Any Cycle Analyst alternatives?

[Panzer04]

Looking at putting together a torque-controlled ebike, but have been somewhat surprised by the lack of alternatives to the Grin CA. I'm sure it's a nice piece of kit, but it kind of hurts to pay 250$ AUD+ for what is presumably 10$ of embedded hardware and PCB. All I really need is something that takes some inputs and generates a custom throttle signal from that.

Are there any existing alternatives? Worse comes to worse I'll either bite the bullet and buy a CA, or consider engineering one myself.

I've found that this exists:

GitHub - jenkie/Arduino-Pedelec-Controller: Software for the Pedelec/E-Bike controller based on Arduino hardware, see www.pedelecforum.de "ForumsController"

Software for the Pedelec/E-Bike controller based on Arduino hardware, see www.pedelecforum.de "ForumsController" - jenkie/Arduino-Pedelec-Controller

github.com

though I'm slightly put off by a lot of the docs existing in German. Has anyone here tried it out?

Cheers

 

[stancecoke]

Has anyone here tried it out

There is a long thread about the "FC" in the German forum. But the developer of the project wasn't seen since a very long time, so I think the project is dead.

ForumsController

Alles zum Forenprojekt "ForumsController", einem Pre-Controller mit umfangreichen Einstellungsmöglichkeiten.

www.pedelecforum.de

There is a polish alternative also, but almost no reports about it.

MPe computer for e-bike - explore a number of capabilities

The MPe computer is a unique and probably the best solution on the market, for use with all types of e-vehicles. Explore MPe features.

ebikecomputer.com

Why do you want an additional hardware? Anything can be implemented in the firmware of the BLDC controller directly...

regards
stancecoke

 

[Panzer04]

There is a long thread about the "FC" in the German forum. But the developer of the project wasn't seen since a very long time, so I think the project is dead.

ForumsController

Alles zum Forenprojekt "ForumsController", einem Pre-Controller mit umfangreichen Einstellungsmöglichkeiten.

www.pedelecforum.de

There is a polish alternative also, but almost no reports about it.

MPe computer for e-bike - explore a number of capabilities

The MPe computer is a unique and probably the best solution on the market, for use with all types of e-vehicles. Explore MPe features.

ebikecomputer.com

Why do you want an additional hardware? Anything can be implemented in the firmware of the BLDC controller directly...

regards
stancecoke

The main feature would be mapping a torque controller input to a throttle input (since I gather most controllers don't have a native way to support that setup). At that point it'd also be handy to monitor the rest of the system like power/speed etc, but that's really a bit of a secondary requirement since inline ammeter and wheel-based speed measurement are simple enough.

I guess supporting it in the controller would be fine too, but i presumed it would be more difficult than just having something in between to tweak settings with.

I had a quick look at MPe, but unfortunately it appears just as expensive, if not more so than grin :s (and I couldn't actually find a purchase link either). Maybe I'll just have to rig something up with an ESP32 XD

 

[wturber]

Looking at putting together a torque-controlled ebike, but have been somewhat surprised by the lack of alternatives to the Grin CA. I'm sure it's a nice piece of kit, but it kind of hurts to pay 250$ AUD+ for what is presumably 10$ of embedded hardware and PCB. All I really need is something that takes some inputs and generates a custom throttle signal from that.

Are there any existing alternatives? Worse comes to worse I'll either bite the bullet and buy a CA, or consider engineering one myself.

I've found that this exists:

GitHub - jenkie/Arduino-Pedelec-Controller: Software for the Pedelec/E-Bike controller based on Arduino hardware, see www.pedelecforum.de "ForumsController"

Software for the Pedelec/E-Bike controller based on Arduino hardware, see www.pedelecforum.de "ForumsController" - jenkie/Arduino-Pedelec-Controller

github.com

though I'm slightly put off by a lot of the docs existing in German. Has anyone here tried it out?

Cheers

I'll pinch a penny as tight as just about anybody, but to distill the Cycle Analyst down to $10 of embedded hardware is just silly. There is a lot of time and development that make the CA more than just $10 of embedded hardware. That said, I understand if it is overkill or too pricey for your needs.

Do you have the torque sensing BB yet? If not, Grin has a smoking deal on a 127mm square taper torque sensing BB for $60 US. I Installed on on my current cargo bike.

Fischer AG Torque Sensing BB, 127mm

Excellent Deal Bottom Bracket Torque Sensor from Fischer-AG. Senses Left Crank Pedal Force Similar to THUN/NCTE and Requires Drilling Hole in Bottom Bracket for Cable Exit. 127mm Sqare Taper Spindle and 68mm BB Width.

ebikes.ca

I'm no electronics guy, but the torque sensor outputs two speed/cadence signals and a torque signal. Frankly, I'm not sure you need to used the speed signal. I know the CA does. But frankly, I wonder if just using the torque signal might be better. How hard you press the pedal would control how much assist you get. You'd just have to map the torque signal output to the throttle input. Given that the two voltage ranges are about the same, I wonder if you could just connect the torque signal output directly to the throttle input and have a working system. You could tune the sensitivity with a simple potentiometer.

