[runesm]

Straight from jlcpcb, is crankshaft then ready for vr or hall? What mods to swap sensor type on crank? And same for cam, what sensortype, and what mods to swap sensor type?

With a soldered MAX9926 the Inputs are optimized for VR Input. But normally these Inputs should also work for Hall signals.
Depending on the input voltage from your Hall sensor you should connect VR- to Ground at 5V input signals and on 12V signals it would be a good point to start with VR- connected to +5V.
Depending on the used sensor it could be also necessary to put a pullup resistor (4k7 or 10k) to 5V or 12 V

If you have HALL on both signals (CAM/CRANK), you can also dismiss the whole MAX9926 (putting pullups on both signal inputs if not provided in the sensor) . But be careful as the maximum permitted input voltage is 5V....

Hi Cris!
I had some problems with the VR input, with an inductive sensor, which generated many peaks of non-existent signals. Even without connecting the sensor, when starting the engine, it detected signals. Reviewing the generic connection schematic of the max9926, I was able to notice that it is also recommended that it contain a Bias, which I added after the two previous resistances to the max, and it worked perfectly. , it may be necessary to include the pads to optionally add the resistance, in order to eliminate the noise that generates false triggers, since when it started, it also caused the rpm at start to shoot up to 10,000, it was a real pain to Head on, I hope I can help someone else who has the same thing happen to them.
excellent job guys!
Greetings!

Can you explain where you connected the resistors?

[NickZ]

normally you connect 4.7k resistor across the VR sensor wires.

[Hich]

Hi,
It seems I can’t blame the error with the oxygen sensor on Ali but on my poor soldering skills:( that seems to work now ok.

What I am stuck with now is the ignition. The CDI unit in the old system seems to expect a different trigger. See

Old system
IMG_1853.jpeg (2.8 MiB) Viewed 2631 times

Here the spark is triggered when the signal goes high and the level is around 1V only.
Is there an easy way to modify the IGN output to handle such unit. Or what would be an appropriate driver module to use. I read something on a Bosch 124 module, which sounds a bit like overkill (we are talking about a 200cc scooter).
Thanks a lot Karsten

The pictures are switched:(

[chaoschris]

...and the level is around 1V only.
Is there an easy way to modify the IGN output to handle such unit. Or what would be an appropriate driver module to use. I read something on a Bosch 124 module, which sounds a bit like overkill (we are talking about a 200cc scooter).

Unfortunately the minimum allowed supply voltage for the 4424 is 4,5 Volts and up.
Are you sure the input of your CDI can only handle 1 Volt? I have no experience with such units, but this looks also strange to me.
Wouldn't it be an easy fix to change your ignition coil to a model with integrated driver? There are a lot of models around which are also really small and cheap. I have something in mind like these from the older american V8 engines (LS2/LS3) which are easy available, small and cheap

[Hich]

Hi Chris, thanks for the feedback.
Honestly, I have no clue what this specific CDI can digest I have tried with the inverted signal and it looks more like a firework of sparks:) perhaps it is already broken. I was thinking that some other production scooter ignition system should work, however, some of them have rpm limitations, and/or advance curves and it seems hard to find a good documentation (https://www.scooter-center.com/en/cdi-b ... ed-bgm6669)
The LS2/LS3 could be defnitely an option, I assume this would work: https://www.motordoctor.de/products/8344519-zundspule?
I have meanwhile ordered a Bosch 124 clone and will first try that...

[JHolland]

Here the spark is triggered when the signal goes high and the level is around 1V only.

Are you measuring with everything connected together? If this is a signal into an ignitor/CDI box then it may be that you are driving into the base of a transistor, in which case you would need to measure the signal disconnected.

[PSIG]

Reviewing the generic connection schematic of the max9926, I was able to notice that it is also recommended that it contain a Bias, which I added after the two previous resistances to the max, and it worked perfectly

To side-step a moment; what mode did you configure for? Did you also pull-up ZERO_EN, or … ? Sometimes it helps to remove some of the "smart" in the MAX chips, but not sure what you did.

[runesm]

Reviewing the generic connection schematic of the max9926, I was able to notice that it is also recommended that it contain a Bias, which I added after the two previous resistances to the max, and it worked perfectly

To side-step a moment; what mode did you configure for? Did you also pull-up ZERO_EN, or … ? Sometimes it helps to remove some of the "smart" in the MAX chips, but not sure what you did.

Hey mate, quoting the wrong guy, i quoted another

[PSIG]

Oops, yeah - right quote, wrong guy.

Reviewing the generic connection schematic of the max9926, I was able to notice that it is also recommended that it contain a Bias, which I added after the two previous resistances to the max, and it worked perfectly

To side-step a moment; what mode did you configure for? Did you also pull-up ZERO_EN, or … ? Sometimes it helps to remove some of the "smart" in the MAX chips, but not sure what you did.

[hoopstar]

Is the BlitzBox available for purchase from anywhere (ideally in Australia) or is it purely send it to a fab house to have made?

Problem with the latter is typically MOQ is five (5) units.

Apart from that, this unit is absolutely perfect for motorcycle upgrades.

Cheers

Hoops