Please help with CA3 Programming

adcockj · Mar 6, 2021

I’d like to ask for some help in programming my new CA3. I have it basically working, but it is VERY sluggish and low in power (even though it appears that it thinks it’s providing higher power).

Background: I have a basic DIY rear hub bike with a Bafang G020.500W motor (only 400 miles on the motor). It had a generic square wave 18a controller and a DPC18 display. It all worked fine, with plenty of power for the kind of riding I do -- 16 - 18 mph steady-speed riding on roads and paved multi-use trails. However, I didn’t like that I couldn’t program the speeds for the 5 PAS levels, and the throttle would only get me up whatever speed the PAS level supported.

So...I bought a CA3 with throttle and the MFSwitch), a Grinfineon 20a controller, and GRIN’s 24p PAS sensor. The installation went fine. I had already studied the programming manual and had my initial setup saved on the PC. I programmed the CA3 with these settings, but I obviously have something wrong. As I mentioned, it is very sluggish in any PAS level, though they do seem to (barely) work to the speed set for that level. The throttle, however, is REALLY low level, and only seems to work to get me to the speed for that particular PAS level. I never see more than a couple of volts on Throttle Out, even with 4.1 or so volts on Throttle In.

What I want to do: I want to ride at a steady speed at a given PAS level, with the system giving whatever I need to quickly get/keep me there. I want the throttle to override the PAS level assistance, giving me more power up to the maximum speed set (not the PAS level speed).

What I’m seeing: Understanding that I have NO idea about the underlying stuff, it appears to me that the bike seems to think it’s giving me more amps than it is. I can go through the motions with the rear wheel up, and it seems to work. However, it says it’s using around 350 watts to spin the tire in the air at 20 mph (can’t be so). On the street, it says it’s giving 20 amps and 1000+ watts, often showing the "A" as limiting on the diagnostic display, when it can't be anywhere close to that! Even on a very minor incline, the PAS assistance is minimal (as I can feel the power), and the throttle is even worse. When I look at one of the stats pages, it says it’s using around 50 watt-hours per mile (not possible).

Help needed: could someone take a look at the settings in my setup below and tell me what I’ve missed? Or if you have a setup that should work on a basic 48v 500w Bafang ebike (with PAS switch and throttle), could I get a copy of it? If I could get any setup working, I could probably go from there.

A few notes: 1) I do have a basic understanding of the principles, and have programmed my Trek BBSHD bike to do the above. So I think I’m doing the mechanics of this right, but missing something in the interaction of settings. 2) I entered 30AH for my battery, because I routinely run dual batteries in case I go out for a 30-mile ride and end up going 40+ and then the wind kicks up. 3) I’m pretty sure the numbers are right for the PAS sensor (GRIN’s) and the motor speed magnet number - I have the Bafang motor specs and I counted the arrows on a wheel rotation. 4) When I first loaded a setup into the bike, it was VERY surge - surge - surge on both PAS and throttle. That’s why the Amps and Power Feedback gains are set to 10, which pretty much stopped the surging.

Thanx much!

amberwolf · Mar 6, 2021

adcockj said:
I bought a CA3 with throttle and the MFSwitch), a Grinfineon 20a controller, and GRIN’s 24p PAS sensor.

The first thing I would do is to remove all the power and current limits from the CA. Your controller will do that on it's own, since the current limit of it is the same as that you've set in the CA. The watt limit of 1100 isn't needed either, as that's basicaly the same as that you get out of the controller for your battery voltage. Set the CA to 99999 or however many 9's will fit in the watt and amp limits.

If you set watt and amp limits within the CA, you can have interactions between settings that affect the ramp-up of power, which you may be able to tune out, but since you don't actually need these limits, it's much simpler to turn them off.

Next, make sure you don't have any of the OEM limits set (these are usually "collapsed" settings at the very bottom of the setup program, and don't appear on teh CA itself).

Without these limits, the feedback gains shouldn't matter, but if problems continue, set them back to the defaults (power 150 and amps 15)

The throttle, however, is REALLY low level, and only seems to work to get me to the speed for that particular PAS level. I never see more than a couple of volts on Throttle Out, even with 4.1 or so volts on Throttle In.

Just to test it, set the throttle ramping (not the PAS ramping) to 99v/sec for both up and down. This effectively removes the ramping, so all throttle output directly tracks the input. If this fixes the throttle issue, then we can change things to work on the PAS if necessary.

