Sharing experience with (Russian) Swallowbot

[Tommy Hilfaker]

@trevmar

Oh, not good to hear that....hope you get well soon. 

 

[68bugboy]

Finally got to do the downgrade to 1.1.7

I don't have an android, so I borrowed one from a buddy.

The app worked great!

Just did a 16.75 mile trip.  The 1.1.7 firmware is WAAAAAAAY better than 1.4.0

Pushback is much more mild, especially on up hills.

Thanks MRN76 for a job well done!

[Tommy Hilfaker]

Found something interesting:

https://www.ninebot.run/services/proshivka-ninebot-mini-pro-23-km-ch/

And

 

https://krank.au.ru/11649042

Does Alexey has his own "partners" now?

[mrelwood]

I also finally got an Android device to be used for these purposes. Downgraded MiniPro from 1.4.0 to 1.1.7 with the Ninetool (2.2 something) beta. MiniPro battery was at two bars, but I went on a quick ride. I weigh 92kg. Impressions:

As noticed and described by others, the tiltback behaviour is a lot nicer! I was able to go uphill a good amount faster. I even got up a very short and very steep uphill that I was not able to do with the 1.4.0 even on full battery! Riding up curbs, or over roots on an off-road path also works a lot better, since the MiniPro now tilts back only slowly, which makes it behave normally during short high-power demands. It starts to tilt back, but by the time it is even noticeable, I had already cleared the obstacle.

This will be a great firmware for the winter! On heavy snow the 1.4.0 often tried to stop me before I even got it going forward on level ground.

I’m pretty sure I also got less swaying left-right during high speed turns. With the 1.4.0 I felt that the steering was too sharp even at it’s lowest setting, so that when I started to turn, it would turn a bit too much, so my sideways lean would be cancelled and I would continue straight for a bit during the turn. I think the turn was now more predictable and smoother from start to finish.

I was able to ride at a steady 16km/h at 1/2 bars of battery.

I don’t understand why and how anyone can go so much backwards when developing new firmware. I get that they tried to make it safer. But it wasn’t safer, it was just more intrusive, less capable, and a less stable ride.

[trevmar]

5 hours ago, mrelwood said:

I don’t understand why and how anyone can go so much backwards when developing new firmware. I get that they tried to make it safer. But it wasn’t safer, it was just more intrusive, less capable, and a less stable ride.

When a development team is led by an outstanding programmer, most of the expertise disappears when the product goes to production, and that coder is let-go, or reassigned to a different department. That happens all the time, and as an engineering manager, I see 1.2.7/1.2.8 as a totally incompetent (and failed) attempt to move the project forward with a different team, while 1.3.0 and 1.4.0 represent the output of a team that is just not capable of retaining all of the complexity of miniPRO control in their collective consciousness.

Jojo says he was told that the key coding was done by a brilliant high-school student in his vacation, and everything I have seen fits in with that scenario.

I find that the v1.1.1 firmware that came with the control board from China is even more pleasant to ride than 1.1.7. The pushback does not shift your balance, the platform just beeps a lot and slows your speed without much tiltback when pushing against a difficult hill. I really like that. V1.1.7 or 1.1.9 is my second choice at the moment, whereas (IMHO) the 1.3.1-based Swallowbot is a pain to drive uphill.

However, after extensive testing, I have concluded that the miniPRO cannot handle loads of more than 85Kg with the 240Wh battery, or 95Kg with a 310Wh battery. It loses control down-hill (see detailed reports in another thread here). Since I weigh 90Kg, or so, I have bruises and dislocated shoulder to attest to this limitation (There is no difference between the two miniPRO 240 and two 310 that I have, except the battery which is fitted). When you change the battery, ALWAYS turn the platform upside down and re-initialize the miniPRO.

Edited July 10, 2019 by trevmar

[mrelwood]

13 minutes ago, trevmar said:

However, after extensive testing, I have concluded that the miniPRO cannot handle loads of more than 85Kg with the 240Wh battery, or 95Kg with a 310Wh battery. It loses control down-hill (see detailed reports in another thread here).

