arduino & touchslide

[Jon Wildsmith]

External input connections on my prototype are:

0v / Earth

+12v main battery connection. Feeds ADC channel 0 via a 100k & 39k voltage divider.
+12v aux battery connection. Feeds ADC channel 1 via a 100k & 39k voltage divider.

+12v AUX/IGN connection, wakes up the display when live, feeds pin 3 via a 100k & 39k voltage divider.

+12v LPG / Aux fuel connection, selects L trip when active, feeds pin 4 via a 100k & 39k voltage divider.

+12v Speed sensor connection, feeds pin 2 via a 100k & 39k voltage divider.

4 x +12v sensor channels for temp senders etc, feeding ADC channels 2 through 5 via a 100k & 39k voltage divider.

External output connections:

0v switched output for link 1 (split charge solenoid) driven by a transistor from pin 8.

0v switched output for link 2 (optional 2nd split charge solenoid e.g. DC-DC charger) driven by a transistor from pin 9.

+12v Corrected speed sensor output, driven by a transistor from pin 6.

I'll be back to post again in a bit with a plan for how I think anyone else can get one of these up and running.

 

[Jon Wildsmith]

I won't be buying in the parts for these and turning out finished items, I'm not interested in trying to make money from it and I don't want the hastle of being responsible for faulty parts or whatever, that's a favour too far The way I can see it working for those that are interested is you buy the major components yourself, so that's an Arduino Mega 2560, Touchslide and a Mega Shield. Then you either assemble the Mega Shield interface board following the detailed instructions I'm going to give and program the Arduino & Touchslide (just plug them into a USB port and run some software) with the Hex files I'll also provide, or put them in a jiffy bag and post them to me to have me do those things at your risk If you send them to me there are going to be sundry components and connectors to pay for but ball park is £20 so you can get an idea of total costs.

The interface board will be almost solder by numbers / colours. This is just a sample of what I think will make it accessible to anyone vaguely competent with a soldering iron:

I'll fill in where the components go, e.g. blue is a 100k resistor, yellow is a 39k resistor, green is a link wire, and a couple of other colours for a 1k resistor, transistor (only one type used) etc. Along with photos of a populated board that should be ok to follow if you pay attention?

I could do with getting an idea of genuine interested parties because making it a bit more generic to suit other people is taking up time I could be spending on just suiting myself I don't mean people commiting to going ahead, just is it still something of general interest and is worth me taking the time to make accessible or not?

 

[Gary Stockton]

yes I'm interested thanks Jon

 

[Jon Wildsmith]

I should get chance to try out the speedo correction tomorrow and will report back.

Corrected speed output pulse generation worked in the truck

 

[Justin_Elliott]

Just in case my interest hasn't been clear enough to date... yep I'm in!

 

[Rob]

I may be interested as I will probably be doing a rewire and I think all my design requirements have been met, apart from EGT.

How about exterior temperature? Say if someone did not want auto box temps then would it be possible to wire up an external thermometer? Or an extra channel which can be disabled?

 

[Jon Wildsmith]

Just in case my interest hasn't been clear enough to date... yep I'm in!

Ok, I was counting you as interested

I may be interested as I will probably be doing a rewire and I think all my design requirements have been met, apart from EGT.

Adding EGT is not much different to other temperature senders and is something I'm happy to do if someone lends me an EGT probe for testing. Maybe I wasn't clear about that, I won't be running EGT but that doesn't mean others can't so long as I've had chance to program in the response curve (usually a K type thermo couple) and test it, then it can be selected as the mapping for that channel in the software.

How about exterior temperature?

At the moment I have 4 ADC lines wired to be externaly available and it doesn't much matter what each one is used for just tell the software which curve mapping to use and what label to display for it. There are an additional 9 ADC channels available on the board if you can't cope with only 4 channels so the only limit really is how many wires you're prepared to have 4 temperatures will fit on the display but if we end up wanting additional channels for other things then I'll add a 'sensor' display that's just sensors, a bit like I've done for trip meters. The main display usually shown is just an overview with the most important data shown but there can be lots of other stuff on other UI's.

I've been baking a VDO 0-150c sender in the oven this evening and running back and forth with it so I could test the code I've written for temps All checks out ok so I'll try and start some field testing of that at the weekend. If I had an EGT probe I would bench test for that as well. Now I have some basics in place for temperatures I'll get it written up properly and get the UI finished.

For those playing with circuits (Justin?) I've removed the 100k/39k resistor voltage divider on 2 of the 4 spare ADC channels and have them wired with a 2.7k resistor between the +12v power input and the ADC channel with the temperature sender making up the other half of a voltage divider being between the ADC channel and 0v. That gives < 5v for typical senders and a better range of values / precision on the ADC.

 

[Richard Jackaman]

Jon

I'm interested in the progress that you're making but will probably build my own unit when I make a bit more progress.

