kyteler Posted June 23, 2013 Share Posted June 23, 2013 Sweet , that section at the top of the a pillar looked concerning, glad it was just terrible filler work. Quote Link to comment Share on other sites More sharing options...
snapper Posted June 23, 2013 Share Posted June 23, 2013 so whats next, the salt and beer treatment? Quote Link to comment Share on other sites More sharing options...
mikey Posted June 23, 2013 Author Share Posted June 23, 2013 Sweet , that section at the top of the a pillar looked concerning, glad it was just terrible filler work. Yeah, for reals. I was a widdle bit nervous about that too. so whats next, the salt and beer treatment? haha. It goes in for paint on the 1st of July. In the meantime I'm getting the seats reupholstered and dash recovered and a few other interior bits and pieces sorted. I'm also looking at installing a HVAC from a pick-a-part car including AC, thinking old honda civic or sommin. Quote Link to comment Share on other sites More sharing options...
coldturkey Posted June 23, 2013 Share Posted June 23, 2013 Mikey, explain to me what you are doing and what that oscilliscope output is showing. I may be able to help. Does your circuit convert a sine wave to a squarish wave to be read by a microcontroller and then output a true square wave? Quote Link to comment Share on other sites More sharing options...
mikey Posted June 23, 2013 Author Share Posted June 23, 2013 Mikey, explain to me what you are doing and what that oscilliscope output is showing. I may be able to help. Does your circuit convert a sine wave to a squarish wave to be read by a microcontroller and then output a true square wave? The scope is showing the output from 3 ignition drivers passed through steering diodes. Which I was then feeding into this circuit http://www.dinoplex.org/tachoconversion/ But for some reason there's no output from the CD14538BE. I'm fairly sure the circuit used to work when hooked up to one ignition signal i.e without the steering diodes It's possible I've fucked it as I've been hacking it quite a bit. I've had a good look over it and can't see anything physically wrong with it, and I've tried a new IC. Maybe I should isolate the output line from the IC and check it when it's not hooked up to the transistor etc, just incase the transistor's blown and it's pulling the output low? Any help greatly appreciated! Quote Link to comment Share on other sites More sharing options...
coldturkey Posted June 23, 2013 Share Posted June 23, 2013 yeah, since you have a scope, leave everything connected (how you think it should be). What does the output of your voltage regulator look like (while running)? After that disconnect the stuff coming off the IC, and what do you get on the output directly off the IC? Quote Link to comment Share on other sites More sharing options...
mikey Posted June 23, 2013 Author Share Posted June 23, 2013 yeah, since you have a scope, leave everything connected (how you think it should be). What does the output of your voltage regulator look like (while running)? After that disconnect the stuff coming off the IC, and what do you get on the output directly off the IC? The output from the voltage Reg looks good, 8V or so from memory. I'll test the IC output tonight and report back. Quote Link to comment Share on other sites More sharing options...
coldturkey Posted June 23, 2013 Share Posted June 23, 2013 yeah but is it a steady signal, i.e. is something pulling it down when the chip triggers Quote Link to comment Share on other sites More sharing options...
mikey Posted June 23, 2013 Author Share Posted June 23, 2013 Ahhh, good thinking. Will check that. Quote Link to comment Share on other sites More sharing options...
Ned Posted June 23, 2013 Share Posted June 23, 2013 Hey Mikey, i'm happy to help out with electronics bits and pieces if you like. I'm not the most skilled hardware person, but can work my way around most things. I had a quick look around the schematic, and it's drawn a bit weird/difficult, but it looks like you have 12V and ground and a signal wire going in, and then you have 2 output wires that go to the tacho, which are continuous 8V and the other wire switches down to ground for a set time period with a pot in line with it to set the current going through the tacho at every input trigger? Looks simple enough to diagnose if you want a hand one day? Mark 10-5 made the old version of it that worked well. It uses a ATtiny13 instead of that monostable multivibrator. May be worth looking into instead? I have the programmer available still if you want me to program the chip for you and just copy 10-5? though i'm, not 100% sure on what you're using for the input etc but that can all be sorted, surely... What are you doing speedo wise? edit; heres 10-5s setup; //oldschool.co.nz/index.php?/topic/23498-marks-datsun-240k/?p=916803 edit2; i just found the source code for the old version as well as the hex file with the same firmware 10-5 runs Quote Link to comment Share on other sites More sharing options...
snapper Posted June 23, 2013 Share Posted June 23, 2013 so what sort of colour are you going for Mikey? I wasn't expecting something as fine as this to be sacrificed to beer and salt... Quote Link to comment Share on other sites More sharing options...
