DIY mtb telemetry system

alek-91
Posts
45
Joined
3/12/2021
Location
IT
5/14/2021 6:24am
Finally got the case... on the 3d cad was smaller 😅😅
Anyway everthing fit like a charm, so already quite happy with that, still room to improve, at least from width side i need to go down 10 mm at least. Thinking about different batteries.




Primoz
Posts
4621
Joined
8/1/2009
Location
SI
5/14/2021 7:31am
Next time add some tabs/holes to mount the box using zipties or a gear strap Smile
Symion
Posts
1
Joined
7/25/2021
Location
DE
7/25/2021 3:59am
Hey @alek-91 any news?
Primoz
Posts
4621
Joined
8/1/2009
Location
SI
7/25/2021 9:10am
Yeah, I was just thinking about this project yesterday morning to be honest and wondered what's going on.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
8/9/2021 11:28pm
Hello everyone,
I had several weeks of slowing down on the project since i was able to ride more and program less. I was able anyway to get some improvement on the hardware side (i changed the switch on the handlebar casue the old one at first crash it broke and also a shorter GPS antenna)
Also i was pushing a little on the data anlaysis program, implementing self recognizing closed lap, gps maps and some other stuff. Next step will be sure a smaller case and more vibration insulated electric part. On mtb no problem at all, but on motocross bike it just shut down due to high vibration.
On this picture one lap of three subsequent laps here aorund my place in the woods. This feature is really nice to chec different setting and onverlay data



1
Jonathan.F
Posts
1
Joined
9/2/2021
Location
Saint Johns SE
9/2/2021 2:11pm
alek-91 wrote:
Hello everyone, I had several weeks of slowing down on the project since i was able to ride more and program less. I was able anyway...
Hello everyone,
I had several weeks of slowing down on the project since i was able to ride more and program less. I was able anyway to get some improvement on the hardware side (i changed the switch on the handlebar casue the old one at first crash it broke and also a shorter GPS antenna)
Also i was pushing a little on the data anlaysis program, implementing self recognizing closed lap, gps maps and some other stuff. Next step will be sure a smaller case and more vibration insulated electric part. On mtb no problem at all, but on motocross bike it just shut down due to high vibration.
On this picture one lap of three subsequent laps here aorund my place in the woods. This feature is really nice to chec different setting and onverlay data



First of all, real nice work Alek. Im just curious if you still find 100hz enough? Have you had any success with the bluetooth, it would make it a whole lot easier to see data between single runs. Any other updates/upgrades?
Primoz
Posts
4621
Joined
8/1/2009
Location
SI
9/2/2021 10:08pm
The amount and type of data is a lot more suited to a computer if you ask me. This isn't Shockwiz level of tuning, where it tells you 'your compression is yellow, change it by 1 or 2 clicks. You have to find the events on your own.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
9/9/2021 11:02pm
alek-91 wrote:
Hello everyone, I had several weeks of slowing down on the project since i was able to ride more and program less. I was able anyway...
Hello everyone,
I had several weeks of slowing down on the project since i was able to ride more and program less. I was able anyway to get some improvement on the hardware side (i changed the switch on the handlebar casue the old one at first crash it broke and also a shorter GPS antenna)
Also i was pushing a little on the data anlaysis program, implementing self recognizing closed lap, gps maps and some other stuff. Next step will be sure a smaller case and more vibration insulated electric part. On mtb no problem at all, but on motocross bike it just shut down due to high vibration.
On this picture one lap of three subsequent laps here aorund my place in the woods. This feature is really nice to chec different setting and onverlay data



Jonathan.F wrote:
First of all, real nice work Alek. Im just curious if you still find 100hz enough? Have you had any success with the bluetooth, it would...
First of all, real nice work Alek. Im just curious if you still find 100hz enough? Have you had any success with the bluetooth, it would make it a whole lot easier to see data between single runs. Any other updates/upgrades?
Hi Jonathan,
with the analog sensors i am able to reach 500 Hz, but for my level of riding i was not able to catch big differences in the data logged, neither further indication on the analysis,so i'm still happy with 100 since is also more easy to handle as dimension file and synchro with GPS
alek-91
Posts
45
Joined
3/12/2021
Location
IT
9/9/2021 11:05pm
Primoz wrote:
The amount and type of data is a lot more suited to a computer if you ask me. This isn't Shockwiz level of tuning, where it...
The amount and type of data is a lot more suited to a computer if you ask me. This isn't Shockwiz level of tuning, where it tells you 'your compression is yellow, change it by 1 or 2 clicks. You have to find the events on your own.
Sure shockwiz is more user friendly and oriented respect something like this, but i don't even know what is measuring , how they convert pressure in stroke without knowing the fork (is there any suspension information form before to use), initial pressure and so on,and more important no idea which is the algortihm that gives you the final indication. Can be a random that tell you to close or open two clicks, since no drama can happens

alek-91
Posts
45
Joined
3/12/2021
Location
IT
9/9/2021 11:08pm
Summer season is ending, and some time to spend in front of PC is coming. I update the case reducing a lot the dimension and adding cable tie routes to fix on the bicycle.I also thinking to change the small opening for sd card with a magnetic one, so it should be easier to open and close. I just hope willl be strong enough.
Only one big doubt remains, i.e. if change the cable entry with a connector like byb logger or aim, or keep the cables out like it is now.



