Thinking of a new gadget...

[Csory_imp]

Max: This uni-mount idea is great. However, it is outside of my mechanical skills and capabilities - can't see how I could print it and make it tough enough to resist vibration... There should be some short of a tensioner mechanism to make it stay at the selected angle... The rotary can't be permanently installed on the wiring since it is non-waterproof - the 6-pin socket, on the other hand, could be.

My initial reservation re: one universal unit was that it would be ungainly thick to look nice on the center mount. Now working on a visual prototype for that - will be about 3.5mm (0.14") taller than the standalone display... If people would more like to have a single unit I might change plans and go with that...

 

[GoldOxide_imp]

Was a bit surprised :huh: to learn that most of you (who sent me a PM showing interest in the final device) would prefer to have it pre-attached to the angled mount. This brings me to the following idea: will check if I could cram the electronics of the center module into the angled mount itself. That would make it a "single module" device. Will be back with the result soon. This will not require re-designing electronics (it is already as small as it could be), just a new angled mount to be printed if dimensions seem to be ok.

If you consider this optimization, then please consider not permanently affixing the Display Module (DM) to the Central Module (CM). This will allow the option to affixing the DM at "normal" or upsidedown on the angled mount so it can be placed elsewhere, instead of on a hydraulic reservoir.

That said, maybe consider a second choice (or an additional BOM item) "non-angled" mount (basically a rectangular matchbox) to affix the DM. The advantage of this is the electrical connection between the DM and CM won't have to be concerned about orientation to each other.

In short, across various riders and machines, the flexibility for mount should be maintained for universal application and wider deployment acceptance.

Not sure that I get this "matchbox" thingy right: the DM is already a flat square box. You mean to add another one underneath to make it sit higher?

(The "all-in-one" would be non-separable, since there would be no connecting cable between the CM and DM. If someone would like to alternate between mounting options, that means separate CM and DM.)

Not sure that I get this "matchbox" thingy right: the DM is already a flat square box. You mean to add another one underneath to make it sit higher?

(The "all-in-one" would be non-separable, since there would be no connecting cable between the CM and DM. If someone would like to alternate between mounting options, that means separate CM and DM.)
Yes, the "matchbox" would be essentially the CM.

By integrating only the angled piece basically reverts the premise of a common CM for all current and future configurations and untold products (but really, this is your baby to determine). The angled piece also limits end user orientation choice. I may use the angled bracket in some application, but not others. It depends on what and where it will be ultimately mounted.

If you choose not to have the current CM integrated with the DM, but only have the angled bracket as the housing of the CM, then the only other recommendation I wish to share is have the option in the DM to digitally invert the display 180 degrees.

Does this make sense?

The 180 degree display rotation is already implemented (see "Setup" section in the Manual).

Putting the CM and DM in the same housing (adding the "matchbox" beneath) would make the entire unit about 8mm taller - contrary to my original design goal of being as flat as possible for center mounting. The connecting cable between the CM and DM is cut-to-size and can not be changed later (at least, not without some soldering), so there is no true "universal" mounting option for every possible scenario. Maybe if I move the step-down converter from the electronics panel that would make it a bit flatter... will check.

A question to all the others who showed interest: would you rather go with the current version, or prefer a slightly taller "all-in-one", where the central module and display module are in the same housing?

Ah ya, 180 degrees - sorry I missed that (Page 17 in V1.04 of BikeGadget document).

An integrated (thicker) set-up would be desirable, but not be necessarily locked down in a wedge mount. However, since the display digitally supports inversion, that could be a moot point. A scaled sketch could clarify the fashion.

 

[Csory_imp]

Created an all-in-one mock-up. Parts are in, but still waiting for the new circuit board (this version ended up being a complete redesign to shave off as much height as possible). It is now a single module (everything is built behind the display). Horizontally is about 3mm=1/8" less than the previous one. Height was increased by 3.5mm=5/32" - this is where all the original "central module" electronics are crammed in now. See the image below to visualize the difference: new (all-in-one) is to the left. Please let me know if you prefer this "all in one" over the previous two-module design. Will also send a PM to those who were interested...

 

[Csory_imp]

Finished protoyping the all-in-one version. The main problem was eliminating the original power supply and building a much smaller one to make the unit as flat as possible. Switched from 3x2 to 6x1 pin header for the rotary and programming connector for the same reason.

There are a few more tweaks to be done - the ambient air sensor placement is a bit off, and still waiting for a special ultra-low-profile inductor from Japan (that will shave off another 0.75mm if it works). Will keep using the flat ribbon cable for the first 5 inches since that is easier to conceal.

Those of you who were interested opted for the all-in-one, so I abandoned the two-module design.

 

[Lord Popgun]

I have to say, you do nice work Csory

 

[peterbaron]

Marvel

 

[Bazbro_imp]

Spot on, Csory. Lovely job.

 

[GoldOxide_imp]

I think Csory just likes to 3D print whenever he can.

 

[TwoBrothersBusa_imp]

Looking good sir!