What I want to do: I want to ride at a steady speed at a given PAS level, with the system giving whatever I need to quickly get/keep me there. I want the throttle to override the PAS level assistance, giving me more power up to the maximum speed set (not the PAS level speed).

I'm not sure if you have the settings the way you want htem for this. (I'm actually not sure that you can set separate PAS and throttle speed limits, if that is one of your goals.) Throttle does always override PAS, even if throttle is *lower* than PAS (so if you were cranking hard but holding throttle down at minimum, you'll only get that minimum output--let go of throttle and it'll go to whatever the PAS is then outputting).

The setup menu explanations for speed limits (quoted below) indicate that the settings you've got are going to limit you to a maximum of 20mph, with the SLim->Max Speed = 20, and the SLim->MxNoPdlSpd = 28 means the throttle will apply power without pedalling up to 28mph (but since you cannot reach 28mph because of the max speed limit of 20mph, it's irrelevant).

This last setting is mostly used so you can limit throttle operation to below some speed, without pedalling...but above that speed, you have to pedal, too, or it won't go beyond that limit. I would set this to 999 (whatever the max it lets you), if you don't intend to require pedalling for the throttle to operate.

[ SLim->Max Speed ]*
Upper speed limit. The CA rolls back throttle output voltage whenever speed exceeds this setting.
OEM->AbsMaxSpeed determines the maximum value for this setting.

[ SLim->Strt Speed ]*
The minimum starting speed that must be reached before the CA will allow power application. This is useful for RC drives or systems with sensorless controllers that do not work well from a dead start. The rider must pedal the bike up to StrtSpeed before power is applied.

[ SLim->MxNoPdlSpd ]*
The maximum speed at which the throttle will apply power without pedaling in any PAS mode. This feature supports European pedalec legislation which requires pedaling the bike for motor power, but which provides exemption below a certain speed (e.g. 6kph) in which case use of a throttle without pedaling is permitted. Applies only if a PAS device is installed.

I can go through the motions with the rear wheel up, and it seems to work. However, it says it’s using around 350 watts to spin the tire in the air at 20 mph (can’t be so). On the street, it says it’s giving 20 amps and 1000+ watts, often showing the "A" as limiting on the diagnostic display, when it can't be anywhere close to that! Even on a very minor incline, the PAS assistance is minimal (as I can feel the power), and the throttle is even worse. When I look at one of the stats pages, it says it’s using around 50 watt-hours per mile (not possible).

That indicates the shunt setting is not correct. The typical Grinfineon shunt value is 1milliohm, if you are using a standalone (SA) shunt. If you are using the controller's shunt, you would need to input the number etched on the face of the controller. If you already have, then try halving that number, or doubleing it, to see how it affects the behavior. (note that if you eliminate the amp and watt limits first, there won't be any limiting behaviors, but you will still see changes in the current and watt readouts).

If the shunt setting already matches the shunt actual value, there could be a bad connection between the shunt wires and the shunt, typically at the "CA connector". On yours, that's probably a Higo rather than the older JST, so they don't have the same kind of common problems JSTs do, but it might still not be fully seated.

After you've tried the above, let us know the complete results, and we can work out any fine tuning that's needed.

adcockj · Mar 6, 2021

Super. Thanx much, amberwolf. I'll start on this, from the top, tomorrow morning and report on my results.

HrKlev · Mar 6, 2021

Everything amberwolf said, but also observe what happens on the diagnostic screen (one tap on the left button from main screen). I the lower left corner, watch the letters. Capital = active limiter.

I would also remove all the speed limiters. High gain settings can make the speed limiter kick in way before the speed limiter.

adcockj · Mar 7, 2021

amberwolf, you are a GENIUS! My ebike went from a beached walrus to a scalded dog!

I made all of the changes you suggested, as shown in the graphic below (BTW, I apologize for the huge graphics in my first posting...I fixed that). Anywhere you see a big number that is NOT 999999999, it's because the programming app changed my input to that number (e.g., the power limit of 50000W vice 99999W).

I didn't know that the throttle-only max was bound by the SLim max...on my BBSHD, it can be higher. No problem with that, though.

I was surprised by the RShunt value. I assumed (yes, I know...) that the default OEM setting from GRIN would have been the proper value for the controller they sent me. But, as you suggested, I looked at the controller itself and fixed that.

So......... now I'd like to go from a scalded dog to a normal ride. Could I impose on you one more time to suggest some normal settings? (I'm about 195 pounds and the bike, with the panniers and extra battery, is about 80 pounds).

