On 2017-07-31 17:52, John B. wrote:
On Mon, 31 Jul 2017 09:44:48 -0700, Joerg
wrote:

On 2017-07-30 14:27, Graham wrote:

"Joerg" wrote in message
...
On 2017-07-30 02:21, Graham wrote:

"Joerg" wrote in message
...
On 2017-07-29 13:46, Graham wrote:

"Joerg" wrote in message
...
On 2017-07-29 12:16, wrote:
On Saturday, July 29, 2017 at 7:06:59 AM UTC-7, Joerg
wrote:
On 2017-07-29 02:14, Graham wrote:

"Joerg" wrote in
message ...
Had to change the battery again on my Bell
Dashboard 100 cycling speedometer. Or what they
call "cycle computer" In the manual it says one can
re-enter the odometer reading but nowhere it says
how. When I contacted Bell years ago they said "no,
you can't". Does anyone know a secret trick Bell
doesn't know?

I keep a log but it gets old having to calculate
to see when the rear tire or other stuff is
nearing end-of-life. Mainly to avoid a *KAPOW*
surprise way out in the boonies. Many tires don't
have TWI.

-- Regards, Joerg

http://www.analogconsultants.com/

Looking at your day job from the above link why not
just design a circuit to replicate the job of the
magnet which is only a switch which is creating a
pulsed current/voltage read by the head unit
electronics. Then set the tyre size to maximum and
determine the maximum response frequency of the head
unit circuitry and simulate pulses at that frequency.
If the frequency is reasonably high it should not
take too long to reset the mileage. With a tyre
circumference of 9999mm, if it will take that, then
you are looking at 10m per Hz.


Sure I could design a meter that works better than
commercial one. However, I've got enough electronics
projects as it is. When I am fully retired, maybe. But
then I want to ride instead of build replacements for
messed-up commercial designs. On the bikes I already
had to do that for lighting but there it was a
necessity.

If I ever build my own it will be like what cars have
since over 100 years. A speedometer that is backlit at
night, works off the central battery and most of all
never forgets its odometer info.

I think that he was suggesting that you pulse the meter
until it reaches the mileage you originally had.


Yes, I misunderstood Graham. If almost all brands contain
Reed switches like Andrew said that might not be so great
for the lifetime of that switch. Also, it would eat up
battery because there will be a limit in the speed and I
guess that's not the same at on a Ferrari Testarossa. So
I'd have to let that artificial wheel run a long time in
order to get the usual 4000+ miles back in, and next time
8000+, then 12000+ and so on. Most likely that takes
weeks.

-- Regards, Joerg

http://www.analogconsultants.com/

It looks like you still have not got it. Lets forget the
grinder idea as I agree with Andrew about the read switches
and that does tend to rule that idea out. My first idea was
to do it electronically with a simple circuit that would send
relatively high frequency pulses to the appropriate terminals
on the head unit to simulate the action of the switch. From
your decription of your background surely this is a trivial
exercise and I am sure you will have the required circuit
components lying around on your bench. See my earlier posts
as to how long it would take at different frquency pulsing if
you set the tyre circumference to 9999mm. 4000 miles would
take around 180 hours at 1Hz, 18 hours at 10Hz etc and my
guess is that the head unit circuit should at least cope with
that. Any higher frequecy response would be a bonus.


Yeah, I could hack the cable aoart, roach on a MOSFET, wrap
the whole enchilade with duct take and feed pulses from a
function generator :-)
[snip]

Why so dramatic do you just like cludging things with duct tape.
Your head unit has two contacts on the back and my guess is that
if you apply a rapid series of shorts across those two contacts
the unit will display speed. How you might choose to apply those
shorts is up to you: electronically, mechanically eg make a
simple rotary switch driven by an electric drill or even a DPDT
relay wired to self oscillate. The possibilities are almost
endless, relatively simple and do not involve cable hacks and
duct tape cludges


I could probably do that but I am sure they have a lowpass filter
in there to mitigate noise and Reed bounce. Or I could pipe out the
power supply to some metal spots such as a couple of the mounting
screws and supply 1.5V while changing the battery. That way it
won't forget the mileage.

OK I give in. I am largely just a lurker in this group and only chip
in when things look like they are, as one might say, "tech". If you
are the "elecy techy" you claim to be then you could have solved this
problem without even troubling this news group. The reply above shows
that you know how to solve this problem so why waste bandwith?


sigh

Again, the reason for my question is this simple:

1. The manual says you can re-enter the mileage number (without tricks
such as clocking in the equivalent of thousands of miles which slurps
away a lot of juice from the newly installed battery).

2. The customer service says that it cannot be re-entered.

These statements clearly contradict each other. I simply wanted to know
which statement is correct and whether someone else had managed to
re-enter the odometer number, and most of all how.

I can't comment on Bell meters but on other makes, including a very
cheap Chinese meter, if the manual told you that you COULD re-enter
the mileage then it also told you HOW to re-enter the mileage.

What is it that I keep hearing repeated? RTFM?


Read and show us whe

https://www.scribd.com/document/3191...ard-100-Manual

--
Regards, Joerg

http://www.analogconsultants.com/