discussion related to external OBD and other sensors
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Harry
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Re: OBD Update Rates with KiwiWifi

Post by Harry »

Hi,

The Kiwi is a little slower than e.g. the OBDLink. That is not in the range you name, so this is not reason for your observation. The update rate depends a lot on the implementation of the car's bus. For Porsches, the update rates have increased significantly since the beginning of their CAN implementation. Looking into the benchmarks (first post in this thread), it seems the Spider has an older bus implementation - not the same as the 911.

Today, LapTimer does not access the CAN protocol directly, so it is not highly optimized and will not deliver max rates. Instead it uses the standard OBD PID logic - which is compatible to a wider range of cars.

- Harry
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Gernby
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Re: OBD Update Rates with KiwiWifi

Post by Gernby »

orthojoe wrote:I get 3hz on my 2008 Mitsubishi evolution X, and 3hz on my 2011 Porsche Boxster Spyder.

Both of these cars use CAN bus protocol. From my understanding, CAN bus protocol should be able to output 20-40hz. Is the slower update a limitation of the kiwi wifi or the iphone?
Not to take the thread off-topic, but I wanted to answer this question about the lower rates via WiFi. My S2000 gets about 10 Hz using HLT with my Kiwi Wifi, but when I use a wired CAN dongle and custom desktop app, I can get 200 OBD query / responses per second, with total frame rates exceeding 2000 frames per second (live stream, queries, and responses).
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Harry
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Re: OBD Update Rates with KiwiWifi

Post by Harry »

I assume it is both, CAN direct access, and wireless vs. wired. The later adds quite some latency for each ping / pong.

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tipounastre
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Re: OBD Update Rates with KiwiWifi

Post by tipounastre »

Hi Harry,

I have just received my PLX Kiwi Wifi today - on an Audi RS4 B7 (V8) from 2006: 8.4 Hz

Kind regards,
Jerome
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Re: OBD Update Rates with KiwiWifi

Post by tipounastre »

Same KiWi - new car: Audi TT RS 2010 = 8.1 Hz
Amnizu
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Re: OBD Update Rates with KiwiWifi

Post by Amnizu »

I will post my Rate from my '08 Subaru WRX tomorrow. One question however, I have a Cobb AP and there is a wealth of other data available to log through my ODBII port that is presently ignored by the lap timer. Would it be possible to log this into a straight data dump for external usage in race render? Also, i have noticed that the data sample frequency is fairly slow, especially in autocross where you're on very short bursts of throttle.

Things like boost, MAF, Gear (non calculated) and Wastegate duty are very useful on a turbo charged car.

Here is a list of all the data that is available via my ODBII port after the install of the cobb AP.

http://www.cobbtuning.com/Subaru-Access ... nitors-wrx

Thanks much!
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Harry
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Re: OBD Update Rates with KiwiWifi

Post by Harry »

Hi,

I do not see I can manufacturer specific data in the short term. You need to get your hands on the data (which typically costs a wealth of license fees), and - there are quite some manufacturers and cars out there ;-) So I need to focus on the standardized ids currently.

- Harry
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lisocayman
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Re: OBD Update Rates with KiwiWifi

Post by lisocayman »

Could someone post a picture of the realtime coolant/oil temperature? I'm curious to see how large and readable this is on track. I haven't purchased an OBDII adapter yet but I'm thinking this might be a good option to view the correct data on a Cayman S, the stock gauge is useless.

Thanks
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OBD Update Rates with KiwiWifi

Post by Harry »

The gauge is not large, it is the same size as e.g. the GPS Rate in LT's GPS View. Please note that most cars do not deliver oil temp through the standard OBD PID. The 997 series of Porsche e.g. do not (they deliver coolant temp only).

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OBD Update Rates with KiwiWifi

Post by lisocayman »

Thanks Harry. I can see my oil temp with my durametrics cable on my gen 1 cayman S, can you see yours on the 997?

Any chance you're thinking about a critical data screen that has larger dials?
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