One-touch turn signal modification

[agg32]

Revtor, thank you for your clarification. Do you have any suggestions for incorporating the hazard function? Can I pull IN_RIGHT and IN_LEFT to ground at the same time via a d/p relay driven from the hazard switch for example?

Many thanks.

[revtor]

No, you cannot. The software does not allow both outputs to be active at the same time - this is an invalid situation in all cars. The OTTS module just emulates the turn signal switch. When you tap the lever, it's as if someone else is holding the lever just a little longer to complete the three blinks.

I don't know how the hazard switch is wired in your car, but normally the OTTS module should not affect its functioning. If the hazard switch is currently bridged over the turn signal switch, it should be bridged over the switch and OTTS module after the modification (over the common contact of the switch and the outputs of the OTTS module).

[agg32]

Revtor, thank you for your help. I'm familiar with the basic function of comfort blinkers as I have something similar in my Mercedes. I was just having a senior moment with your implementation!

Many thanks.

[powerca]

@Revtor, can you send me PCB layout for module based on two 555 timers?
Here's my email: g1.kramberger(@)gmail.com

[koliva]

Hello,

I have just seen your amazing implementation. I have a peugeot 307 and I am planning to build the one with microcontroller. I need to check now which version I need to follow. PN, P, N, NN, NP? Thank you very much.

[koliva]

Hi Revtor,

I have tried to send you PM but couldn't succeed.
Although the ATtiny24-20PU costs almost nothing, the development-programming board costs around 50 euro, which is not so expensive but if you will use it to build only this circuit then it is expensive. I am wondering if you can program it and send me by post by mail since I am also living in Belgium. I can send the money that you ask beforehand to you account. No problem. I am waiting for your positive or negative reply.
Thanks.

[koliva]

You have got an e-mail

[cvhuis]

Hallo Revtor,

I build your 555 comfort switch, but when i installed it in my z3 it works not completely for me. When I blink short then everything works fine, but when
the blinkswitch is pulled back by the steerwheel, the other side is triggered.
So i suppose when the switch is pulled to zero by the steerwheel, it makes a short contact on te oppostie switch.
Can I delay the trigger input so this wil solve the problem?

[revtor]

cvhuis: The 555-based one-touch turn signal module is outdated and I do no longer recommend to build it because it lacks the flexibility of the later microcontroller-based versions. The issue you describe can easily be resolved in the microcontroller-based versions by increasing the debouncing time (DEBOUNCE_LOOPS).

The E36 turn signal switch is very similar to that of the E31 and I never experienced your issue. Are you sure the switch is still ok? Anyway, normally this can be fixed by adding a simple RC filter to each input. The difficulty here is that the inputs also control the other timer's reset signal: The reset signal needs to be a pulse. That's what the edge detectors (R1/C1, R5/C2) do. These are somewhat of an afterthought - a quick and dirty fix - because I had completely forgotten the 555's cannot trigger when the reset signals are low. I'm afraid the edge detectors might not work properly with RC filters attached... I no longer have the version 1 circuit, so I can't do some quick experiments for you, but I would try as follows: Replace R1 (1M) with a 10k resistor. Put a 10µ electrolytic capacitor (Cx) parallel over R1 (negative terminal to ground). Put another 10k resistor (Rx) between the R1-C1-Cx joint and LEFT. Do the same for the right channel. If the circuit still shows the faulty behavior, try increasing the value of Rx and/or Cx. If the circuit no longer works with the RC filter in place, try increasing the value of C1 and C2 (eg 100n). If things just won't work, sorry, but the circuit was never designed with this issue in mind and I don't have the time to redesign a proper working input. Since you are from the Netherlands according to your profile, you might want to join the circuitsonline.nl forum and ask for thoughts about redesigning the circuit's input.

Personally I would recommend to build the microcontroller-based version instead or if you prefer a pre-assembled version, get the jalt.de KomfortBlinker.

[cvhuis]

Thanks for the quick response, i indeed post the circuit in the forum of circuitsonline.net.

I would like to build the microcontroller version, but have no possibility to program it, it's cost to much to buy this for this occasion.

So, for this moment i have no time to try something on the circuit, i have to go with the car on a holiday.

I wil think about the next step to make.

