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About trevmar

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  • Birthday 11/14/1948

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  1. "Dump Editor Ninebot v2.0.0.0 " has all the firmware embedded in it. You just select the version you want (I suggest to try 1.1.9) and MRN76's program did the rest. As I reported in the "only for the brave" thread the precise instructions I followed were those at MRN76.ru, specifically: http://mrn76.ru/index.php/programming which links in turn to: https://yadi.sk/d/HDT0E2UX3G8XYc https://yadi.sk/d/C38vGNAI3LMqKq
  2. Alex, I have been using the 90/65-6.5 off-road 'chunky' tyres as shown when I clicked that link. Grip is excellent, and the tyres 'climb' small potholes and small tree roots well. On roads there is a resonance-speed where the vibration due to the tyre tread gets really bad. You can change the on-road performance by pumping the tyres to 30psi or more, but then they don't spread the load as well at obstacles (kerbs) or off-road. I use 15psi as a compromise, but if I were just off-road on dirt I drop it to around 6psi for the best grip. Even at 6psi the tyre is not deforming the typical 15% of its profile that would indicate perfect grip, they are a really solid tyre weighing about 39ozs.. Unfortunately I can't find any 4-ply-rating off-road tyre which is better than these at the nominal 240lbs maximum weight of rider+minipro. Use slime in lower pressure tyres...
  3. In the settings menu of your app, under "sensor controls" you can set the "ride sensitivity" sometimes called "suspension". I find this helps to reduce the twitchyness of the latest versions of firmware (v1.4.0,1.4.1). Lower it to 20, or so. Same for steering sensitivity. But I haven't tried the newest (Go-kart?) version (1.4.9).
  4. If I remember correctly Eagle (or MRN76) told me that the 1.4.9 firmware doesn't self balance. MRN76's Dump Editor Ninebot allows generation of Minipro 1.4.9 firmware, but the selection is in RED ink. I would not use this until we know more about it...
  5. I was upgraded to 1.4.1, and that version worked about as badly as 1.4.0. The upgrade seemed OK to me. What list are you looking at which stops at 1.4.0? ps: You can tell I am a firm believer inthe old firmware, (1.1.7 and 1.1.9) which many members here still use, and IMO gives the safest rides. Others have reported that iPhone problem, though I am using Android, and I saw no difference in connectivity from 1.4.0 to 1.4.1.
  6. Quick update on MiniPro 2018 cutting out and throwing... I put an old 2016 vintage 5700maH battery running the latest BMS on my 2018 Minipro N3M260 (firmware v1.1.9) and it now goes nicely up and down the end of our driveway, where I used to be thrown almost every time. This is a quick update only, as I now want to examine all the variables - tyres, etc - and thoroughly investigate the peak power which each of the old and new battery packs delivers. I have started a new topic to discuss the batteries. If anybody has both 4300maH batteries and old 5700maH batteries, have you noticed any difference in how each handles minor (1-3cm) obstacles?
  7. I have the More4Mini standard charger, AFAIK. Yes, it is marked as putting out 126W only. 220W is what my AC Wattmeter measures as the power it is pumping into the battery throughout most of the charge. Obviously its charge current drops gradually as the battery gets towards the 100% mark :) (I have allowed for 20W estimated heat loss in the charger circuitry, the meter actually measures 240W)
  8. Interesting, Jojo33! I have fixed my typo (I wrote 28650 instead of 18650). With 18650 LG cells the important thing is not the "11865" on the battery, but the letters MG or MF just in front of that number. Looking at the Chinese battery pack at 3:24 into the Chinese video you linked, the color of the cells can be seen through gaps in the black plastic, and as I suspected, it is the pinkish color of the MG1 cells (see MG1 and MF1 images below). It is 2850mah per cell, so two in parallel in the MiniPro battery correctly gives 5700maH, the rated capacity of the N3M320. Similarly, the use of the cheaper MF1 would give 4300maH, the rated capacity of the N3M260. The 'Charge Doctor' looks interesting, but I achieve the same result by using a true-watt meter to plug the power pack into. I have a '63V More4mini' charging brick which pumps 220 Watts into the battery most of the charge cycle. It must be putting out about 4 amps! This certainly charges the battery as quickly as possible, but for extended battery life I stay with the standard Ninebot 59.5V charger, which only pumps out 120 Watts of charging power, except when I am expecting a long excursion and need the 15% extra miles range from using the More4mini 63V charger. As a hardware/firmware designer myself, I would expect the BMS firmware not to be used to limit the maximum output current of the battery pack. There are some MOSFETs installed on the circuit board in the battery which could protect the battery more quickly with hardware detection, rather than using the ADC in the BMS. But maybe I am wrong, and that is why I am building a special pulse testing circuit which will help me identify the exact peak current at which each battery pack shuts down. This should never happen in normal riding, as the motor controller on the main control board should be in control of the power at all times. But I suspect there is a design fault on the circuit board of the 'newer' batteries in the N3M260. At least, that is my suspicion right now... Thanks for the links you sent, they were very useful...