I weigh 92kg + clothing, but I have a lot of experience with both low and high powered EUCs, so I’m pretty confident that I know when to ease up acceleration or braking. The short steep incline to our parking lot is one that I often come down with the MiniPro, but I let it accelerate so that I wouldn’t stress the battery, motors and mosfets. If I tried to crawl it down at a steady speed, I’m pretty sure the MiniPro would give in.

 

13 minutes ago, trevmar said:

When you change the battery, ALWAYS turn the platform upside down and re-initialize the miniPRO.

By your recommendation I did that after the firmware downgrade, but I’m not sure I did it corectly. When I had the MiniPro upside down in my lap, I pressed the power button shortly. It started a series of beeps (8 in a row I think), and blinked the lights. As it was not was I was expecting, I powered off and now pressed the power button for a longer time. Now the wheels started spinning slowly in opposite directions, changing direction every few seconds. The left rear light was mostly green with red leds at the ends, and the right rear light was all red. I didn’t check the front lights. Powering it up when upright behaved normally, and the app showed no issues (except for a newer firmware existing), so I geared up and went for a happy and joyful ride.

Did I re-initialize it correctly?

[trevmar]

The slope that gave me the dislocated shoulder is the steepest around here, a road of about 13 degrees. I managed to crawl uphill OK, and then rode around for quite a while at the top, but when I came down I rounded the top of the hill rather faster than I wanted to go down the slope, so I tried to throttle back. At some point the miniPRO realized it could no longer control the speed with a 240 battery and switched off, throwing me forward onto the ground. The miniPRO ended up beside me, depowered, and beeping continuously (no pauses between beeps). I had to switch the miniPRO off before it would power up again. It is possible that going a little faster may have prevented the catastrophe, as you suggest, but my point is that the platform really cannot be trusted if you are near the weight limit. If I encountered a steeper road or embankment I am sure I would get the same problem, even with the 310Wh battery. The platform should not be doing this, IMO, there has to be a better algorithm to follow when the firmware gives up trying to balance...

I am not sure how to read the LEDs after initialization, but your procedure sounds fine. Just make sure you hold the miniPRO firmly and don't let it wobble when it starts to cycle the wheels.

[mrelwood]

Thanks! How long should I let it spin the wheels? I turned it off after a minute or so, as it seemed it isn't going to do anything else.

[trevmar]

I just leave it for about 5 seconds. That seems enough

[Tommy Hilfaker]

Seems that the Original thread at commercial part of the board has been closed. That was it, guys.

 

EDIT:

It's back....dont know for sure what was the problem with this thread......

Edited August 6, 2019 by Tommy Hilfaker

[mrelwood]

The forum masterminds are constantly trying to fight scam, spam and flooding the commercial section with unrelated ads. Drawing the lines has proven difficult, and one of the latest changes made the Swallowbot thread drop to a limbo slightly outside the said lines. After discussing the matter, they thankfully agreed to include MiniPro type vehicles back at the commercial section.

[Tommy Hilfaker]

Ok, thanks for the Info. That was also in my mind that was the reason for deleting this thread.

[FreeRide]

I'm not sure of the logic in recalibrating the MiniPro every time the battery is changed.  I've done probbaly 50 or more battery changes generally these are mid ride, and I've never recalibrated my MiniPro even once.  Even when I took a new MiniPro and did the Chinese control board and battery swap.  I'm not sure how this sensor calibration would be affected by changing the battery.

[trevmar]

And isn't that exactly the problem, @FreeRide, there is no definitive information about this product available at all.