[brolism]

Hi revtor, i want to make pcb with 555 timers. Can you send me yours pcb layout?

[revtor]

brolism: I don't have a PCB layout for the first version of the one-touch turn signal (OTTS) module. I started working on the second version before I got to drawing it. If you are interested, I can send you high resolution pictures that should enable you to reproduce the board. Drop me a mail at and I'll send you the pictures.

Personally I would recommend to build the second or third version, derivates from it, or get the jalt.de version instead.

[CaifanSC]

I just drove a newer 3 series and now I know what this one-touch function is all about. I'm curious tho...if I recall correctly the lever on the newer cars automatically goes back to the "center" position...where as on our 8's when you push the lever down it stays down unless you physically change the position back to the center.

With this one-touch module on the 8..i guess it's on the driver to simply move the lever down enough to activate the signal, but, not enough to hear the "click" which makes the lever stay in the down or up position, correct?

[revtor]

With this one-touch module on the 8..i guess it's on the driver to simply move the lever down enough to activate the signal, but, not enough to hear the "click" which makes the lever stay in the down or up position, correct?

Exactly. Actually the E31 turn signal switch already has two stages in each direction (slight press for flashing without detention, press further for detention). However, a short tap on the lever only flashes the turn signals for that short moment. There is no minimum blink count as found in modern cars... That's what this module is about.

[Keith1054]

Bumping this way up.
I would like to make one of these for my 1997 e36 M3 since the jalt.de Komfortblinker webiste is down. Has anyone successfully installed one on this chassis? I'm not affraid to solder up the board, but is there anyone in the U.S. that could program the microprocessor for me? I don't want to buy the programmer just for this.

Also, is there any videos of the tripple blink in action? I just want to check out how smooth the operation is.
Thanks!

[M3C]

Bumping this way up.
I would like to make one of these for my 1997 e36 M3 since the jalt.de Komfortblinker webiste is down. Has anyone successfully installed one on this chassis? I'm not affraid to solder up the board, but is there anyone in the U.S. that could program the microprocessor for me? I don't want to buy the programmer just for this.

Also, is there any videos of the tripple blink in action? I just want to check out how smooth the operation is.
Thanks!

As E36 M3 owner I have successfully installed one from jalt few years ago and it works perfect.

[revtor]

I would like to make one of these for my 1997 e36 M3 since the jalt.de Komfortblinker webiste is down. Has anyone successfully installed one on this chassis?

The turn signal wiring of the E36 is pretty much the same as that of the E31, so no worries there. The OTTS module, however, does require feedback from the blinker relay. In the E31 the blinker relay outputs are relatively easy accessible in the left footwell wiring harness. You'll have to look at the E36 diagrams to find similar splice points. The jalt.de module does not require feedback from the blinker relay.

The current OTTS module is actually somewhat overkill. It was designed to be compatible with many different blinker systems and hence features powerful MOSFET switches whereas the blinker relay in cars like the E31 and E36 can be switched with low currents. So basically it can be a lot smaller and a lot cheaper. I wanted to do a 4th generation OTTS that would be a plug-and-play replacement for the E31/E32/E34/E36 blinker relay, but I haven't found the time (and motivation) to actual design and build it.

I'm not affraid to solder up the board, but is there anyone in the U.S. that could program the microprocessor for me? I don't want to buy the programmer just for this.

Forum member radlaw might have a spare programmed ATtiny24 microcontroller.

Also, is there any videos of the tripple blink in action? I just want to check out how smooth the operation is.

Smooth? It's just like having someone hold the turn signal lever for exactly 3 blinks in your place. Nothing more, nothing less. It does not affect the blink rate or duty cycle in any way.

[radlaw]

Forum member radlaw might have a spare programmed ATtiny24 microcontroller.

I ended up using another system, http://www.kahtec.com/lane_changer.htm, which was plug & play and simple to install. It has 6 blinks instead of three, which I like. Three just isn't long enough. I started with the OTTS but it was more than I could manage. PM me it you want the materials I have, which include a microcontroller.

[Keith1054]

Thanks for the feedback guys! By "smooth" I was referring to this (there is a video in post #26) that shows a delay between the initial tap of the stalk, and the following blinks.
http://forums.bimmerforums.com/forum...omfort+blinker
Almost looks like the Kahtec takes a second to figure out what to do.

