Controlling an analog dash

[clanger9]

With the power on, but the gauge input disconnected, try putting a 1k pull-up resistor between the gauge input terminal and +12v.
Does the gauge then return to zero?

[Greenbeast]

Thanks clanger i will hopefully have a play with that this evening, and see if i get the same result as arber.

I think i need to improve my work bench setup, it's extremely Heath Robinson and not very conducive to good testing

[arber333]

I found an old schematic for my Mazda dial. It worked... I have to find one mosfet to tesxt this here...
See if you can get it to work.

[Greenbeast]

With the power on, but the gauge input disconnected, try putting a 1k pull-up resistor between the gauge input terminal and +12v.
Does the gauge then return to zero?

Sorry, this does not appear to work.

I found an old schematic for my Mazda dial. It worked... I have to find one mosfet to tesxt this here...
See if you can get it to work.

My gauge has +12V, GND and sender input, how should i interpret your diagram, should i assume the GND is a given, and connect it that way?
Is Q1 the mosfet?

[clanger9]

When does the gauge go back down? Only when you disconnect the 12v supply?

[arber333]

My gauge has +12V, GND and sender input, how should i interpret your diagram, should i assume the GND is a given, and connect it that way?
Is Q1 the mosfet?

GND is anywhere on the car i think. But you need 1K pullup for gate to invert signal and resistance toward GND so mosfet will pull signal down and release it in between pulses. What is your dial resistance on full and on empty?

A

[Greenbeast]

When does the gauge go back down? Only when you disconnect the 12v supply?

Currently never, it stays up unpowered.

[Greenbeast]

My gauge has +12V, GND and sender input, how should i interpret your diagram, should i assume the GND is a given, and connect it that way?
Is Q1 the mosfet?

GND is anywhere on the car i think. But you need 1K pullup for gate to invert signal and resistance toward GND so mosfet will pull signal down and release it in between pulses. What is your dial resistance on full and on empty?

A

OK that doesn't mean much to me (I'm a relative novice).
I will check the service manual tomorrow to see if it details that. It shows the sender as 1-5Ohm full 104-117Ohm half full but oddly doesn't show the empty value, unless there's been a misprint (check my post on page 1)

[arber333]

Currently never, it stays up unpowered.

Hm... maybe there is damage to its internal circuit. Can you take the dash out and try to use the dial as ammeter? To confirm it still works?

[arber333]

OK that doesn't mean much to me (I'm a relative novice).
I will check the service manual tomorrow to see if it details that. It shows the sender as 1-5Ohm full 104-117Ohm half full but oddly doesn't show the empty value, unless there's been a misprint (check my post on page 1)

What car is this? European cars usualy have value somewhere around 10R(empty) 190R(full); US 240(empty) 30(full).

[Greenbeast]

Daihatsu Fourtrak, Japanese

[Greenbeast]

Currently never, it stays up unpowered.

Hm... maybe there is damage to its internal circuit. Can you take the dash out and try to use the dial as ammeter? To confirm it still works?

That is entirely possible, i may have been a bit slap dash in my connecting and trying things out. Some of my warning lights don't work either now.
Thankfully this is a spare cluster

[arber333]

I have Mazda mx3 and it is in reverse of my EU Peugeot 406.
You should get a reaction if you connect 150R from signal towards GND.
Also verify if there is a fuse in that circuit. Maybe it is blown?

[Greenbeast]

Ah, the mazda would be likely to match it i guess.

I can't see a fuse on the 'board', so unless it's inside the cluster i don't know.

Didn't have 150R, only a 91R, which did nothing. I need to get a few more components into stock

[Greenbeast]

I tested the resistance across the terminals as suggested by the service manual and it reads higher than it should (70-80R, as opposed to 55R), the temp gauge reads correctly.

[Alibro]

I just found this thread and I suspect it will be gold dust for me in the future so many thanks to all who have shared here. Very much appreciated.

[Greenbeast]

I haven't pursued this much recently. Life got in the way. I was trying to set up a better bench rig for it. Breaking out the wires to a set of labelled screw terminals for easy testing, rather than a jumble of wires and loose crocodile clips

[mackoffgrid]

This is my solution to drive the instrument cluster in my ute conversion.

https://github.com/mackelec/SolarUte/tr ... s/CANio-18

It is all CAN bus driven - stm32Duino. It will drive the Temperature and Fuel gauges, various dash lights. The tacho is PWM driven (specific to the B2500 ute).

[clanger9]

Very nice! I may well use this for my bike project.

[Greenbeast]

Wow that looks cool! Thanks

Do you have any video content of this in situ working

[mackoffgrid]

Thanks.
I've not done any videos - Never mind Cecil B Demille, I'm no Damian when it comes to video making
I'll see what I can do.

We're pretty slow in our project and while I made this board some time ago it's only now about to go into the car .

[clanger9]

My mind is blown by JLCPCB.

Literally: I just load those files in, click "SMT assembly", pay around $70 and I get 5x assembled boards in the post a few days later?
Is it really that simple?? That is incredible.

[Greenbeast]

Does seem pretty cool.

I dare say i might take one off your hands at some point in the future

[mackoffgrid]

My mind is blown by JLCPCB.

Literally: I just load those files in, click "SMT assembly", pay around $70 and I get 5x assembled boards in the post a few days later?
Is it really that simple?? That is incredible.

I've been designing and drawing PCB's since crepe tape days JLCPCB is truly remarkable from my perceptive.

I am now using their CAD, design a board, press a few buttons and a week later a man in a yellow van gives me assembled PCBs - Fantastic.
With some luck, Star Trek is our future !!!

[clanger9]

Yep, last time I made a board it was paper tape, dunked in ferric chloride then hand-drilled. I had no idea that SMT boards were accessible to mere mortals. This changes *everything*