Once again, thank you SO MUCH!

amberwolf · Mar 7, 2021

adcockj said:
(BTW, I apologize for the huge graphics in my first posting...I fixed that).

You might want a *little* bigger, it's a bit hard to read some of the stuff in the pic in this post.

I didn't know that the throttle-only max was bound by the SLim max...on my BBSHD, it can be higher. No problem with that, though.

It's something that has been asked about in the big CA3 "beta" thread, don't recall when or by who, but so far never shown up in the capabilities AFAIK.

There is, however, a way to accomplish it, but not direclty within the CA. I"m (very slowly) working on some "TidBits" using Arduino Nano to work around various CA functions / limitations / behaviors, to make it do some of the things I really need it to do differently. All they really do is take in various inputs just like the CA does, check for match with "activation requirements", and then modify the throttle / etc into the CA or out of the CA based on those, but when conditions don't meet those ARs, they just let the CA do it's thing unmolested.

I don't have TidBit notion to do this yet, but if you would really like this capability, it can be added to the list:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=110497
In this case the CA's SLim max would be whatever max you actually want (or none), and the TidBit would need to monitor the actual throttle and the PAS cadence sensor and the speed, and then detect whenever you are *not* using the throttle, and then limit the speed by modifying the input to the CA (or the output from it).

So......... now I'd like to go from a scalded dog to a normal ride. Could I impose on you one more time to suggest some normal settings? (I'm about 195 pounds and the bike, with the panniers and extra battery, is about 80 pounds).

First, you'll need to define "scalded dog", and "normal ride". What specifically is now different from the way you wish it to behave?

adcockj · Mar 7, 2021

amberwolf: I just mean a little softer ramp-up/etc. Tomorrow, I think I'll take a look back at the original settings (other than the max limits and RShunt values) and add them back in slowly and test them. I'm sure I can come up with settings that will work for me, and learn some in the process. Thanx again. I appreciate your time.

amberwolf · Mar 7, 2021

adcockj said:
amberwolf: I just mean a little softer ramp-up/etc. Tomorrow, I think I'll take a look back at the original settings (other than the max limits and RShunt values) and add them back in slowly and test them. I'm sure I can come up with settings that will work for me, and learn some in the process. Thanx again. I appreciate your time.

Ah, softer ramp up is easy. Just change the Throttle Ramp Up to 5v/sec, which gives you about 1/2 second from zero to full throttle (there is usually around 2.5-3v difference between actual minimum and maximum throttle voltages). If you want faster ramp up, just increase that number proportionally to how fast you need it to be.

Personally I prefer no ramping, and just learn (quickly) to handle the throttle precisely, to get the acceleration I wanted. After a few rides on each version of each setup it became second nature (most of my stuff is in the 4kw+ range, but are heavy-cargo bikes/trikes, so that's like a 2kw or less setup on a regular bike).

Having a ramp up means you can never use "emergency" GTFOOTW

power/speed in traffic if someone else does something stupid that you cannot avoid by braking or slowing, but can only avoid by going faster momentarily. Might not happen where you ride, but it does here. :oops:

With no ramp other than my muscle control

I can instantly have full power if i need it (rare, but it does happen).

adcockj · Mar 8, 2021

The bike is running great. I went on a 30-mile ride today, trying a few different settings along the way.

My #1 observation: that using throttle limit rather than speed limit in the Digital Aux Settings made the bike perform much more smoothly. When I had it set on Speed Limit, it was a little awkward...a lot of off-on-off, sometimes seeming to take a few seconds to decide that it was going to react, and the throttle would only take me up to the speed AT THAT PAS level, not the max speed I had set. When I changed to Throttle Limit, the power was much smoother in application throughout the band, and assistance at and around the "cruising" speed for each level was very consistent. Also, the throttle worked up to the top of the max speed I had set, rather than some reduced number based on the PAS level.

I'm extremely pleased with these GRIN products and how they work on this bike...it's now a smoother, more enjoyable ride than my Trek with the BBSHD. And I very much appreciate the help I got on this forum. Thanx amberwolf.

Beansong · Jan 26, 2024

Thanks for this conversation. It's valuable information for readers considering buying a CA kit.

Please help with CA3 Programming

adcockj

10 mW

amberwolf

Administrator

adcockj

10 mW

HrKlev

1 kW

adcockj

10 mW

amberwolf

Administrator

adcockj

10 mW

amberwolf

Administrator

adcockj

10 mW

Beansong

1 µW

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