RPM/TPS for non-OBDII cars

[saboteur]

Hi,

I'd like to add RPM/TPS to my datalogs/overlay and have considered building something based on this:
http://asynclabs.com/store?page=shop.pr ... gory_id=11

I was thinking along the lines of running the wireless in IBSS mode, and using some analog inputs to process and format the data then make it available via the wifi interface.

Do you think the best idea is to simulate one of the already supported OBDII wifi devices? I assume it is up to the iPhone to poll the device and not the other way around?

Any examples of the protocol would be a huge time saver.

Cheers

[saboteur]

You mentioned that the ELM327 is supported, so I have been reading the datasheet for it. I have set up a simple TCP listener on my workstation and set the IP and port under advanced settings so I can see how your program talks to it. So far I can just see that it sends a AT reset upon connection. If you can let me know what commands must be implemented, that would be a great help.

Cheers

[Harry]

Hi,

I think a lot of drivers with older cars will love this idea. The ELM327 protocol requires a continuos dialog between the requester and the ELM side. LapTimer certainly requests more than TPS and RPM. However, to make these two work in the beginning, the following EML327 commands need to be answered:

"ATZ\r" -> ignore but answer with at least "\r>"
"ATWS\r" -> ignore but answer with at least "\r>"
"ATE0\r" -> ignore but answer with at least "\r>"
"0100 2\r" -> needs to answer that TPS and RPM are supported but nothing else
"010c 1\r" -> RPM
"0111 1\r" -> TPS

In case you need further support, contact me at LapTimer@gmx.de

- Harry

[bulls23]

Hi,

I'd like to add RPM/TPS to my datalogs/overlay and have considered building something based on this:
http://asynclabs.com/store?page=shop.pr ... gory_id=11

I was thinking along the lines of running the wireless in IBSS mode, and using some analog inputs to process and format the data then make it available via the wifi interface.

Do you think the best idea is to simulate one of the already supported OBDII wifi devices? I assume it is up to the iPhone to poll the device and not the other way around?

Any examples of the protocol would be a huge time saver.

Cheers

This sounds veeeeeeeery nice I'm one of those users who's desperately looking for a solution for older non OBDII cars.
Could you elaborate a little bit further on your idea / approach? How would that module be connected to the car? Would it work for any car? How high could the update rate be?
Lots of questions from a OBD noob...

[bulls23]

I know im a pain in the a.. but is there any news on this?

[loftygoals]

I know the Kiwi Wifi also has a version that support the serial sensor connections.

Being that HLT already communicates to the device, could this information be monitored as well?

If so, could it be possible to simple use an odb2 connector to supply power and ground to the Kiwi Wifi unit and then only poll of the external sensors on non-OBD2 cars?

If this would work, it would create minimal coding changes and offer a lot of monitoring options to both OBD2 and Non-OBD2 users.

-bj

[saboteur]

Sorry guys I've been really busy and haven't made much progression with this. I have, however, found an alternative to the discontinued item I linked to above. I'll be ordering one of these in the near future:
http://www.linksprite.com/product/showp ... g=en&id=75

With Harry's input above I will now start working on a test program to ensure I have the protocol working well enough.

Cheers

[bulls23]

I know the Kiwi Wifi also has a version that support the serial sensor connections.

Being that HLT already communicates to the device, could this information be monitored as well?

If so, could it be possible to simple use an odb2 connector to supply power and ground to the Kiwi Wifi unit and then only poll of the external sensors on non-OBD2 cars?

If this would work, it would create minimal coding changes and offer a lot of monitoring options to both OBD2 and Non-OBD2 users.

-bj

This sounds like a pretty good idea too...but are there any sensors available for RPM, TPS etc. ? Couldn't find them here: http://www.plxdevices.com/sensormodules.html
The only down side would be the costs involved (PLX Kiwi Wifi + additinal sensors).

[perelet]

Harry, I use this accessory -

http://www.oscium.com/products/mixed-si ... e-imso-104

This is digital & analogue oscilloscope for iphone/ipad. I can easily pick up digital tachometer signal from obd1 on my 90 Porsche 964.

Oscium scope has 4 digital (0-7v) and one analog (-40v-40v) that is plenty signas that can be used.

I do not know how hard it is, but if you can interface to that - it will be priceless.

Thanks.
Oleg.

[Harry]

Interesting product. However, this would mean I need to interpret arbitrary electric signals. Even if these guys offer an open API I can use, and I get insights how to come from some of this signals to a reasonable car parameter, this would get a support nightmare

- Harry