Thinking of a new gadget...

[peterbaron]

Carry on Csory...or you may pop out Honda logo and place your screen there, if there is sufficient room ..looks like OEM

[SportsterDoc]

To have an ammeter does not necessarily mean having a shunt (heavy gauge wiring and fire hazard). Hall-effect or contactless meters could be used to get a ballpark figure (such as the CSLA1CD). I was considering this before but found it to be "information overload" on a 3-digit display. Maybe a character LCD, but then again, wanted something less intrusive...
Ok, just a quick update: printed in white ABS to check size and shape. On a second thought, I'd probably mount it flush with the metallic bezel (i.e. to be level with the Honda logo). Also, the final version will be printed in black ABS, epoxy-treated and painted matte black to get rid of the printing hairlines.

True, as used on variable speed drives for overcurrent monitoring:

https://www.veris.com/docs/app/vn07_H614...s_RevC.pdf

https://www.veris.com/docs/Datasheets/H614_d0117.pdf

However, in the 1960s and earlier, auto applications were generally shunt.

[Paris_imp]

There are a few instruments I was missing from my previous rides. Battery voltage from my scooter, engine and ambient temperature from the ST1300... I know that the CB is all about "back to the roots" and such, but not stressing the engine until oil warms up a bit seems like a good habit to me. Also, a quick look at the battery voltage would give an early warning to hook it up to the charger. Ambient temperature serves self-mocking: no, it is not that cold at all, don't be a puss*...

Always the tinkerer, decided to build a custom instrument. 3-digit 7-segment red LED, located just above the center dash in a 3D printed plastic housing that blends into the factory molding. Two temperature sensors (oil and air), battery voltage meter and an ambient light sensor to auto-adjust brightness. No buttons. It goes like this:

(a) ignition on, engine stopped: battery voltage
(b) engine running, oil cold: oil temp alternating with "OIL" message to indicate cold engine
© engine warmed up: air temp

So far got to the point of designing electronics, ordering parts, and started tinkering with the 3D model... Sorry about posting a "work in progress" but I am genuinely excited Stay tuned...

What an interesting idea. I'm a big gauge fan. I like the new heads up OBDII displays for cars that are all over Amazon, but motorcycles are not cars. While I would like to know what the oil and engine temps are as I ride along, and the battery voltage too, I am not sure it's a good thing, for me at least. It is very tempting to keep an eye on all that, but I truly cannot devote my full attention to the road if I do. The less I have to distract me, the safer I am on a motorcycle. That's just my preference, but I am honestly impressed with the idea and the skill required to pull it off.

[Csory_imp]

Ok, some progress here... Just received the black ABS filament I'll use to print the housing. Decided to go with black instead of silver - silver would never match the brushed aluminum look of the instrument cluster, black will be the least obtrusive option.

Put together a model to test parts - seems to work okay. The final device will have slightly smaller 7-segment modules, but you can already have a look at how it works below:

[GoldOxide_imp]

That is some nice first-principles work there Csory. Nice to see the minimalist approach. Would you happen to know the average current draw of the prototype accessory?

In addition, the mood music just would not let go my attention.

[Csory_imp]

GoldOxide: current draw is entirely dependent of display light levels. Sensors, PSU and logic requires about 5mA total, display will take another 30mA (maximum) or 2..3mA (minimum)@12V. To keep current draw and heat build-up minimal I'll use a tiny buck regulator (TSR1-2450) instead of the linear 7805 you see here. Power is switched though - no ignition, no amps drawn... Will measure it though once I have the smaller 7-seg modules at hand.

[Ben70_imp]

Is it too late in the process to suggest tire pressure sensor readout?

Ben

[Csory_imp]

Is it too late in the process to suggest tire pressure sensor readout?

Ben

This must be with tongue in cheek... Wait... It is, isn't it? Technically, it's doable, as long as you mean the battery-powered transmitters attached to the rim. Problem is with weight and being battery powered. I'm not a fan of those... You can pry my Bourdon from my cold, dead hands

[GoldOxide_imp]

GoldOxide: current draw is entirely dependent of display light levels. Sensors, PSU and logic requires about 5mA total, display will take another 30mA (maximum) or 2..3mA (minimum)@12V. To keep current draw and heat build-up minimal I'll use a tiny buck regulator (TSR1-2450) instead of the linear 7805 you see here. Power is switched though - no ignition, no amps drawn... Will measure it though once I have the smaller 7-seg modules at hand.

Thanks Csory. I suppose worse case scenario load.

[Csory_imp]

GoldOxide: Display current is now limited at 20mA/segment@5V. Absolute maximum rating for the display itself would be 40mA. Once I have assembled the final version will test for required maximum brightness and adjust current accordingly - then measure what I ended up with. If your question is about connecting this to an unswitched circuit, I'd rather modify operation slightly:

(1) keep measuring battery voltage once per hour, store the result, send electronics into deep sleep mode inbetween, no display at all.
(2) when battery voltage goes above 12.7V (i.e. generator charging = engine runs) display would come up as normal, showing previously measured battery voltage, then go on as usual. This could also be triggered by pushbutton or gyro (i.e. a tap on the display or moving the handlebar a bit).

Typical power requirement would be 1mA for this setup (while the engine is not running). Self-discharge of the CB1100's SLA battery equals to about 0.8mA (11.2Ah, 5% per month).