[Vartha]

On 6/16/2019 at 10:12 PM, MRN76 said:

Hello. Rollback to firmware 1.1.7. so all at your own risk.
http://mrn76.ru/NineTool.rar
(bet beta 2.2.0)
For firmware, you need the version to be higher than 1.4.0 (Should work with 1.4.0 1.4.1 1.5.5 1.6.0 1.6.2 1.6.5)
Connect to the device, enter Enter 117 for the text space and press Flash FW

This is fantastic! Just used it to downgrade from 1.6.5 to 1.1.7. While flashing, I got that "Ïnvalid Floating Point Operation" but flashing continued until success.

[Tommy Hilfaker]

4 hours ago, Vartha said:

 I got that "Ïnvalid Floating Point Operation" but flashing continued until success.

That is an known error. You can read about that in his official thread for flashing with this tool

[mtother]

Hi everyone-

I just flashed 1.17 using the tool provide by @MRN76.  The flash worked, but I didn't do the reset (turning it upside down after powering on; seemed made up to me).  Anyway, was climbing up hill and it just stopped in the middle of the climb (battery was down to 1 bar, too)!  Threw me forward and I miraculously didn't get hurt.  Scared to ride the thing again!  I hated 1.4, but I was never thrown off it before.  I know this is an old thread, but does anyone have any thoughts?

Thanks in advance.

-mr

[mrelwood]

6 hours ago, mtother said:

does anyone have any thoughts?

I don’t know if there are sections of voltage management that are reset by the reset process, but if a reset is advised, it’s generally a good idea to follow the guide. It’s not made up, that’s how the reset is done.

 One bar of battery and climbing up a hill does bring up a few other possibilities though. How steep was the incline? What was your speed, your weight, and did you accelerate? How familiar are you with voltage drop on Li-ion batteries? (Sincere question, I don’t know what you know!)

[mtother]

On 7/6/2021 at 9:51 PM, mrelwood said:

I don’t know if there are sections of voltage management that are reset by the reset process, but if a reset is advised, it’s generally a good idea to follow the guide. It’s not made up, that’s how the reset is done.

 One bar of battery and climbing up a hill does bring up a few other possibilities though. How steep was the incline? What was your speed, your weight, and did you accelerate? How familiar are you with voltage drop on Li-ion batteries? (Sincere question, I don’t know what you know!)

Hi @mrelwood-

Thanks for the response! 

My experience is kind of a blur because I was just testing out the firmware and didn't expect any incidents.  But, I believe I was going at least 8 MPH, maybe more, and accelerating up gradual incline.  I'm 180 lbs. 

Don't know very much about voltage drop of Li ion batteries beyond the fact that it drops as the batteries discharge.  I'm a mechanical engineer so I have basic understanding of electricity.

I knew the risk when I flashed the firmware, but didn't appreciate how dangerous the miniPro is, LOL.

[mrelwood]

1 hour ago, mtother said:

Don't know very much about voltage drop of Li ion batteries beyond the fact that it drops as the batteries discharge.  I'm a mechanical engineer so I have basic understanding of electricity.

Ok. In short, as the batteries are burdened, the voltage drops immediately by a whole lot. It recovers mostly within just a few seconds, and sets to it’s resting voltage in a few minutes. The more batteries there are in parallel, the less the voltage drops. For scale, a 1100Wh EUC with 4 parallel battery cells can momentarily drop from 100% to 0% in a single strong acceleration.

The MiniPro has only one or two parallel cell groups.

For the battery meter not to jump around all the time, the battery meters in almost all battery equipped devices average out the voltage for as long as a minute. On a self-balancing vehicle this however hides the important reduction in operation voltage, which can end up being costly if not known.

 If you accelerate uphill with a single bar of battery, the voltage can easily drop below the operational range. How the vehicle handles this can change based on the firmware version. It wouldn’t be much of a surprise if an older firmware didn’t handle the situation as gracefully as you had gotten accustomed to with a newer firmware. After all the old firmware is liked exactly because it doesn’t tilt back as easily during inclines, making it easier to use more power and cause a larger immediate voltage drop.

 Your experience here might well be the exact reason why Ninebot decided to make it more difficult to use a lot of power on the newer firmware.