The IC inside the CDI

[Louis]

Hello Olivier,

Sorry fore the somewhat late replay, had visitors.

Its all difficult to say. Because without no HV input, ignition and pv's wont work.
I could only tell witch where the pv by switching on/off the cdi and let it do his cleaning cycle.
There I noticed those pins swishing (around 5V)

Pin 22 : From the pickup circuitry, Is the signal 0-5V pulse / square form wave ?

Could not measure this on the 00cdi. But done this on the 3MA-10 cdi
With these results (a small notice the 3ma-10 cdi has hardy any 5V more like 2,5V?)


This signal change a bid when you turn at the TPS sensor (so output signal i think)


This signal is a steady signal (no changes with the tps sensor) it only changes when the rpm rises

I guess this will be about the same on the 3ma-00cdi perhaps (more around 5V ore less)

Pin 36 37 33 : Does the signal variation is continuous  (maybe not application for the Speed sensor)

Yes, You see the value go up or down by turning at the TPS, same with the pv up and down (cleaning cycle)
Speed sensor is 2,2V to 5V when you block the optics (2,2 open 5v something between optick)

Pin 13 : Does the signal have only 2 states : 0V or 5V for driving ignition coil ?

Can't tell exactly but think yes 0V ore 5V the frequency is the rpm

The clock frequency is written on the part : 6.000MHz or so...

It has written 600NDK91

[Louis]

Ok it looks like the parts are affordable. That's a good thing

If We design a IC/PIC Why not use only the signals that we need.

-Side swish and speed limiter (don't need them)
-Airjets could be handy in a later version. (for now don't need them)

Only
-TPS (signal)
-PV's (pos signal)
-PV's control signal
-Pickup signal
-Ignition signal
-Working voltage
-Mass

That should be around 8 wires

On the new pic board it self we can make the communication.

Or isn't it that simple
This is also a nice site: http://www.transmic.net/en/16628-v7.htm

By the way, Can't I bypass the HV circuit so I can test the rest off the signals properly

Think somewhere on that circuit board, the HV signal should be brought down to usable voltage.
Any ideas on this

[Fotis]

Louis the toshiba t2333 must be the bridge for the servo. Yamaha uses the same on the ypvs controllers if i remember correctly...check its outputs to see if they go to the servo

[Louis]

Hello Fotis,

This treat is flying with all that good info

There are two T2333 on the CDI board, non is connected to the pv directly. (what I can see quickly)
Can measure one with the pickup pulses.

But......

There is a third one also a Toshiba but differently (can reed the number as its all waxed in)
belief something with a 8 in it.



Goes directly to the pin 5 and 6 (marked in red and the red dots)
So that will be the one 'bridge for the servo''

We are going great, another component known now

[tzr-v4]

If We design a IC/PIC Why not use only the signals that we need.

-Side swish and speed limiter (don't need them)
-Airjets could be handy in a later version. (for now don't need them)

Only
-TPS (signal)
-PV's (pos signal)
-PV's control signal
-Pickup signal
-Ignition signal
-Working voltage
-Mass

That should be around 8 wires

On the new pic board it self we can make the communication.

Or isn't it that simple
This is also a nice site: http://www.transmic.net/en/16628-v7.htm

On the PIC, we can easily get the 11 signals:

-TPS (signal)            => Analog input 0->5v
-PV's (pos signal)    => Analog input 0->5v
-PV's control signal => 2 digital outputs 0v or 5v states
-Pickup signal         => 1 digital input 0v or 5v states
-Ignition signal       => 1 digital output 0v or 5v states
-Working voltage   => 5V or 12v (depends if the PIC board had a voltage regulator on)
-Mass                     => Must be the same as the YAMAHA CDI board for signal
-Airjets                   => 2 digital outputs 0v or 5v states
-Side swish and speed limiter (don't need them)

Will try to setup a PIC schematics.

We need to look, for the PIC choice, at the internal resources we need :
- 2 analog inputs
- 5 digital outputs
- 1 digital input
- 1 timer to count pickup signal period or frequency (RPM)
- 1 timer to count the delay time between pickup signal and Ignition signal (according to CDI curve)

We could easily add a communication with a computer using serial port with a cable, USB adapter or bluetooth adapter.

I've already made a programmable YPVS box but was struggling with capturing ignition signal (0v -> -200v) on the orange wire of the loom.
http://ypvsbox.free.fr/?page_id=88

[Louis]

Think I got him.

Its the MB88P505H (build in 1987)

http://pdf.datasheetarchive.com/datasheetsmain/Datasheets-112/DSAP0049312.pdf

Pointing out some interesting facts



Pin 1 and 2 (Not connected, possible programming function)

Pin 13 pickup input signal???

Pin 16 and 17 where giving a sinus signal
Why?. because they are directly connected to the external Cristal (clock)
(the red dots)

Pin 18 Is directly connected at the T2333 (green dot)

Pin 19 and 20 Are not connected (They don't need to external function)

Pin 22 rpm signal (Perhaps its the outgoing signal, (because pin 13 is only a input port)

Pin 23 and 24 Are connected to each other, but if I read it correctly that is possible

Pin 25 Has a function as test terminal. Giving the measured signal

Pin 41 Start signal

Etc etc.
For the ones who know what they are doing (not me)
Please reed the datasheet, and tell me if I'm close

If I have more time will try to measure those signals Exact

But if this is the correct IC, is it programmable?