1
Primoz
Posts
4621
Joined
8/1/2009
Location
SI
9/10/2021 1:27am Edited Date/Time 9/10/2021 1:28am
Primoz wrote:
The amount and type of data is a lot more suited to a computer if you ask me. This isn't Shockwiz level of tuning, where it...
The amount and type of data is a lot more suited to a computer if you ask me. This isn't Shockwiz level of tuning, where it tells you 'your compression is yellow, change it by 1 or 2 clicks. You have to find the events on your own.
alek-91 wrote:
Sure shockwiz is more user friendly and oriented respect something like this, but i don't even know what is measuring , how they convert pressure in...
Sure shockwiz is more user friendly and oriented respect something like this, but i don't even know what is measuring , how they convert pressure in stroke without knowing the fork (is there any suspension information form before to use), initial pressure and so on,and more important no idea which is the algortihm that gives you the final indication. Can be a random that tell you to close or open two clicks, since no drama can happens

During setup it measures the pressure of a fully deflated spring when it is fully extended and fully compressed. Through the change in pressure it defines the compression ratio.

The spring characteristic curves are not linear for air springs, but the Shockwiz setup procedure only defines the two end points, so it can not know where exactly in the travel the spring is. It can only know if it's fully extended or nearly so or if it's fully compressed or nearly so or somewhere roughly in-between.

Because of that limitation I'm guessing Shockwiz does not look at absolute positions, but looks at events. So do you reach full travel, roughly where in the travel you sit most of the time (as it does give suggestions for sag adjustment) sag wise and how far from that you move on certain events, are there oscilations on rebound strokes around the sag (under damped) or a slow return to the sag position (overdamped), are there a lot of deep dive events (not enough high speed compression), are there events with a lot of slowly moving travel and staying there (too much low speed compression), etc. etc.

With LVDTs or some other travel sensor you have a much more detailed set of data,b ut you also need to know what you're looking at on another level.



Regarding the case, if it's going to be 3D printed, make the tabs under the cable ties (the part fixing it to the frame) thicker, if there's any weight inside the case. Thin section could fall off.

And maybe add another central mounting option that is wider and useable for gear straps (liek OneUp's EDC Gear Strap)?
alek-91
Posts
45
Joined
3/12/2021
Location
IT
10/14/2021 2:01am
Rev2 of the case. It is slimmer and better organised inside. Now is big like an iPhone X (5.6 inches) and is much stiffer with wall thickness of 3 mm. Moreover i added cable ties holder and flippable side door for SD, with self closing system (magnets)




3
Fawful
Posts
1
Joined
10/17/2021
Location
Saint Johns, PA US
10/17/2021 5:21am
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to run at 100hz and not 50hz which according to the datasheet is the max update rate. I am working on a real-life T-rex jump game (the one which starts when chrome is without internet connection). If you have any documentation or hints on how to set it up above 50hz it would be really helpful.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
10/18/2021 7:48am
Fawful wrote:
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to...
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to run at 100hz and not 50hz which according to the datasheet is the max update rate. I am working on a real-life T-rex jump game (the one which starts when chrome is without internet connection). If you have any documentation or hints on how to set it up above 50hz it would be really helpful.
write me privately i will share with you what i have found about that argument.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
10/22/2021 2:23am Edited Date/Time 10/22/2021 2:24am
New case fit quite well on the bike. Also screwless design make me proud




3
10/22/2021 2:10pm
What an excellent project. I'm into running numbers and would love a chance to make sense of the observables.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
10/28/2021 11:39pm
Since the winter is starting again i wanted to make another step on this project. Right now I can run both analog signals (linear potentiometers front and rear) and laser sensors, but now i would like to go wireless with the laser sensor
I found out this board
https://www.gilisymo.com/sensors/22-ls53l1bt.html
that has the same sensor i used but also accelerometers and bluetooth. I already contacted the guy and he will send me more information about the limitation of the board etc in the next few days.
My idea is :
- two of this board for acquiring suspension travel (for sure with lower frequency than now ) with their own button batteries
- small acquisition board with the arduino as it is now but with smaller lithium battery since no sensor power supply is needed.
the objective is to have much smaller and clean setup than now, even if accuracy will be for sure less.

Primoz
Posts
4621
Joined
8/1/2009
Location
SI
10/29/2021 12:00am
What about the timing and synchronisation when going wireless?