  9. I have been using MRN76's JTAG firmware upgrade utility on a MiniPro260 to try the many firmware versions. The v1.1.9 is more gentle than the v1.1.7 in push-back, but does otherwise seem the same. I chose v1.1.9 installed as it reportedly has some 'bug fixes' over the v1.1.7. Indeed, I guess I would call a more gentle push-back a 'bug fix' as the v1.17 sudden push-back is very alarming when going up a steep hill.
  10. Excellent info, JoJo! The model being sold as "MiniPro 2018" by Amazon, and others, has the designation "N3M260." My interest is not so much in 'scam' as whether any safety short-cuts were taken when it was released. I took the 310Watt battery pack (5700maH) off the refurb (which is N3M320 production date week 23 of 2016) and put it onto the chassis which has knobbly off-road 90/65 tyres on it and firmware 1.1.9 (N3M260, week 33 of 2017). It works fine, and the correct 5700maH is registered by the firmware (according to the app). My guess is that the N3M320 model's 5700maH battery is made from LG MG1 28650 18650 cells, while the 4300maH battery probably has LG MF1 cells in it. The biggest question in my mind is whether the motor-drive hardware was changed to reduce the maximum current being drawn from the lower-cost MF1 battery-cells, and if so, I suspect that explains why some MiniPro owners have problems with small obstacles, and some don't. I noted that the current sensing resistors in the NM260 were 0.04 ohms, which seems a strange value to use for a battery whose cells are capable of 20 amps continuous discharge (less an arbitrary 'safety factor'). I had been assuming that the current level would be sensed by an ADC in the CPU, but it is always possible that the 0.8 volts is intended to trigger a junction transistor for hardware protection... I need to take out the control board of the N3M320 and see whether its sensing resistors are the same value, and then build a test dummy load which will pulse high currents out of each battery, to find out where the battery hardware cuts out. I am hoping the battery will auto reset after overload, as long as I don't blow the fuse from too much average current. I am aiming for a 1:16 pulse duty cycle and about 0.5 second discharge pulse length.
  11. Nobody seems to know for sure yet. Your report of no problems is comforting If your MiniPro has the battery labelled as 5700maH it is my theory (and hope) that your refurbished MiniPro is close to what the original designer(s) intended, yes :) The 2018 edition units which throw me repeatedly have batteries labelled "4300maH" and came from Amazon seller "Segway USA". I will be doing some more testing on this issue, look for info on the battery situation in the thread I made on the 4300maH and 5700maH battery options :)
  12. I keep getting thrown forward by my US 2018 MiniPro versions. Haven't walked for the last 2 weeks because of a badly sprained ankle apparently caused by a small loose rock on a dressed-dirt path. Sigh So I now have real incentive to figure out what new Segway safety paranoia has led to this unsafe behavior (cutoff at small obstacles). I saw the videos on the MiniPlus negotiating steps, etc, and noted that their battery is considerably larger than the US 2018 MiniPro (Plus is more than 6000maH), so I went looking for a MiniPro battery larger than the 4300maH fitted to the US-2018 models. I just bought another MiniPro from Frys Electronics for $329 (on special this week only). It is Certified Refurbished, and out of the box the battery is 3 bars, and it is working great. But the reason I bought it was for its 5700maH battery. Yes, the refurb battery is 33% larger than the 2018 US MiniPro! Unbelievable... My US models are running 1.1.9 firmware (I JTAGgged the downgrade) and the new Refurb is still running 1.4.0 out-of-the-box The hypothesis I am working on is that the Battery electronics is cutting off the motor power at a lower level than the firmware expects. There is a little on-board storage capacity to keep the main CPU going for a second or two after the battery cutout is triggered. I suspect I am getting thrown because I am 200lb, at the limit of the device capability. Incidentally, the refurb MiniPro is only rated at 85Kg maximum Has anybody already tested the maximum (cutoff) current of these different batteries? I am going to make up a small pulse-discharger to check it out, and see if the peak output current from the US-2018 model has been reduced to match its reduced battery capacity, thus reducing peak motor torque. I expect it has... Grrrr....
  13. Viks, do you know for sure that a later version has this fixed? Personally I am starting to think the problem is indeed the BMS current limit, as 'Floridian' has documented on previous page. Is 1.3.1 safe, is 1.4.1 safe? Thanks for your help...
  14. On my android phone you just wipe your finger down a vacant part of the screen to change the camera back and forth.
  15. The motor is turning at a specific RPM, and the MiniPro calculates your speed by multiplying that RPM with the wheel diameter (and a scaling constant). When you change to a bigger wheel diameter (by using a bigger tyre) you don't tell the MiniPro, so it thinks you are driving about 15% slower than you really are