Grin Base/PhaseRunner without Cycle Analyst

Is it possible to run a pedal assist only configuration utilizing the Sempu BB without the CA? I am wanting a very discreet setup because of theft concerns and given the use of the bike would not have much need for active monitoring after initial setup in the Grin controller software.

If this is not an option with the Grin controllers what would be a good alternative controller to consider?

NoClassic said:

Is it possible to run a pedal assist only configuration utilizing the Sempu BB without the CA?

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Sure. The Phaserunner will take a straight throttle signal without the CA.

Is the output of Sempu BB correct for that controller input?

NoClassic said:

Is the output of Sempu BB correct for that controller input?

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No. On top of the signal voltage range not matching what you would expect from a throttle signal (which you can correct for in the Phaserunner programming software), the Sempu bottom bracket requires a 10v power supply that the Phaserunner doesn't provide, and there's nowhere to plug in the Sempu's cadence sensor, so that'll just be ignored, resulting in an experience that's different than intended even if you do get it working.

Thanks so much for the additional information here and within the ebike subreddit NCC1941.

Are you aware of any other controllers that would allow a more minimal installation while still offering FOC and torque sensor based pedal assist?

Would it be possible to use a PAS display that connects to the throttle input with the phaserunner, like this one from em3ev?
https://em3ev.com/shop/pas-controllerdisplay-sensor/

Are there any Arduino projects people have used for a similar purpose? The CA3 is so big and chunky.

Jatem said:

Would it be possible to use a PAS display that connects to the throttle input with the phaserunner, like this one from em3ev?
https://em3ev.com/shop/pas-controllerdisplay-sensor/

Are there any Arduino projects people have used for a similar purpose? The CA3 is so big and chunky.

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Sadly not, afaik.

I'm searchig for similar solutions.

Maybe some "pre controllers" could work that are designed to give a signal output from ~0V to~5V depending on several input factors incl brakes, throttle, PAS, etc...

What I do own but what i didn't try yet is an mmc-3 precontroller from https://elfkw.at/produkte/controller/mmc-v3-bluetooth

(don't know if an english describtion is available)

I do use one with a 10 year old chinese controller + small geared hub motor to make the system EU legal.

You can define v-max, A-max (from battery) and how the throttle works. Didn't try if regen is possible, too, maybe not in combination with PR which puts the regen not on a brake contact but on the throttle input.

The mmc-3 is not able to get an input from a torque sensor, but only from simple cadence sensors. You have an input if you do pedal, but not how much.

The mmc-3 is quite expensive, too, but you do not need that huge CA3 on your handlebar. A smartphone can do the configuration and can serve as a display, but you can ride it without.

you can set two configurations, i.e. one street legal and one not. Changing modes can be done via smartphone (hidden or not) or at system start.

not ideal, but this is what I do have.

"pre-controllers" is pretty good, is that term standardized?

Are there others?

I think "meta-controller" could be more accurate, given the "control limiting", some offer monitoring, post-ride statistics etc

I would be interested in a 'pre controller' that worked with common torque/cadence sensing bottom brackets and converted it straight to a throttle signal for use with a baserunner/phaserunner without needing a CA. Bonus points if it did regen based on pedalling backwards etc.

Maybe we could pool our resources to fund someone with the skills to do it / do a group buy if a custom board leads to the best result? Anyone else interested? Maybe we could even convince Grin if we get enough people?

It seems like the device you just described is exactly a cycle analyst. Just get one of those.

Yes in order to recover development costs, can't see a "crippled CA" like that being much cheaper.

Plus ones you get all those added features for free, I'm sure some of them will come in handy.

Cephalotus said:

Maybe some "pre controllers" could work that are designed to give a signal output from ~0V to~5V depending on several input factors incl brakes, throttle, PAS, etc...

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Sure, you could build one, if you know how to either design opamp circuits or program MCUs.

Realistically it's a lot easier (and likely cheaper than all the development costs) to just buy a Cycle Analyst v3 and set it up for what you want (although it does not do *everything* the way I personally need it to, it works for most people that use it for this).

I've been thinking for a while about a simple hardware circuit that would take pulses from a common cadence sensor and integrate them into a "constant" voltage output, with a simple adjustment knob for min throttle voltage out, and another for max throttle voltage out, and a simple gain knob to let you set it up for your particular cadence vs throttle output. It shouldn't take more than $10 in parts including a bit of perfboard to wire it on, or perhaps $15 or so if a PCB was made for it in enough quantity to make them cheap.

A bit more complexity would allow a brake cutoff input to shutdown the throttle output.

A bit more complexity from there would allow the use of some torque sensors instead of just cadence.

But this kind of system is so simple it's not really that tunable to a particular usage scenario, unlike the CA, unless you make even more complexity to the circuitry and more adjustment knobs. Very much of this and it gets a bit on the large side, and becomes cheaper and easier (especially for the end user) to do this using an MCU, programmed for the task. At that point, it's easier to just use the CA3, unless it simply doesn't have the feature(s) you need.

The mmc-3 is quite expensive, too, but you do not need that huge CA3 on your handlebar.

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You don't "need" the CA on your handlebar at all.

You can mount it wherever you like, once configured (which can all be done via the USB-serial cable and the Windows or Apple setup program). Stick it in with the battery or the controller, or wherever else you like.

If you don't ever want to see the display on it at all, and don't mind some DIY, you can even take it out of the case and cut the LCD off, and have a smaller board you can package however you like.

If you like you can still even use remote buttons, switch, or knob via the Aux input, where the buttons/switch/knob is mounted whereever you can reach them, to change certain things on the CA "live", like switching presets, or amount of assist, etc.

Does anyone know if it's possible run a Phaserunner without a Cycle Analyst and still have regen braking? Does it accept a basic brake signal?

Thanks

pwd said:

Does anyone know if it's possible run a Phaserunner without a Cycle Analyst and still have regen braking? Does it accept a basic brake signal?

Thanks

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The Phaserunner doesn't accept a basic on/off brake signal, but it does have a second signal wire hidden under the throttle connector's shrinkwrap (normally wired in parallel with the main throttle signal wire), which you can separate. This second signal wire is used for proportional regen, and you can wire it up to a second throttle or throttle-like input to control your regen braking.

For example, you can have a righthand throttle for... throttle while also having a lefthand throttle for regen, or you could use a cable throttle converter like this one to map proportional regen to a typical mechanical brake lever.