There's a reason why measuring equipment is very rarely (if at all, can't remember anything that is wireless at this moment) not wired...
alek-91
Posts
45
Joined
3/12/2021
Location
IT
10/29/2021 3:37am
It will depend on the buffer size of sensor bluetooth, this is one information still missing from the manufacturer. If it can handle a circular buffer at 60 Hz that make synchro with the 10 hz GPS probably the delay is not critical. I'll keep you updated on this.
nollak
Posts
77
Joined
11/27/2020
Location
DE
10/30/2021 5:24am
Is 60Hz sufficient for good data?

I would assume that 100Hz should be the minimum although I would probably go up to 200 or 400Hz on linear potientiometers at least.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
11/2/2021 8:55am
Hi Nollak,
Frequency limit is quite low, it's true but i can anyway run with potentiometer at 200 hz as it is now. I would like anyway to have position record (not for damping tuning) but more for kinematics and sag analysis of the bike during the run. I am building a kinematic program that will compute bicycle position and dimension like antisquat etc based on suspension travel, and with that the 60 hz system should be enough
When i want to optimize damping i will run with analog stuff, both system will be compatible.
1
nollak
Posts
77
Joined
11/27/2020
Location
DE
11/3/2021 2:22am
Ah ok, I thought you were doing the damping optimazation with the sensor.

But shouldn't the analog potentiometers be enough as one source of information? Or are they not calibrated for travel?
1
alek-91
Posts
45
Joined
3/12/2021
Location
IT
11/3/2021 6:28am
Yes potentiometer are calibrated in distance bur they have a lot of wires and not always i want to optimize damping, in the end once you run in similar condition with similar air spring rate you will not change so much the damping but you still want the telemetry. I want to keep the setup as it is now and have also a light setup with just wireless sensor.
As you can see with both potentiometer remains quite messy

1
nollak
Posts
77
Joined
11/27/2020
Location
DE
11/3/2021 12:19pm
Yeah that looks a bit messy :D

Do you have a link to the potentiometers? I am thinking about doing something similar with potientiometers only over the winter.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
11/4/2021 2:38am
nollak wrote:
Yeah that looks a bit messy :D Do you have a link to the potentiometers? I am thinking about doing something similar with potientiometers only over...
Yeah that looks a bit messy :D

Do you have a link to the potentiometers? I am thinking about doing something similar with potientiometers only over the winter.
i bought these from china. Quite cheap and they works quite good.
http://www.htc-sensor.com/products/212.html
cost around 60-80 € depends on the stroke length.
1
nollak
Posts
77
Joined
11/27/2020
Location
DE
11/4/2021 3:57am
Perfect, thanks.

I think for some prototyping they should work out nicely :D
alek-91
Posts
45
Joined
3/12/2021
Location
IT
11/10/2021 3:15am
Sensor arrived… soon first try


1
alexkonakov
Posts
3
Joined
11/9/2020
Location
La Canada Flintridge, CA US
12/7/2021 6:46pm
Fawful wrote:
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to...
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to run at 100hz and not 50hz which according to the datasheet is the max update rate. I am working on a real-life T-rex jump game (the one which starts when chrome is without internet connection). If you have any documentation or hints on how to set it up above 50hz it would be really helpful.
alek-91 wrote:
write me privately i will share with you what i have found about that argument.
Just stumbled across this thread myself and am looking to use the same sensor, also interested in how you got it running at 100hz rather than the 50hz max in the specsheet.
alek-91
Posts
45
Joined
3/12/2021
Location
IT
12/9/2021 8:01am
Fawful wrote:
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to...
Hello, I just found this forum even though Im not a cyclist. What I did find very interesting however was how you got the vl53l0x to run at 100hz and not 50hz which according to the datasheet is the max update rate. I am working on a real-life T-rex jump game (the one which starts when chrome is without internet connection). If you have any documentation or hints on how to set it up above 50hz it would be really helpful.
alek-91 wrote:
write me privately i will share with you what i have found about that argument.
Just stumbled across this thread myself and am looking to use the same sensor, also interested in how you got it running at 100hz rather than...
Just stumbled across this thread myself and am looking to use the same sensor, also interested in how you got it running at 100hz rather than the 50hz max in the specsheet.
I did not managed completely by hardware cause the ST sensor has some limitation due to the timing of ranging. In short mode measurement you can reach max 66 Hz frequency by hardware. Then by software i used linear interpolation to reach 100 Hz frequency, instead to use directly a 100Hz and have repeated values. I run a comparative with analog sensor at 100 hz and result was pretty good for my application.
alexkonakov
Posts
3
Joined
11/9/2020
Location
La Canada Flintridge, CA US
12/18/2021 10:44pm
What sort of format are you using for your suspension data? I got my sensor to write to a .csv file but other than simple graphing applications I'm unable to get my data imported to these motorsport data analysis programs such as "Danas" which you're using.

Post a reply to: DIY mtb telemetry system

The Latest