Electronics for motorbikes

Programable ignitor

This device I have made for my motorbike after motor modification (increase of power from 20 to 33 kW). The original Yamaha ignitors of this kind are very rare. The device is populated with ATINY 2313 and programmed via ISP port. The power stage uses high voltage Darlingtons. The old version had insufficient cooling of transistors, too high impedance on the MCU's inputs and therefore EMC problems and the software had some bugs. It had IGBTs in the power stage, but after bad experience with other ignitors (see below) I have replaced them with Darlingtons.

old version

old version

current version

current version

The next version (February 2006) of the programable ignitor has a RS232 interface. It was a wish of the friends, who have no ATMEL evaluation equipment. The hardware has been except of adding the RS232 only a little modified. The inputs are so arranged, that not only the inductive pickup can be used, but also the Hall generator, optical sensor or even points. The program written in Borland Delphi calculates the igtition table from given piece-wise linear curve, displays the calculated characteristics and downloads the table into the MCU. It enables also service access into the MCU's Flash. One of the next version will also have an ignition software update function. The Flash of the MCU is devided into the service section (some kind of bootloader), ignition program and ignition table. Last two can be modified using the RS232.

Ignitor with RS232

PCB top

PCB bottom

Wiring

Points controlled electronic ignitor

This device has been designed for my friends who have older XS machines (XS 250, XS 360, XS 400 2A2). Of course, it can be used for any two cylinder motorbike with points ignition. The end stage was first populated with IGBTs, but they suffered from gate breakdowns and they had to be replaced with Darlingtons. The input current (the currenth through points) had to be increased from about 5 mA to 50 mA to avoid instabilities.

Version 1

Version 2

The next version has implemented a timer which switchs the ignition coil current off after apx. 200 ms if the points remain closed for longer time. So the coils are protected againts overheating. Opening of points resets the timer.

Version 3

Version 3 - view inside

Version 4

Version 4 - view inside

Board computer

This is a test version of my board computer, in operation since November 2005. The core is ATMEGA16, the display is 4 x 20 character, HD 44780 compatible. The device has the following functions:

- Immediate, average and maximal speed
- RPM
- Total and trip distance
- Clock and stopwatch
- Gear indicator
- Ambient and oil temperature
- Battery voltmeter
- Tank level indicator

After upgrade in 2006:

- High RMP warning flash (Gear up!)
- Adaptive LED brightness
- Heating of the LCD if the temperature is below 10°C


As the wheel sensor an Honeywell inductive proximity switch and four tinned steel sheets glued around the clincher of the front wheel are used. The tank level sensor consist of 5 reed contacts and a serie of small diodes. The floater of copper sheet carries the magnets. The higher petrol level, the more diodes in serie and the higher output voltage. So only one wire against the chassis is needed. The wire feedthrough replaces one screw of the petrol hahn, so no drilling is necessary. As the gear sensor the modified original neutral switch is used. Six additional contacts and a chain of small signal diodes have been added.

Old board computer

New board computer

Wheel sensor

Tank sensor

Tank sensor on petrol hahn

Gear sensor - inner side

Gear sensor - outer side

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