Remote dropouts.

Hola amigos.
Just found this post on Reddit. And this is the most informative post I have seen regarding the remote dropouts that some riders have.

This is NOT a solution to this problem, and it dose not help the people having serious dropouts, making the board slam on the brakes hard. But it explains why people get Antenna and battery dropouts on the LCD screen.

Got my C GT Yesterday, and right away when I tried the board the LCD screen dropped out, not showing the signal bars and batterie status, but the throttle worked fine....Was a bit scared I would have problems because of this. But had 0 dropouts on the control of the board. Even if the batterie indicator drops out all the time, Im still in full control of the board.

So would recommend riders to read this:




So apparently the board have a 2 system signal, one for the LCD info. Bluetooth. And a RC connection for the control of the board. This info made me feel a lot better. Since I never had a disconnect from the board, only from the LCD screen. But time will show. Only been riding for 2 hours yet. AND I LOVE IT, ITS SOOOOOO AWESOME.


Side note: I aslo see that you only need to pair the remote 1 time. And after that it pairs itself, when turning on the board, then the remote, they will pair automatically. Guess its the same as pairing a bluetooth headset to your phone...when its paired once, it pairs to the phone by it self when turned off and on again after that.
I bought mine from Evolve UK, And they had a test-ride before shipping out to me, so my control was already paired when it arrived. I just turn on the board and remote, and before I could hold down the left button to pair it was already done. So no need to pair the remote before using it


Cheers Kenneth

 

yea how do we know this ? - sounds good in theory and I don't disagree it makes sense but we haven't seen any thing conclusive that they are also using an RC style radio. Wiztecy found an FCC filing and posted it somewhere on this forum but I think it only mentions a bluetooth device - nothing about RC.

Now having said that - it could explain the erratic behavior (from one riding / boot up session to the next) which we have also seen in RC, more so with the earlier digital protocols. (the dreaded lock out which you typically didn't recover from)

Also see "hold mode" in the last paragraph below - this is similar to the stuck throttle that myself and Wiztecy and Evolveinla have experienced

DSM (one of Spektrum's original rc control protocols) basically picked two channels and would flip from one to the other if it got interference - this was later improved with DSM2, DSMX and similar protocols used by Futaba, Hitec, Jeti etc.

The problem was on startup it could pick two channels very close together where both could experience interference and a drop of signal for an extended time.

Here is some info on the original DSM spec:

Introducing the New DSM System from Spektrum: Spektrum - The Leader in Spread Spectrum Technology


THE BENEFITS OF DSM

Spektrum’s DSM system eliminates all types of radio interference, including model-generated noise from motors, ESCs, bad bearings, etc. and from outside sources like pagers, cell phones, wireless computer systems and other RC radio systems, and offers these benefits:

• No more waiting for an open frequency—just turn it on
• Ultra fast 5.6ms response time
• No tuning or maintenance to perform (ever)
• Built-in fail-safe drives servos to preprogrammed position if signal is lost
• Ultra precise 4096 bit resolution
• Operates on international 2.4GHz ISM band so no need to change bands when traveling to international races
• Short 8.5” or 3.6” receiver antenna length and 3.5” transmitter antenna length
• 40% less current draw with the transmitter means 40% more battery life
• Telemetry ready for rpm/speed, temperature, battery voltage, lap times and signal strength
• Legal for most racing organizations including ROAR, NORRCA and IFMAR
• Available for most popular 3-channel module radio systems for easy, inexpensive conversion to DSM technology

FHSS VS. DSSS

There are two primary types of Spread Spectrum technology— Frequency Hopping (FHSS) and Direct Sequencing (DSSS). FHSS systems transmit a narrow band signal and rapidly jump from one frequency to the next spending a few milliseconds on each frequency. DSSS systems transmit on a single selected frequency but on a very wide band. Only a small portion of that band is used for specially encoded information. Originally, Spektrum engineers started their development with FHSS-based systems because they were relatively easy and inexpensive to develop. However, it was soon discovered that FHSS had several limitations that would prevent it from being the optimal solution for RC.

While more difficult and costly to develop, our engineers began experimenting with Direct Sequencing Spread Spectrum and optimized the modulation scheme to overcome critical response and re-link issues. In addition, DSSS offered 18dB increase of processing gain for significant improvements in range. With years of development and testing the DSSS modulation scheme was optimized for RC car use and Spektrum’s DSM system was born.

How DSM Works
Collision avoidance eliminates the possibility of more than one Direct Sequencing Spread Spectrum system from transmitting on the same frequency. Here’s how it works: When the transmitter is turned on, the system scans the 2.4GHz band looking for an open channel. 79 channels are available. When an open channel is found, the system locks in and transmits on that channel. This process takes about 2 seconds. In the unlikely event an open channel is unavailable, the transmitter continues to scan without emitting a signal until an open channel becomes available. The transmitter will remain on that selected channel until it’s turned off. Each individual module is factory programmed with its own unique serial code called GUID (Globally Unique Identification code). Once a receiver is programmed to a specific module (called binding) the receiver will only recognize that module ignoring signals from any other sources. And with over 4 billion possible GUID codes, it’s virtually impossible for a receiver to listen to anything other than its bound transmitter.

When the receiver is turned on, it scans the 2.4GHz band and searches for its specific transmitter’s encoded signal. When found, it locks in on that channel. If the signal is lost, the receiver goes into a hold mode, positioning the servo to a preset fail-safe position until the signal is reacquired. If the receiver is turned on before the transmitter, it will continuously scan the band until the encoded transmitter signal is present. During this period, the receiver drives the servos to the preset fail-safe position. All Direct Sequencing Spread Spectrum systems are required by the FCC to incorporate active collision avoidance, making it impossible and illegal for more than one transmission on a single frequency.


EDIT: - heres the latest on the Evolve remote / radio: Evolve - radio is using nRF24L01

 

very interesting, but no solution then for now..!!

 

Yea - still wish they would go with something other than the NRF24L01 transceivers - (like proven RC above or even Bluetooth) - we have debated this a lot - but I still Fly / drive RC and have other Bluetooth devices and don't get the issues like some are still seeing on their remotes/boards - the strangest thing for me is some have no issues, some have issues fixed by hardware swaps and some continue to have issues (so whats the variable? - unless multiple causes) - interesting thread about twisting the motor wires

 

Evolve support is sending me a new remote.. doubting that this will solve the issue

 

It certainly may - as it has for some good luck with the replacement

 

Evolve Bamboo GT Skateboard uses 2.4GHz ISM band
DJI Phantom 3 Pro Quad (Drone) remote controller uses 2.4 GHz to 2.483 GHz
& 2.4GHz ISM For Video transmission
Any chance they could conflict interfere with each other?

 

^^ yep - thats a busy band - also includes BT and BTLE