OK, that's me just thinking out loud. I haven't tried this. It may not work. Or it might work, but poorly. It might be a stupid idea. But I guess my main point is that it doesn't seem to be a horribly complex thing. I bet there are any number of electronics projects out there that could be adapted to this functionality.

I recall that there was once a project on this forum that hacked KT controller firmware. You might look for that thread (Kunteng Controller Open Firmware) and see where it is at and what was developed.

 

[Panzer04]

I'll pinch a penny as tight as just about anybody, but to distill the Cycle Analyst down to $10 of embedded hardware is just silly. There is a lot of time and development that make the CA more than just $10 of embedded hardware. That said, I understand if it is overkill or too pricey for your needs.

Do you have the torque sensing BB yet? If not, Grin has a smoking deal on a 127mm square taper torque sensing BB for $60 US. I Installed on on my current cargo bike.

Fischer AG Torque Sensing BB, 127mm

Excellent Deal Bottom Bracket Torque Sensor from Fischer-AG. Senses Left Crank Pedal Force Similar to THUN/NCTE and Requires Drilling Hole in Bottom Bracket for Cable Exit. 127mm Sqare Taper Spindle and 68mm BB Width.

ebikes.ca

I'm no electronics guy, but the torque sensor outputs two speed/cadence signals and a torque signal. Frankly, I'm not sure you need to used the speed signal. I know the CA does. But frankly, I wonder if just using the torque signal might be better. How hard you press the pedal would control how much assist you get. You'd just have to map the torque signal output to the throttle input. Given that the two voltage ranges are about the same, I wonder if you could just connect the torque signal output directly to the throttle input and have a working system. You could tune the sensitivity with a simple potentiometer.

OK, that's me just thinking out loud. I haven't tried this. It may not work. Or it might work, but poorly. It might be a stupid idea. But I guess my main point is that it doesn't seem to be a horribly complex thing. I bet there are any number of electronics projects out there that could be adapted to this functionality.

I recall that there was once a project on this forum that hacked KT controller firmware. You might look for that thread (Kunteng Controller Open Firmware) and see where it is at and what was developed.

Yeah, I'm being a little bit disingenuous. Obviously there's r&d and so on involved with these sorts of parts. This is a small market, so most of the cost is in the design. Still, it's been around for over a decade at this point (and I guess this demonstrates the smallness of the market) with few cheaper alternatives.

I guess it's a bit frustrating because a Chinese motor kit with controller is basically the same cost as the CA alone :'(. Torque sensors aren't cheap, but still cheaper than the CA. I can imagine designing a CA-alike product over the course of a few months (trying to be fair about the breadth of features it offers in addition to other things).

Maybe it'd be a fun project, but it's still a substantial effort if I dont actually make it into a product. I just wish grin priced it a little cheaper so I didn't mind just buying it instead .

 

[wturber]

Yeah, I'm being a little bit disingenuous. Obviously there's r&d and so on involved with these sorts of parts. This is a small market, so most of the cost is in the design. Still, it's been around for over a decade at this point (and I guess this demonstrates the smallness of the market) with few cheaper alternatives.

I guess it's a bit frustrating because a Chinese motor kit with controller is basically the same cost as the CA alone :'(. Torque sensors aren't cheap, but still cheaper than the CA. I can imagine designing a CA-alike product over the course of a few months (trying to be fair about the breadth of features it offers in addition to other things).

Maybe it'd be a fun project, but it's still a substantial effort if I dont actually make it into a product. I just wish grin priced it a little cheaper so I didn't mind just buying it instead .

My first ebike used a $225 motor kit. That included a PAS sensor, LCD display, motor controller, throttle, and complete wheel with hub motor. While the LCD display would show voltage, it didn't show amperage draw or watts. It didn't show accumulated watts drawn or charged. So I ended up spending $50 for some electronics to do that. Actually, I spent $65 because I spent $15 initially for a cheap ammeter that wasn't particularly accurate, reliable or easy to use. So I ended up spending the $50 later.

If you have more time than money, then it makes sense to look for alternatives to the Cycle Analyst. But if you plan on playing with ebikes for the long haul, it might make overall sense to buy one. Now that I've played with one for a while, I kinda wished I had swapped out my original KT LCD display for a CA years ago. That bike was wrecked recently and I may very well do that if/when I resurrect it.

 

[stancecoke]

The main feature would be mapping a torque controller input to a throttle input (since I gather most controllers don't have a native way to support that setup)

Which controller do you use? There are open firmware projects that allow the direct attachment of a torquesensor to the controller for Kunteng and for Lishui.

There is a project with minimal hardware (Digispark, 3.60$) for your purpose also:

GitHub - stancecoke/Minimal_E-Bike_Torquesensor_Precontroller: based on a digispark

based on a digispark. Contribute to stancecoke/Minimal_E-Bike_Torquesensor_Precontroller development by creating an account on GitHub.

github.com

This calculates the riders effort from cadence * torque on the crank and sets a proportional throttle signal.The assist factor can be set by the poti. But of course, this sets the speed, not the motor power, as there is no extra control loop for the battery current.

regards
stancecoke