M5 LCD Replacement

doteyes9

New Member
I bought an Aventon Sinch a few weeks ago and already have broken the screen. When the bike is folded the screen is quite exposed, one unlucky movement later and the bike toppled with the display taking the force. I can still read voltage so am fine for now though :D

I and am wondering if anyone has any insight on the types of displays that are compatible with the motor controller used in the Sinch. After a little sleuthing, I'm almost certain that this motor controller is from www.jytjd.com, they have a similar part number structure, but that doesn't buy me much in finding out what protocols I can use. Another brand Nakto uses the M5 LCD and they use the Bafang pinout on the very same connector, see here, and some conversion kits with jytjd controllers use Bafang compatible screens. Normally when you see a 5 pin male Higo/Julet connector on a display it's for KT, other integrators that use this harness seem to use these types as well.

It seems like making assumptions here will be a crap-shoot, so when I get a chance I'm going to ohm-out the suspected +48V and GND pins against the battery, hopefully that will point me in the right direction. TxD, RxD, and Power Lock should be low voltage enough that swapping these won't fry anything but I won't have much ability to probe for these while maintaining the waterproof qualities of the connectors and controller. I could probe out the 1T4 harness and check if the pinouts match a certain advertised brand, but don't know where I could find those pinouts to check against.

For the curious, there is a serial number on the controller so no label pics, but the specs as follows:
Controller for brusheless motor
Voltage: DC48V
Undervoltage: 41 +/- 1V
Current-limiting: 22 +/- 1A
Brake Type: P-
Type: YCSL153-007-48T
Motor Phase Angle: 120

This is simply stuck to the side of the frame with a sticky foam pad. I also found subpar crimping on the interior wires between the battery connector and the controller. One lead on the red wire was exposed and not covered by the crimp housing. The entire crimped connection on the black wires was exposed with the plastic covering having warped, or possibly not shrunk all the way heat shrink.

There is also a Red/White/Grey/Black bundle heading to a 5 pin JST SM-5Y header on the controller, my guess is maybe this is a programming port common to Aventon bikes. ST-Link maybe?
 

yoyog

New Member
I have a similar issue for the Level. The display was damaged due to an accident on a new bike, and Aventon will not have stock for a long time. If anyone knows of a compatible replacement or has a display they're willing to sell, please let me know. Right now, the PAS/throttle is dead on a bike purchased a few weeks ago. Thanks.
 

doteyes9

New Member
So I purchased a "Nakto" M5 LCD from electriczip, shipping is slow right now though. No idea if this unit will actually have the waterproof connector on it as the bikes they are used for don't appear to have a waterproof harness.... So I bought a cable I can cut open and solder where needed inside the M5, or just rip the old one out. It looks like the Nakto display has a different firmware on it, it has the full range of settings available unlike the Aventon model, unsure what benefit this may bring though. The Nakto model also displays current, but I think the controller would need to support it, and who knows what ours can report!

I also found a seller on ebay who sells 3d printed covers for the M5 LCD, so hopefully I'll have some better shielding as well.

In an effort to upgrade the screen and have a backup (my clumsy ass will break it again) I ordered an Ebikeling waterproof TFT 750C off of Amazon, it's an APT TFT 750C terminated to the same 5 pin Julet connector used in our harnesses. Ebikeling sells waterproof upgrade kits using the same harness we do, I asked for their pinout and compared it to our bikes and it seems +48V and GND is where it should be on our harness, so I am hopeful this will be plug n play to some degree. This means that it is a safe assumption we follow the KT pin-out on our displays and that many aftermarket displays that support UART may be able to work here. I will report back if this works or not, but I'm betting it will :D

See this thread for a picture of the pinout.
 

yoyog

New Member
So I purchased a "Nakto" M5 LCD from electriczip, shipping is slow right now though. No idea if this unit will actually have the waterproof connector on it as the bikes they are used for don't appear to have a waterproof harness.... So I bought a cable I can cut open and solder where needed inside the M5, or just rip the old one out. It looks like the Nakto display has a different firmware on it, it has the full range of settings available unlike the Aventon model, unsure what benefit this may bring though. The Nakto model also displays current, but I think the controller would need to support it, and who knows what ours can report!

