M5 LCD Replacement

rcdanner

Member
I have had 4 Aventon Pace 500 ebikes over the past two years. ALL 4 Displays reset after X miles. This is well known problem for Pace 500 Displays. I received replacement Displays on 3 of the ebikes. 4th Display received monetary rebate from Aventon. Reset Display works fine. Just know that Odometer may reset again. I keep actual mileage on database. So no problem. The 3 Replaced Displays have wierd 'feature' of displaying both KM/Mi icons on Trip B. However, only miles are actually displayed in Trip B. All other Display functions work normally.
 

Bigal1463

Well-Known Member
Thanks rcdanner, I appreciate any and all responses, especially knowing that it has happened to others and it appears to be an issue that I will have to live with. I can deal with it.
 

BillyBob74

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.
The Factory Aventon "Level" M5 Display appears to be setup so one cannot get to any of the higher numbered settings. I would love to be able to reduce the amount of "assist" and there appears to be a setting in the Natko for doing that. Do you know who makes the display and/or controller Aventon uses and if there is a way to get to those extra parameters? Thanks.
 

Kumar

New Member
Region
United Kingdom
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.
I have a shenmilo mx01 1000w electric bike and the lcd m5 display broke off all the wires .Do you know which wire goes into which slot so i can solder it back or where i can buy a like to like display