SW900 wiring, need help Please?

[extreme999]

I've purchased an assembled DIY ebike with a 1500W rear motor and a 48V battery pack.

I have an unspecific inverter/controller which does not have any plugs/flying leads for the SW900. However I did note some solder/lead bits on the pcb marked RX, TX and what I think was 5V (I'll have to get my magnifier out to double check), there's currently no leads/cables soldered in to the identified solder points.

The SW900 has one SM-5Y socket with Red, Yellow, Blue, Green, and black (linked to the second 2 pin SM-2 socket).
The second SM-2Y socket has White and a Black linked to the first socket
According to the blurb enclosed with the SW900, the colours and their task is as follows;
White - DD
Black - Ground
Green - RX
Blue - TX
Yellow - DS
Red - D+

Am I on a loser before I even start?

Thanks in advance for any help you can give

 

[E-HP]

Am I on a loser before I even start?

Thanks in advance for any help you can give

Likely yes. What controller does your bike have (a pic of the label might help)? Displays are manufacturer specific for the most part. You can find info on them using the forum search tool. Here's one thread:

SW900 / SW-LCD controller compatibility

I already have a spare sw900 LCD, would it be compatible with a controller that supports SW-LCD ? they both look very similar altough the 900 look a bit wider Thanks

endless-sphere.com

 

[amberwolf]

I've purchased an assembled DIY ebike with a 1500W rear motor and a 48V battery pack.

I have an unspecific inverter/controller which does not have any plugs/flying leads for the SW900. However I did note some solder/lead bits on the pcb marked RX, TX and what I think was 5V (I'll have to get my magnifier out to double check), there's currently no leads/cables soldered in to the identified solder points.

If the controller didn't come with a display or a connector for one, it's not very likely that it is compatible with *any* display. Even if it was, you would have to get the display specifically compatible to that controller, since displays and controllers are not generally intercompatible; not knowing what the controller is makes it tough to get a display that will work with it.


About the only thing a correctly-wired but incompatible display can do is turn the controller on and off, and display the battery voltage. It can't correclty change the controller settings (if it can change them at all, you won't know what you are changing, or what you're changing them to, and could make the system completely unusable, though I haven't seen this happen yet), and it can't display any information from the controller correclty, or at all, nor can it change assist levels or anything else.

Most displays have two data lines, a ground, a battery supply voltage, and a keyswitch / ignition return line for that voltage to the controller's LVPS voltage input, whcih turns the controler on when the display is turned on via it's power button. The display does not get 5v from the controller, it generates its' own from the battery voltage it gets from the controller.


What specifically do you need a display to do for you? If you make a complete list of what you need, we can probably suggest other devices you can use to do those things. (or a controller/display kit that replaces your existing controller).

 

[E-HP]

If the controller didn't come with a display or a connector for one, it's not very likely that it is compatible with *any* display. Even if it was, you would have to get the display specifically compatible to that controller, since displays and controllers are not generally intercompatible; not knowing what the controller is makes it tough to get a display that will work with it.

I added a display model to manufacturer list on my newb thread as a work in progress, so if there are any you are aware of....
I haven't added the bafang or tongsheng stock displays yet.

(work in progress)
Some common displays and associated controller manufacturers:
SW900 - DC MOTO CONTROLLERBYLITHIUMBATTERY
KD21C, KD51C, KD59E, KD716, KD718 - Lishui
S866, S886, M6T, LH100 - BrainPower
LCD3, LCD4, LCD5, LCD7, LCD8, LCD8H, LCD9R, LCD10, LED880 - Kunteng

 

[amberwolf]

Thanks, that should be helpful pointing people with that question to.

I don't know the models but I have at least three Kingmeter displays that are on Lishui controllers. (I don't recall any markings on them, so other than disassembly if you know how to tell, we can add them to the list).

I know that ASI (with various controllers and firmware) are compatible with some of the above displays, it's been posted here and there.

Some Sabvotons are display compatible, but I can't remember which displays, not sure if they are the same ones as the above.

If you haven't already, you might add a note that the Cycle Analyst is *not* a display like those (like I have posted in various threads--or you can copy one of those posts), for those that are looking for a display for their random controller that isn't in the list, since it's common enough for noobs to not understand how these things work.

BTW, if you are only editing teh thread and not making any new posts in it, it will be buried deeper and deeper over time; if whenever you edit it you add an "updated" post, it'll bump it up into the recently-posted-to threads list(s), which may help noobs run into it (not a lot of them since so few read anything, but some).

 

[extreme999]

Likely yes. What controller does your bike have (a pic of the label might help)? Displays are manufacturer specific for the most part. You can find info on them using the forum search tool. Here's one thread:

SW900 / SW-LCD controller compatibility

I already have a spare sw900 LCD, would it be compatible with a controller that supports SW-LCD ? they both look very similar altough the 900 look a bit wider Thanks

endless-sphere.com

Hello E-HP,

Here's the data plate on my existing controller.

 

[extreme999]

Just like to thank everyone for their input.

I've been back to the guy who sold me the bike to find out where he bought the kit from (Voilamart UK) and bought a new controller that is compatible with the SW900 display. On its arrival I can open up the controller to compare any differences, and to see if the spots on the original controller PCB marked TX and RX are the same.

Will report back when I find more information.

Thanks everyone

 

[E-HP]

Just like to thank everyone for their input.

I've been back to the guy who sold me the bike to find out where he bought the kit from (Voilamart UK) and bought a new controller that is compatible with the SW900 display. On its arrival I can open up the controller to compare any differences, and to see if the spots on the original controller PCB marked TX and RX are the same.

Will report back when I find more information.

Thanks everyone

That's great and will be very helpful to others in the future when you do that comparison (hopefully with pictures). Plus have a spare controller or two around is always good insurance.

 

[Bwilliams3523]

That's great and will be very helpful to others in the future when you do that comparison (hopefully with pictures). Plus have a spare controller or two around is always good insurance.

Just like to thank everyone for their input.

I've been back to the guy who sold me the bike to find out where he bought the kit from (Voilamart UK) and bought a new controller that is compatible with the SW900 display. On its arrival I can open up the controller to compare any differences, and to see if the spots on the original controller PCB marked TX and RX are the same.

Will report back when I find more information.

Thanks everyone

Hi ,
Fairly new to e-bikes. Building one now with the same controller you had originally and was also trying to install the SW900 but running into the same issue.
Just curious if I did in fact need a new controller in order to use the sw900?

 

[richj8990]

Hi ,
Fairly new to e-bikes. Building one now with the same controller you had originally and was also trying to install the SW900 but running into the same issue.
Just curious if I did in fact need a new controller in order to use the sw900?

Yes, a new controller that's 100% plug and play (and works) is worth every penny. Just make sure it's not a KT one.

 

[Bwilliams3523]

Thank you very much.

 

[docw009]

A KT controller with a KT display works better than the SW900 display and its controller that came with my 2019 ebikeling kit. Much better pedal assist control and the speedometer works.

One trap with the SW900 is there are different firmware versions sold for specific controllers, so if you buy one that is stand alone, it may have a different setup menu from your bike,