I also found a seller on ebay who sells 3d printed covers for the M5 LCD, so hopefully I'll have some better shielding as well.

In an effort to upgrade the screen and have a backup (my clumsy ass will break it again) I ordered an Ebikeling waterproof TFT 750C off of Amazon, it's an APT TFT 750C terminated to the same 5 pin Julet connector used in our harnesses. Ebikeling sells waterproof upgrade kits using the same harness we do, I asked for their pinout and compared it to our bikes and it seems +48V and GND is where it should be on our harness, so I am hopeful this will be plug n play to some degree. This means that it is a safe assumption we follow the KT pin-out on our displays and that many aftermarket displays that support UART may be able to work here. I will report back if this works or not, but I'm betting it will :D

See this thread for a picture of the pinout.

Please post your results. I suspect a lot of Aventon owners will be interested, especially in a compatible waterproof display. I'm wondering if a smaller, lower-profile model will work, such as this product. Thanks!
 

doteyes9

New Member
I have found that an off the shelf Nakto M5 display without Aventon firmware works just fine! The display isn't terminated to the Higo/Julet 5 pin male connector, but I can remove the back cover + wires of the old display and solder those onto the new one, or I can splice on the extension cable I bought.

Turns out the controllers used here are using Kingmeter 618U / J-LCD protocol. I verified this by hooking up the new and broken old display to a logic analyzer and found the protocols to match this library https://github.com/MichaelFabry/Ard...uino_Pedelec_Controller/display_kingmeter.cpp

The APT TFT 750C does not work and I do not know what I will do with this. I may try to reverse engineer it, following the 850C board's custom firmware, and add this protocol in. The protocol is simple but reversing the board is not!

The new display has many more settings, see https://www.e-bikes.com/pages/nakto-ebikes-lcd-control-panel-instruction
Mine is configured as follows:
P01 - 2
P02 - 1
P03 - 48V
P04 - 10
P05 - 1
P06 - 4
P07 - 16
P08 - 40
P09 - 1
P10 - 2
P11 - 1
P12 - 1
P13 - 12
P14 - 15
P15 - 41.0
P16 - N/A
P17 - 0
P18 - 100
P19 - 1
P20 - 2

I messed around with P05 and found out that some of the higher level PAS settings (This display went alphanumeric on me!) just made the bike drive itself forward, way faster than the walk mode!
P06 is normally in inches, but in this instance it maps to the default tire settings available. Follow the order in your Aventon user manual from smallest to largest, number 4 is 24". The 618U protocol has the display state wheel size every packet, I confirmed these map between displays. The kingmeter library above also shows this order.
I'm uncertain if P07 is actually 16, I need to do some real world testing, but this setting doesn't leave the display and Shengyi doesn't list this specific model online. However, their similar models all have 16 pole pairs, so I believe this is correct.
P11 is essentially number of magnet counts before PAS kicks in. I haven't done any real world testing, but I didn't notice any difference here. Messages in this protocol are only sent every 1/2 second, so that doesn't really buy you much anyway.
P12 keeps PAS from kicking in strongly, it's nice to be able to set this depending on ride.
P14 makes no difference here! The controller we have internally limits to 22A. The display does not echo this setting back to the controller, I did not see any changes in the packets. The controller also does not report current to the display, this field was always 0. I set this to 1A and noticed no difference.
P15 is to match the controller.
P17 enabled would allow you to have the motor cruise you at speed without pedaling. I don't care for this style.
P18 would be used as a ratio if your tire sizes don't line up to the available ones.
P19 lets PAS 0 be selected.
P20 is usually listed as "Alternate" or "Standby" in product listings for this screen and others with the same style settings where P20 decides protocol. I think this display is a Kingmeter Nokee-U knock-off, so it would make sense to not broadcast the name of the protocol.

All in all, the display in our system is really only displaying speed and turning off PAS if you're up to speed. Lameeeeeeeeee.
 

yoyog

New Member
Thanks. Just to make sure I understand your post, the Nakato display will require soldering because it lacks a compatible plug for the Aventon wiring harness, correct? Otherwise, it's plug and play? Also, do you have any thoughts as to whether KT-compatible displays, such as this one, would work? I realize it's impossible to know for sure without testing the display.
 
