Home Built Gear Position Indicator (GPI)

[scoutdriver73]

Hi all,
I did some searching and didn't find any home made solutions on the forums so I thought I would share this.

The original idea and plans that this thread is based on come from pdfruth, a poster on st-owners.com. The hardware/software design is all his. His original post/thread can be found here.

Brief overview:
1. Install a home made GPI monitor four signals from the bike.
2. The GPI uses a PIC (programmable integrated circuit) to run the software needed to interpret signals
3. The GPI controls an LED display, which indicates the current gear
4. The GPI requires four signals from the bike:

Ignition Pulse Generator - IGP
Vehicle Speeds Sensors - VSS
Neutral Indicator/switch
Clutch Indicator/switch

Brief instructions:
1. Order/find necessary parts (pdfruth does sell kits with all the necessary parts if needed. See this post his first post.)
2. Assemble GPI
3. Program the PIC with the supplied code (kits from pdfruth come with the PIC already programmed)
4. Install GPI and LED on bike.

I installed one of these on my st1300 and on my VFR. The instructions are for the ST, since I did that first, and then there is some additional information for specific to my 2000 VFR.

This is what I did to build the hardware for the ST
1. You can get the PIC for free. Go to http://sample.microchip.com/Default....stCookies=true to request samples. You can get up to three 16f88s. Microchip will ship them to you for free.

2. I didn't have a programmer, so I built one for less than $5 with parts from Radio Shack. I built the simple JDM version found here. The page has info for helping you testing the programmer to make sure it works right before plugging in your chip. It took me about 30 minutes to build the programmer on a breadboard. (There are lots of schematics for PIC programmers on the internet, but not all of them will work with the 16f88.)

Please note that JDM style programers require a "real" serial port on the PC. Many "newer" PC do not supply enough power to the serial port if it even has one.

3. I used IC-PROG which can be found here to control the programmer. The site with the JDM programmer instructions also has instructions for setting the options in IC-PROG.

4. You have to compile the source code which jdfruth provided. Download all parts of the source code and combine into one file (I've included a single file). Give the file a *.asm extension. Download MPLAB IDE from microchip which can be found here. Install the software and find the file MPAsmWin.exe (do a search in your install directory.) This program will compile your *.asm file into a *.hex file.

5. Use IC-PROG to burn hex file into PIC

6. Follow directions/schematic supplied by jdfruth to build you circuit and enjoy.

VFR Specific:
The hardware is the same as for the ST. The clutch and neutral signals can be found at the clutch diode, just like the ST (the wire colors are even the same). The diode is in the fuse panel just in front of the battery. The IPG and VSS signals can be found on the Grey plug for the ICM, which is on the back of the bike. All you need to take off to access these points is the seat.
The IPG is the yellow wire and the VSS is "one" of the two pink wires. See pictures for more info.

The program for the PIC had to be modified slightly to get it to work with the VFR. The VSS signal has a much lower frequency than on the ST. Below is the single change to the code. Find the code block in the original and replace with below.

Due to the low frequency of the VSS, the indicator will not be accurate when going less than ~ 10mph. I did design a signal multiplier which would fix this, but never built it and now I don't know where I put the plans.

;This routine tallies up counter shaft rotation cycles emitted by the VSS.
; Each time this ISR is driven, the counter shaft will have rotated a fraction of a full revolution.
; Note: On the Honda RC51, there are 27 pulses per counter shaft revolution.
; Here we effectively divide the VSS frequency by 128.
; We use a RAM variable (VSSINT) as a boolean indicator of these rotations.
; Every 64 cycles from the VSS will result in the VSSINT variable switching from 0x00 to 0xFF
; or vise versa. The state of the VSSINT variable is monitored in the main loop routine below.
incf VSSINTS,F ; Increment the VSSINTS ram variable

;*********************************************************************************************
; Changed freq divider from 128 (6) to 32 (4) due to the decreased number
; of pulses on the VFR - Edited 03/22/08 by Joe Wagnell
btfss VSSINTS,4 ; Have we tallied up 8 (0x08, B'00001000') of em yet?
;**********************************************************************************************
goto IntSvcExit ; No
clrf VSSINTS ; Yes, so restart the counter
comf VSSINT,F ; And toggle the VSSINT flag

Please note:
I installed this on a 2000 VFR. Other years may have variations which will require modification of the instructions. Also, Gen 4 and earlier may not have the require sensors/signals to hookup the GPI as described (IPG ???).

The source code that I've included already has the changes noted above. 2002 and later bikes might have a different speeds sensor which would require this value to be changed again.

I have included the HEX file that I used on my VFR project. The included pictures show the locations of all necessary connections on a 2000 VFR.

I had to remove all the pictures from the instructions so that the file would be small enough to post. The original instructions can be found on the st-owners forum.

[Wesley J]

Tres Cool

Wesley J

[Witch Doctor]

Wow! I had read the article about the RC51 gear shift indicator, and the author mentioned "someone" had modified the code for a VFR. Nice work!

I'm fixin' to get into PICs and this would be a good, as well as functional starter project. Thanks for the tip on the programmer; I thought I was going to have to buy one of the pre-made PIC programmers out there.

Each time I read about this project, I start thinking about using "vampire taps" to hook it up to the bike's electrical system, instead of messy soldering. Thing is, the last time I remember hearing about vampire taps was on old co-ax network cables.

[scoutdriver73]

Originally Posted by Witch Doctor

Each time I read about this project, I start thinking about using "vampire taps" to hook it up to the bike's electrical system, instead of messy soldering. Thing is, the last time I remember hearing about vampire taps was on old co-ax network cables.

I would recommend that you solder all your connections because of the vibration from the bike. If you need any help, shoot me a line and let me know.

Joe

[MarkBartels]

I tried to understand that....it made my head hurt!