Outside temperature weirdness

[teamster1975]

Hey Everyone
My car has decided that it's summertime, it was 18c when we had snow last week!
The temperature starts off correct but as soon as you switch on the ignition global warming ensues
Is it just a duff thermistor or could the trip computer be up the swannee?
Cheers,
Matt

[mjb]

Damn good question. I can't say owt about D9s (you didn't say what you've got) but on the D8 you're quite possibly looking at a visit to ebay for a new trip comp. Can't hurt to grab a new thermistor though, I think they're only a couple of quid from the dealers - check on http://public.servicebox.peugeot.com - and they just go in the passenger wingmirror.

[djp30djp]

One of mine has started reading about 25* lower than it is but it still changes with the air temp, I have ordered the part at a cost of £12 from dealer.

[teamster1975]

Cheers guys. It is a D8, I've got a spare computer lurking around somewhere, just need the sensor.
Actually it's not a bad thing, it'll spur me into installing the trip wiring, although I may have a heart attack when I see the economy of my 2l tubby

[mjb]

Cheers guys. It is a D8, I've got a spare computer lurking around somewhere, just need the sensor.
Actually it's not a bad thing, it'll spur me into installing the trip wiring, although I may have a heart attack when I see the economy of my 2l tubby

Keep reminding me and I'll get round to doing my visual howto on the trip computer soon

The tubby's a strange beast though. If you do 60mph down the motorway you can get up to 50mpg. Start having fun and feeling that 3-4000rpm rush, it'll easily deliver well under 15mpg AVERAGE


Actually I've been thinking about my custom trip computer project recently since I've found out a fair bit about the VAN bus the ECU uses to speak to the trip comp. I'm going to make up a multi-channel 2MHz data logger at the weekend to see if I can extract and decode the Good Stuff. Found a nice microprocessor and LCD too. Watch this space!

[teamster1975]

I remember the fun fitting it to my LX. I was chuffed with the result though! At least the exec already has the temp sensor plumbed in! I've still got my spare connector for the extra row of pins, just got to connect it all up.

Actually I've been thinking about my custom trip computer project recently since I've found out a fair bit about the VAN bus the ECU uses to speak to the trip comp. I'm going to make up a multi-channel 2MHz data logger at the weekend to see if I can extract and decode the Good Stuff. Found a nice microprocessor and LCD too. Watch this space!

Keep us posted! I like my gadgets!

[mjb]

I've still got my spare connector for the extra row of pins, just got to connect it all up.

Jammy sod!!! Where did you acquire that from? I built a DB9 connector into mine and made a mini loom to go to the dash.

Keep us posted! I like my gadgets!

Here's the kind of thing I've got in mind:

* Colour graphical screen (might just use a breakers yard/ebay D9 display if I can't find something better)
* 60MHz ARM7 powered LPC2148
* flash upgradeable firmware
* usual trip computer functions - mpg, mph, etc
* fuel consumption calibration (work it out from between brimmings and tell it what you've really used for better accuracy)
* extra data if available (rpm, throttle position, etc if the ECU will let me have it)
* data logging
* realtime/offline output to a PC to let you see your speed/mpg plotted on a chart or map
* possibly bluetooth connectivity, which'd also let me speak to a GPS receiver
* battery backup

I've even been thinking about really extending the project and building it with a touchscreen Sony PSP display, usb hdd connectivity, mp3 decoding and audio line-out. That'll definitely be a mk.2 design though ;)

But this all hinges on whether I can 1) read 2) decode and 3) reverse-engineer the VAN bus protocol. That'll be the hard part.

[mbell666]

Not planning much then!!!! Reverse engineering the bus sounds like fun, not!!!

You planing on making your own circuit board or just using an off the shelf prototyping board?

* 60MHz ARM7 powered LPC2148

Reminds me of the washing machine project i did at uni (and various courses since), probably the most interesting thing i did at uni.

[teamster1975]

Jammy sod!!! Where did you acquire that from?

Just from a breakers. I popped out the tray that blanks off the trip computer from a wrecked LX and chopped the connector off. You can prise off the top of the connector and add new wires to it, then I put it in a mini g clamp to crimp it all together. If you cut the bottom lugs off you're existing plug you can actually slot the two together to make a single connector in effect.

I'm liking the sound of this in car computer mjb!

[mjb]

Not planning much then!!!!

Features are easy. It's getting a working base setup (with VAN decoding) that's going to be the killer. I'm still half considering taking the easy way out and getting a more powerful microcontroller I can run a netbsd/linux kernel on.

Reverse engineering the bus sounds like fun, not!!!

I've still got to figure out how to write something to take in 2MHz digital samples and shrink it down to a 125kbit/s bitstream.

You planing on making your own circuit board or just using an off the shelf prototyping board?

I should be able to do it easily on some stripboard, but I'll probably end up using a chopped up pre-built header board for the microcontroller. I haven't got a clue how to practically make PCBs, especially not well enough to support SMD chips...

[steve_earwig]

Fantastic! Can one of you two come round here and program my video?

[mjb]

Fantastic! Can one of you two come round here and program my video?

If it's "user friendly", no ;)

[teamster1975]

If it's "user friendly", no ;)

Ah, videoplus; supposed to make life easy

[steve_earwig]

I had that, never had a problem with it.

Here there's only one safe way of taping anything: wait 'til it comes on a hit record. And pray they didn't cut half of it out to cram more adverts in again

Still, at least most english language programs have subtitles here, unlike Poland where they have some bored sounding guy reading the script out in Polish

Sorry, what was the subject? Ah, outside temperature. It's now a heady +2 here, pass the tanning butter.

[mbell666]

Features are easy. It's getting a working base setup (with VAN decoding) that's going to be the killer. I'm still half considering taking the easy way out and getting a more powerful microcontroller I can run a netbsd/linux kernel on.

I suppose whether a using Linux or other OS will depend depend on what hardware you use. If you can find displays with appropriate drivers for the OS, it'll probably a good move. v2 with MP3 decode and audio it will probably make your life a lot easier, should just be able to download an open source app and tweak it to work with the controls your providing.

I'd guess there not much price difference between a low end controller (e.g. ARM7) and something you can run Linux on (e.g. ARM926) and on a project like the effort saving will far out way the extra cost. Unless you really do like a challenge that is....