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doteyes9

New Member
The KT-LCD-4 is most likely not compatible, but I could be wrong. It all depends on what protocols it supports, which the manufacturer should be able to confirm. Ask for the "J-LCD Protocol". Some may also be able to terminate it correctly, just ask! I found that APT was responsive but ultimately I don't think they would support this protocol, but they do support 5S.

In general, if you want a purely off the shelf solution just stick with the M5 display from Aventon. Otherwise you will likely not find the right termination. If you can accept that, then the KM5S (Old FW), S-LCD, and J-LCD from King Meter should also work. The Nakto branded M5 display was not terminated with the right connector, and the wires are over-molded to the back panel, so I was going to swap those out, it's a simple soldering job.

I'm also debating buying an EggRider since I think the Lishui model will be compatible with our bikes. Apparently the Lishui Forerider app is compatible with J-LCD display bikes. It will also be terminated correctly for our bikes, I think. I'm starting to think Aventon swapped the TX and RX lines though, so I'm reviewing my test setup to see if that's true.
 

yoyog

New Member
Thanks. Great information. Let me know what you find out about the Eggrider and whether TX/RS is swapped. I'm sure you've seen this, but Eggrider offers to look at photos of controllers for compatibility.
 

yoyog

New Member
My choices are pretty much non existent now
Tell me about it. I've been waiting on Aventon to replenish stock to fix a busted display for weeks now. And Aventon clearly has stock of the displays for warranty issues. Would it kill them to make a few available for purchase for owners? I understand there are supply chain issues, etc., but this is bordering on ridiculous.
 
Tell me about it. I've been waiting on Aventon to replenish stock to fix a busted display for weeks now. And Aventon clearly has stock of the displays for warranty issues. Would it kill them to make a few available for purchase for owners? I understand there are supply chain issues, etc., but this is bordering on ridiculous.

I don't have my Pace 500 yet, (just shipped) IMG_20200805_144330_6[1].jpg but this is for another ebike (DJ Super bike) I have that uses the same display that has a problem... but the guy literally dhl'd it to me from china last week... Took 5 days to get here.
 

yoyog

New Member
I don't have my Pace 500 yet, (just shipped) View attachment 61413 but this is for another ebike (DJ Super bike) I have that uses the same display that has a problem... but the guy literally dhl'd it to me from china last week... Took 5 days to get here.
That's awesome. Can you provide a link?

Aventon now has stock on its website, BTW. I spoke too soon.
 
That's awesome. Can you provide a link?

Aventon now has stock on its website, BTW. I spoke too soon.

A link to the bike? This was a warranty covered part so the seller of the bike sent it to me from his supplier, I was just saying they are readily available... I did notice that the control switch attached to it, is different than on the pace 500
 

yoyog

New Member
A link to the bike? This was a warranty covered part so the seller of the bike sent it to me from his supplier, I was just saying they are readily available... I did notice that the control switch attached to it, is different than on the pace 500
Ah, ok. I thought you bought the display from a third party. I've looked for alternative display suppliers with no luck. I'm just happy that Aventon has stock again, although I wish there was smaller, less delicate option available.
 
Ah, ok. I thought you bought the display from a third party. I've looked for alternative display suppliers with no luck. I'm just happy that Aventon has stock again, although I wish there was smaller, less delicate option available.

I noticed this..
Look up Nakto m5 display...it seems to be the same as on the Pace 500 and maybe a little cheaper.
 
Yeah, I know about Nakato, but those displays have the wrong termination plug for Aventon. See prior posts in this thread.
Oh ok...Sorry about that...well this might be different too then since it also has a headlight lead wire as well as a different up and down and M button lay out than the pace..it has all of them on top with the M between the 2 arrow keys
 

dbodero

New Member
I’ve got a similar problem. My bike tipped over while folded on a carpet floor and busted the display. I tore out the Julet 5 pin connector and the M5 button. Does anyone have any solid idea what the gear reduction and number of magnetic poles on the motor is? I might just buy a display from motowoks and solder on the Julet connector.
 

Bigal1463

Well-Known Member
I have the Aventon Pace 500 and the odometer reset to 0 miles when I reached 1,300 miles. it is out of warranty, though was wondering if anyone else has had the same problem. I have been incapacitated for a week now and probably for at least another week or more, and have not been able to try it out yet. Is this issue going to affect anything else?