[stevewr250]

Hi boys i'm loveing this thread it's a pitty i haven't got a f$"£&^G clue what your all talking about
I should have paid attention at school
only joking i do get the general idea keep the good work up
Steve

[tzr-v4]

Louis,
I've downloaded the datasheet and I'll study it tomorrow afternoon.
In the morning I'll be lecturing PIC Micro-controller for the engineering students.

I'll post back.

[Louis]

Hello Olivier,

Quick note, Just read that the

-MB88P505H is a (one time prom) ''OTPROM'' is this one only programmable one time?

The

-MB88505 - MB88505H have a mask ROM (programmable)
http://pdf.datasheetarchive.com/datasheetsmain/Datasheets-28/DSA-544172.pdf

Family/series off the

-MB88500H
-MB88501H
-MB88503H
-MB88505H

Like to know if we have a one time programmable or a normal? Programmable.

The pin setting is about the same with the MB88500 onwards serie.
So hopefully we have a programmable

[4l04ever]

It is unlikely to be a programmable device.  More likely to be a mask rom device - this means it is preprogrammed when it is made and cannot be changed later.  This would be the case to stop any corruption rather than to stop it being updated.

[tzr-v4]

I'll check this evening at home but I think we should not try to find more details on the IC.

We should do some live testing to get the correct wave form of the signal :
- Test the YPVS during cleaning cycle :
    - closing : pin XX at 5V and pin YY at 0V
    - opening : pin XX at 0V and pin YY at 5V
    - YPVS sensor pin :
         - fully opened = XX Volt
         - fully closed = XX Volt
- Test the TPS
    - TP Sensor pin :
         - fully opened = XX Volt
         - fully closed = XX Volt

To do so you should solder on the board an IC socket to plug the original IC and check the signal while the bike is running.

With this information we could setup a PIC to emulate the original IC.

Sample 1 : drive the YPVS motor using the TPS
   - when the TPS is closed then the YPVS is closed
   - when the TPS is opened then the YPVS is fully opened
   - otherwise in between

[Louis]

Hello guys,

Steve, we will certainly keep up the good work
Looks like we have a good change that in the end a replacement IC/board is made.

It is unlikely to be a programmable device.  More likely to be a mask rom device - this means it is preprogrammed when it is made and cannot be changed later

''That'' Will most likely be the case, I'm just pointing out some possibilities to make sure we high light all options.

For example:

If the IC is only programmable one time then ''OK'' but will it be possible to read it's program off?
If this is possible, you can change that program to what ever you need and program it back on a new IC
As it looks like these IC's are still for sale
http://www.galco.com/buy/Fujitsu/MB88P505H

You see, just Like to know what IC is used, in order to understand it better

For me the goal is
-To find witch IC is mounted.
-Will it be possible to replace it by something modern

A topic with two question's

[Louis]

Hello Olivier,

I'll check this evening at home but I think we should not try to find more details on the IC.

A little bid focus on the Old Ic wont harm us Just like to know what IC we have exactly and what we can do with it. (programming/reading)

Dont worry, will focus on the signals

We should do some live testing to get the correct wave form of the signal

Will give it a go.
Remember I work with two 3MA00 CDI's
-one with IC removed
-one completely stock

So measuring signals is still possible

Have ordered a IC socked/strip for the First test project CDI

Hopefully my motor speed controller will be here within a couple off days.
Than it should be possible to (simulate a working engine)
And can I measure the signals more exact

[tzr-v4]

That's fine.

I'll do 2 test's samples :
-1) Capture RPM simulation signal and compute retard delay and then CDI Advance
-2) Capture TPS position and drive YPVS servo to have YPVS Position sensor (voltage) equals TPS position (voltage)

I'll try to list the electronic bits you'll need for this to test.

The PIC will send the data to the PC using serial port and data will be stored in a file for post visualization.

[Louis]

- Test the YPVS during cleaning cycle :
    - closing : pin XX at 5V and pin YY at 0V
    - opening : pin XX at 0V and pin YY at 5V
    - YPVS sensor pin :
         - fully opened = XX Volt
         - fully closed = XX Volt
- Test the TPS
    - TP Sensor pin :
         - fully opened = XX Volt
         - fully closed = XX Volt

It sounds easy measuring the cleaning cycle

But the whole cycle takes about 1 a 1,5 sec. My multimeter is not that fast
So my values on the display are jumping

Best will be if my ignition tester is ready so can give it (relative) steady pulse
So measuring will be more exact.

Think these measuring will give you a idea.


The IC seems to have a steady/starting point (always the values come back to those values)

Sample 1 : drive the YPVS motor using the TPS
   - when the TPS is closed then the YPVS is closed
   - when the TPS is opened then the YPVS is fully opened
   - otherwise in between

Would it not be logical to position the ypvs compared with the rpm?