mikey Posted June 23, 2013 Author Share Posted June 23, 2013 Hey Mikey, i'm happy to help out with electronics bits and pieces if you like. I'm not the most skilled hardware person, but can work my way around most things. I had a quick look around the schematic, and it's drawn a bit weird/difficult, but it looks like you have 12V and ground and a signal wire going in, and then you have 2 output wires that go to the tacho, which are continuous 8V and the other wire switches down to ground for a set time period with a pot in line with it to set the current going through the tacho at every input trigger? Looks simple enough to diagnose if you want a hand one day? Mark 10-5 made the old version of it that worked well. It uses a ATtiny13 instead of that monostable multivibrator. May be worth looking into instead? I have the programmer available still if you want me to program the chip for you and just copy 10-5? though i'm, not 100% sure on what you're using for the input etc but that can all be sorted, surely... What are you doing speedo wise? edit; heres 10-5s setup; //oldschool.co.nz/index.php?/topic/23498-marks-datsun-240k/?p=916803 edit2; i just found the source code for the old version as well as the hex file with the same firmware 10-5 runs Thanks, I could do with a hand actually. I'm a bit over my head. I'll do these checks tonight and see where we stand. But some help with it would be greatly appreciated. I'm hoping to get it working before the car goes to paint next week. I was planning on doing the same as 10-5 actually, but then I saw they'd changed to this schematic so thought I'd do this. I'll give this a bit more of a go and see how we go. so what sort of colour are you going for Mikey? I wasn't expecting something as fine as this to be sacrificed to beer and salt... I planning on sticking with the red, but I can't say I'm 100% sure it's the right thing to do. I'm pretty fond of this color: One issue with changing colours is I've already painted the engine bay red. So I'm 95% sure I'm going with this scheme: I don't have a g-nose obviously, but satin grey flares, bumpers & wheels. Quote Link to comment Share on other sites More sharing options...
Snoozin Posted June 24, 2013 Share Posted June 24, 2013 Grey with charcoal flares might look a little too similar to another Z The original red with the charcoal flares is a classic though, I do like it. 1 Quote Link to comment Share on other sites More sharing options...
mikey Posted June 24, 2013 Author Share Posted June 24, 2013 Grey with charcoal flares might look a little too similar to another Z The original red with the charcoal flares is a classic though, I do like it. Yeah, people with think I copied or sommin! Also, red means I can still join the Red Datsun club. 1 Quote Link to comment Share on other sites More sharing options...
Ned Posted June 25, 2013 Share Posted June 25, 2013 Still have no idea why that circuit wouldnt work with an input below 3V9 I found the schematic for the micro version for you; The wayback machine found it http://web.archive.org/web/20101114225751/http://www.dinoplex.org/tachoconversion/ Quote Link to comment Share on other sites More sharing options...
mikey Posted June 26, 2013 Author Share Posted June 26, 2013 Sweet, I'll get to work on it in the next couple of weeks. Thanks again for help with the debugging. Quote Link to comment Share on other sites More sharing options...
ProZac Posted June 27, 2013 Share Posted June 27, 2013 Hrmmmm. Maybe that needle motor driver thingee you built is busted? from what I can see, it should certainly work with that input. If I were you, I'd put the 240z tacho back to stock, and check it works off an inductive spike as per normal. Then trace the input signal line on the stock tacho PCB to the first resistor in-line. Solder a jumper across it. This eliminates this dropping resistor, and should allow the original tach to be driven from a 12v square wave. Then slap together a level shifter to shift your ~4v ignition signals (after the steering diodes) to 12V, and go from there? Hell, send me a stock 240 tacho, i'll do the work, test it, and send it back to you ready to hook up to your steering diode outputs. Quote Link to comment Share on other sites More sharing options...
mikey Posted July 4, 2013 Author Share Posted July 4, 2013 Hrmmmm. Maybe that needle motor driver thingee you built is busted? from what I can see, it should certainly work with that input. If I were you, I'd put the 240z tacho back to stock, and check it works off an inductive spike as per normal. Then trace the input signal line on the stock tacho PCB to the first resistor in-line. Solder a jumper across it. This eliminates this dropping resistor, and should allow the original tach to be driven from a 12v square wave. Then slap together a level shifter to shift your ~4v ignition signals (after the steering diodes) to 12V, and go from there? Hell, send me a stock 240 tacho, i'll do the work, test it, and send it back to you ready to hook up to your steering diode outputs. The circuit I built all works, surprisingly! I took it to Ned's place of work and he hooked it up to a signal generator and it all went fine. So the question was, why doesn't it work in the car? Turns out the ignition signal to the coils is about 4V1, and the tacho circuit wont work on anything less than 3V9. After the steering diodes the voltage must be dropping below this. The current plan is to build the totally different circuit in the schematic above with the Microcontroller. However couldn't I just use a transistor on the IC input and VDD to step the input voltage up? Quote Link to comment Share on other sites More sharing options...
Ned Posted July 4, 2013 Share Posted July 4, 2013 You sure could, yeah. Just need a transistor and a couple resistors and that will work too. Quote Link to comment Share on other sites More sharing options...
mikey Posted July 4, 2013 Author Share Posted July 4, 2013 Would I do something like the following? With the 8V VDD tied to the voltage reg. Or am I safest to have a current limiting resistor between the transistor and the IC? Quote Link to comment Share on other sites More sharing options...
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