Radlaw, I just sent you a PM about the parts you have

Having a plug and play relay would be awesome, but I understand the developmet time required for something like this.
I have gotten so used to this feature in my Audi daily driver, that I just tap the stalk in the M3 all the time. I think as more guys get this feature in their newer cars and start to take it for granted, more people will be interested in retro-fitting it. Having this system being compatible with pretty much any system is awesome! Revtor, thank you so much for posting all the information on the wiki page, no way I could ever figure this out myself, especially the actual program in C. The fact that you made it availible for everyone is a huge help to the community, cheers!

From a programming standpoint, (which I know nothing about but want to learn), would an Arduino Uno be able to be able to program the ATtiny24-20PU? I mention the Uno since that can do some pretty cool CAN-bus interface functions that I would like to learn more about that as well, and its only like $25

[revtor]

Thanks for the feedback guys! By "smooth" I was referring to this (there is a video in post #26) that shows a delay between the initial tap of the stalk, and the following blinks.
http://forums.bimmerforums.com/forum...omfort+blinker
Almost looks like the Kahtec takes a second to figure out what to do.

Yikes, that looks weird .

Rest assured that neither my OTTS or jalt.de's Komfortblinker module show this behavior. Each blink is and remains controlled by the car's own flasher relay so the blinking rate is not affected. In one-touch mode the Komfortblinker "mimics" holding the turn signal lever for a certain amount of time (adjustable). My OTTS module is slightly different in that it's not time-based but blink-based. It "mimics" holding the turn signal lever for a certain number of blinks (3, 4 or 5 - or any number you want if you change the source code and reprogram the device). That's why my module needs feedback from the flasher relay. The advantage of the latter is that my module also supports "full flash" like in modern cars. The disadvantage is more wiring.

The Kahtec module on the other hand monitors the flasher relay output and if it detects a single blink on the left or right side it will inject 6 more blinks independently from the flasher relay - it's a flasher relay by itself. The reason the module seems to wait after the first blink is because it must be sure no blink is following (to detect a single touch). The delay is probably on the (very) safe side to cover different blinking rates from all kinds of vehicles and the module's own blinking rate may be different from that from the vehicle it is installed in. The module is clever because it supports a wide range of vehicles with very simple wiring regardless of the flasher relay and turn signal switch types, but it's clearly limited by its design.

From a programming standpoint, (which I know nothing about but want to learn), would an Arduino Uno be able to be able to program the ATtiny24-20PU? I mention the Uno since that can do some pretty cool CAN-bus interface functions that I would like to learn more about that as well, and its only like $25

I have no experience with Arduinos but I've read about people using them to program Atmel AVR microcontrollers (which includes the ATtiny series). Please note that you will have to use in-system programming (ISP) but the OTTS module does not have an ISP header on the board. You'll have to program the ATtiny off the the board.

[Keith1054]

Finally got mine wired up on my e36 and it works awesome! Operation is flawlessly smooth, feels like it came installed from the factory. The adjustability in the number of blinks is really cool.
Thank you radlaw for the parts and revtor for your help and all the information. Highly recommended mod!

[clockwork]

radlaw, no issues with this Kahtec product or wiring up? did you have to splice into wires I assume?

I've looked at their products before for the blinking tail lights. nice idea. the ambulances here have them installed on their LED's and they definitely catch your attention when flashing for a few seconds at stops.

[radlaw]

radlaw, no issues with this Kahtec product or wiring up? did you have to splice into wires I assume?

No issues with the Kahtec product. I had an automotive electric shop do the wiring/splicing in the trunk, following the Kahtec directions. I love it.

[clockwork]

Rad law great to hear. May grab a few then. Looks like an extremely simple install. just have to decide where to tap into the signal light wires. LKM or near the tail light housings thesemselves. figure I may do the trunk as it will be easy to hide the black box, and I can use a piggyback fuse in the rear fuse box and run a wire to each turn signal wire at the harness. simple and hidden.

[MParallel]

As E36 M3 owner I have successfully installed one from jalt few years ago and it works perfect.

Same here. Also got a Jalt.de unit (I first got the wrong version for later cars with negative trigger instead of positive (or was it the other way around?) but when I got the correct one, it was an easy fit and works perfectly.

I love it on the highway.