At the moment I've managed to identify the speedo output in the wiring loom of the 80 which seems to be on pin 18 of one of the multi-block connectors behind the glove box. Just trying to identify the feed from the coolant temp sender so I can tap that at the same time.

How about exterior temperature? Say if someone did not want auto box temps then would it be possible to wire up an external thermometer? Or an extra channel which can be disabled?

I'm be adding a external temp sender as mine will be on a manual so no atf temps to worry about. Just need to find a suitable spot to mount the sensor, probably somewhere in the front wing unless anybody else has a suggestion.

Cheers

 

[Jon Wildsmith]

Speed sensor output on an 80 is something I can't help with so I'm sure others will be interested to hear more about that I've pretty much decided not to piggy back the OEM coolant temperature sensor and will put a VDO 0-120 sensor in the top hose instead. A bit more generic solution and adds some redundancy

 

[Gav Peter]

I'm sure others will be interested to hear more about that

Kerching!!! Would that be me?? T'would shurely

Any chance of a pic Richard? I am making a speedo correction black box at the moment so this intel would be a time saver if at all possible.

Cheers in advance

 

[Richard Jackaman]

Gav,

This is the connector you're looking for.

I've labelled mine IG-1 so I can find it again. It's behind the glove box and on the 24V the ECU which you can see hanging down in the second pic

This should show the type that you're looking for. Yellow blob is where I traced the connection from the speedo to in the loom.

Not sure if it's the same on all models and I've seen mention that it's on pin1 on some vehicles. The easiest way to check is to disconnect the plug and also the connector on the transfer case and test for connectivity between the 2 points with a meter. After a lot of prodding I got a signal on pin 18. When I reconnected the loom and tapped into the wire I could see a voltage switching when I rolled the truck forwards.

Cheers

 

[Jon Wildsmith]

Fitted the ATF temp sender to my truck and did a bit of field testing this evening, seems to be working well Will give it some longer runs and more testing over the weekend. Alarms and adding coolant monitoring next ...

 

[Jon Wildsmith]

ATF temp reading has been working well, still waiting for some parts to arrive to plumb in for engine coolant temp monitoring. It was tempting to piggy back the OEM senders for ATF and coolant but it's difficult to get an accurate set of data points to calibrate the output with. With after market senders in place I could use those to calibrate readings from the OEM senders but I'm not sure there's much point.

Built a MKII interface board which is better laid out than the first one.

Components and connectors installed:

add links

underneath as well

add an RTC (real time clock) module and stick it in a box

Temp section of the display starting to change with live values

The RTC module is optional but the clock in my truck is obscured by other things and I think I will have other uses for it once the sensor code is all written.

 

[Jon Wildsmith]

A mention in another thread has reminded me to post about the RTC - the one shown turns out not to be very accurate so I removed that and am now using a ChronoDot 2. The temp sensors seem to be working well and I added warning code so it beeps and flashes at you if they go above specified values. There are 2 warning levels per sensor, so you can have a 'start paying attention' level which only beeps twice and a 'oops, better stop now' level that beeps 5 times. There is a UI for setting warning levels. I don't have coolant level sensing resolved yet as in I don't have a physical solution yet. I'm wondering if I can build some logic into the H2O code that will warn about a H2O temperature drop below a specified value once up to normal operating temps. Do temp gauges read low when you run low on coolant (mine is in the top hose) I seem to think they do?

 

[Jon Wildsmith]

The temperature warning code also controls a switched output for turning a fan on so I wired that in today to control the 10" fan in front of the ATF cooler so if it gets a bit hot slogging away at low speeds there is some extra air flow to call on. So far so good, everything has been working as it should.

 

[Jon Wildsmith]

I decided to give the main box some extra ventilation as it lives under the stereo which can get quite hot. I guess I should add an on board temp sensor!

Since I moved my PC monitor I also moved the screen

The features have been frozen for the last few weeks ready for our trip to the Pyrenees but after that I'll be seeing what other tricks it might be good for

 

[Gav Peter]

Yup, looks really neat that Jon Looking forward to staring at it for the next nine days!!!

 

[Jon Wildsmith]

Time I updated this since it's been up and running for a while including the trip to the Pyrenees where most features got used

We had one display lock up early on in France which has been fixed.

The triple beep for the 1st temperature warning level was a bit much and is now a single beep.

The large digit trip meter interface was a bit slow in responding to user input which has been made more responsive and also wired up the remote reset button socket so the navigator can keep the button in their hand.

The corrected speed pulse output wasn't transitioning as smoothly as it should have when looked at carefully on a scope sometimes causing jitter on the car speedo now fixed.

Towards the end of the trip back up through France the LPG/Petrol selection was jumping back and forth, was a bad connection.

Apart from those few glitches it just works

 

[Jon Wildsmith]

Found a smaller case to put the display in

 

[adrianr]

Looks great Jon.