 

[Csory_imp]

Time for an update hy: It's been quite a while since the last one - and I've been busy with tweaking the final design.

First thing first: the new inductors are in, work flawlessly, and the new power supply design ended in significantly lower power consumption. Now it is 5.3mA with backlight off, and 7.3mA with backlight fully on (both measured at the 12V input).

The smaller inductor allowed a smaller Schottky-diode (0.5A instead of 1A), making the 6-pin socket connector the tallest component on the board. This made me put on my thinking cap: if only I could put the connector side-by-side instead of on the board... ended up redesigning the entire PCB, flipping it upside down and creating a "notch" for the connector (on the left side):



Also, reduced board thickness from 0.8mm to 0.6mm. These two changes shaved off 0.8mm thickness of the display module, as you can see on these newly printed housings:



While still waiting for the new boards to arrive (due in this Thursday), worked a bit on the software too. Main changes are:

- Option to use icons instead of text for "oil" and "coolant" temperature, see image below. The black "drop" represents engine oil, while the horizontal lines were meant for coolant (reminds me of a radiator grille):



- Advanced setup now skips steps that are non-relevant in the given configuration (i.e. coolant sensor adjustments will not show up if there is no sensor attached).

- Connection error with sensors will show "N/C" message instead of garbage temperature values:



- This is a hardware change, but has software implications: with the more efficient power supply I could double the system clock. This also doubled the frequency of backlight switching - now looks even smoother when dimmed.

Also, five set of cables are ready. The one with the rotary button is for adjustments, the other one is for programming. Opted for 90-degree connectors on the BikeGadget's end, allowing better access when the display is already mounted on the bike (see below).



Once the new boards are in I'll go ahead with manufacturing and - finally - sending the units out

 

[Bazbro_imp]

Wow! What a great progress path you've followed, Csory.

This is going to be one great item.

Looking forward to getting mine.

 

[GoldOxide_imp]

Slick! I really like the summary dashboard - everything at a glance. Well done on the optimizations.

 

[TwoBrothersBusa_imp]

The new changes look fantastic. Can't wait to see the "new" finished product!

 

[Csory_imp]

New boards are in one day earlier. Could not resist - put together the first one (no display yet, only electronics.) So far, so good.



Here you can see how I could save some thickness by putting the connector "into" the notch



Housings will have to be re-printed since the opening for the ambient temperature sensor is a tiny bit larger than it should be.

 

[TwoBrothersBusa_imp]

This is just an amazing project to watch unfold. Thank you so much for sharing.

 

[GoldOxide_imp]

Really of thing of art, Csory.

 

[Cormanus]

This is just an amazing project to watch unfold. Thank you so much for sharing.

Well said, TwoBrothers.

 

[Bazbro_imp]

Hear hear, TwoBrothers.

 

[Csory_imp]

Today's update

Mated the first of the new electronics with the display. Later on, it will be a no-brainer, but proceeded with caution with the new design. First, powered up without the display and checked the power supply circuit:



It was 3.294V at 12V input, well within limits for the nominal 3.3V. Next, soldered on the backlight and LCD modules - as you can see here, not much space left in between:



Yaay! Everything went smoothly - display lit up, and the programmer was able to "talk" to the unit. Right now it is just a small (and useless) paperweight - first will have to be initialized and calibrated. There is a special program for that, used only during this step of manufacturing. So loaded this calibration routine, and started with initializing the default values:



Next comes the issue with timekeeping. To save weight and size, the BikeGadget uses an internal oscillator built into the processor. This oscillator provides an 8MHz clock frequency, but it is a much less precise source than external quartz crystals. One method to improve precision is calibration. There is a divider built into the chip, and by adjusting the value of this divider the frequency can be tuned. The program emits an 500Hz signal (or what it believes is 500Hz), then the divider is adjusted one step at a time until the emitted signal's frequency gets as close to 500Hz as it can be. Here I could adjust it to 499.984Hz which is pretty close Originally, it was 473Hz - that would have made the ride timer about 5% late.


Now that we have the unit initialized and the clock source calibrated, time to calibrate the voltage measurement circuits. The same logic applies to all three inputs (battery voltage and the two temperature sensor inputs). There is a separate "magic number" for each input used as a multiplier which can be adjusted using the rotary button. By measuring the actual input voltage and adjusting this magic number until the BikeGadget displays the same (or very close) voltage we can have the inputs calibrated permanently. This multiplier is then stored in the EEPROM (non-volatile memory) of the unit, and can not be changed afterwards. (There is a slight variation between components from unit to unit, hence the need for individual calibration. But since these components are soldered in, there is no need or way to change their values - therefore, no need to ever change this ratio...)

In this example, the input voltage was 12.1567V:



By adjusting the coefficient to 16.081, the BikeGadget measured 12.157V - as close as it gets... Note: in normal operation these voltages are displayed using 1-decimal precision, but internally are represented with the full 10-bit resolution.



Next step will be soldering the main cable and casting the electronics into epoxy (using the printed housing as a mould). More about these in the next update

 

[Cormanus]

Brilliant.