Between R-Net CJSM2 and LED Joysticks

[SweetBearCub]

Given that the CJSM2 cannot be made to display an accurate speed or mileage with motor encoder addons, what is the advantage in having the CJSM2 over the simpler LED joystick with a mode button and other bits?

I will want the joystick to control lighting, and I'm not sure if the LED joystick can do that.

Eventually, I'd like to add something like an Android tablet that can be made to read data from wheel sensors to display a more accurate speedometer and odometer, along with a clock, alarms, and notifications. Since I live in a very dense city, GPS would not be operable all the time, or it would be inaccurate, whereas a wheel sensor would be more accurate.

[Burgerman]

Both joysticks are similar. If you dont care about a bright clear screen you can see outdoors which i very useful when using all the seating options via joystick and a few extra buttons and options and IR and possible BT then theres little difference.

Can I ask what the advantage of super accurate mph is?

[SweetBearCub]

Can I ask what the advantage of super accurate mph is?

Because I want it, and knowing that it displays fake data to me irks me. It should just not display that information if it has no way to count it accurately.

My current chair only has a single seating option (tilt), though I want my next to have elevate as well. My tilt is currently run through a very small momentary switch that hides under an armrest, and works when the chair is off or if I'm driving and need to tilt up to clear a curb cut.

I much prefer that method of operation, and will specify it for elevate as well.

[Burgerman]

A typical car spedometer is anywhere from 5 to 10 or more % fast. And typically underdamped or overdamped. So that you can stop hard and then watch the needle slowly drop to zero. Or watch it overshoot as you accelerate and decelerate. That doesent seem to worry anyone.

A power chair is so slow that an innacuracy seems prtty much irrelivant as you just go as fast as what feels right just as you do when walking or running. Why would you even need a speedometer for this? But then everyone is different. Its really accurate enough and can be calibrated by you to suit if you wish. As long as you are not too concerned with reading speed while turning or curb climbing etc. Even GPS isnt accurate in small distance use. Esp if you dont go in straight lines. But for average distance over time its very accurate.

As for switches, thats what the typical switch setup does through the R-Net system. Such as the programable ctrl-5 ones I have on the Q700R that I am looking at. It allows many more isnstant options and mixes, inhibits, speed changes etc too. All programable. Yes much more expensive that a simple switch but also more options too.

[SweetBearCub]

Cars have small inaccuracies, and I don't expect anything to be perfect. But I object to being fed completely false data that bears no relation to reality. Hell, at least the power meter bears some relation to reality, as a voltmeter averaged over time, that also tries to take cable resistance/length into account.

If I am going to have a speedometer and an odometer, then I want them to be as accurate as reasonably possible or they are useless to me.

As far as the common Ctrl+5 box, I want the functions like that, but I want it through two fingertip sized buttons that are hidden under my non-joystick armrest, as my chair does now for one function. Less crowded looking, sleeker.

[Burgerman]

Easiest way to get reasonably accurate speed/distance is a simple bycicle speedometer.

[11ydy]

The premise of accurate speedometer is correct programming, the value of Maximum Rated Speed ​​is set to the maximum speed of the wheelchair，The fastest speed of my wheelchair is 12MPH

QQ图片20230204094729.png (19.42 KiB) Viewed 722 times

This is my travel record. The total mileage displayed on the Joysticks has increased from 3837km to 3853km, which is consistent with the mileage recorded by the GPS software.

[Burgerman]

Neither GPS or the wheelchair can give accurate results. GPS is very close but for e.g it cannot communicate indoor or in some big cities because of the buildings. S if it loses you for a while you may do 10 laps of the multi story car park it doesent know about. And your chair is just guestimating the distance based on speed and time. But it doesent actually know your speed. I can make it read as if I am moving while I push the stick sideways to turn against the curb for e.g. So not moving at all but the distance is increasing...

So you you can be lucky and it may be close for a while. But it might not be close next month.

[11ydy]

Neither GPS or the wheelchair can give accurate results. GPS is very close but for e.g it cannot communicate indoor or in some big cities because of the buildings. S if it loses you for a while you may do 10 laps of the multi story car park it doesent know about. And your chair is just guestimating the distance based on speed and time. But it doesent actually know your speed. I can make it read as if I am moving while I push the stick sideways to turn against the curb for e.g. So not moving at all but the distance is increasing...

So you you can be lucky and it may be close for a while. But it might not be close next month.

I live in the countryside and have been using GPS software to record travel mileage. It is very accurate. The newly replaced PJSM can display the mileage. Compared with GPS software, the error is not large. I think this is usable. Of course, I will continue to test its accuracy.

The PJSM bought on ebay is cheap, and the screen is too dark outdoors as you said

[snaker]

@11ydy: 12mph is very impressive for a sock chair. I am curious what chair are you using? Is there any link to it?

[Burgerman]

You mean its one of those permobil cheap copy ones?

The joystick doesent matter here. Its all in the power modules programming. So if you put it up against a curb and it stalls, the power module doeset know you are not moving. It just sees the increased motor voltage (pulsewidth actualy, caused by the load compensation) and presumes you are moving. It doesent have any RPM or other motion sensors. So it adds distance while you stay still. It also adds more distance than it should on a steep hill. And less on the way down. And along a cambered road it over reads as it wastes power trying to go straight. But these errors on a typical day average out if your trips are consistent. But the errors arrise when say you spend a day at a grass airfeild. High current = over reading distance as you move about in small trips, turn in place a lot etc. GPS in these circumstances do the opposite. You can waste a lot of power going nowhere turning in place watching planes, esp on grass. And the small trips a few yards here and there dont fully get picked up as it averages distance covered over time. So the further you travel in straight lines the more accurate GPS gets. So a lot of S turns and it under reads...

[Burgerman]

Darker smaller screen, 2 buttons missing is the permobil copy one. But it wont affect the "miles" readings. For those that dont know the difference.

Permobil use both of these. On the left the R-net CJSM2. On the right the Permobil PJSM. Both MAY work on normal R-net systems. But they do have non standard R-net firmware. So no garantees there wont be some kind of issues..

[11ydy]

@11ydy: 12mph is very impressive for a sock chair. I am curious what chair are you using? Is there any link to it?

Hello, the original speed of my wheelchair is 10KM, 3.00-10 drive wheels, I replaced the 21:1 gearbox, the motor speed is 4300, lithium iron phosphate 10S, RNET output voltage is set to 32V, the root speed is 19KM, the previous 9S +VR2 output voltage setting 25V speed is 16KM

[11ydy]

Darker smaller screen, 2 buttons missing is the permobil copy one. But it wont affect the "miles" readings. For those that dont know the difference.

Permobil use both of these.

The picture is cheap and I bought a small screen, which is not ideal for outdoor use. I didn’t find a cheap CJSM2. Is the brightness of Permobil’s large screen CJSM2 normal? If I have a chance, I should replace it with a large screen.

[Burgerman]

Yes, permobil dont make the larger screen one.
Its a geniune R-Net (Penny and Giles/Curtis Wright) one. The only thing permobil do to that is use their version of the firmware.