USB interface into Bosch crank computer?

halfer

Esteemed Pedelecer
Hi all

In some recent research, I found that diagnostic equipment for Bosch crank drive systems uses a USB interface. I'm inclined to think this is the case for the current style of handlebar computer (HMI), as well as the new kind featuring a USB socket. For the old kind, I speculate that there is a USB socket either inside the HMI casing, or on the computer PCB in the drive itself (see here).

If this interface exists, it could help Bosch owners toggle the metric/imperial display, modify the speed limiter, record real-time speed and battery state information, etc. However, there is no information about this on the web that I can see.

Does anyone know how diagnostic tools attach to Bosch systems, and whether it does indeed employ a USB interface? Anyone got any detailed pics of the HMI or drive motherboard?
 

Blew it

Esteemed Pedelecer
Jun 8, 2008
1,472
97
Swindon, Wiltshire
Phew!

The limited knowledge I have regarding the Bosch system suggests changing the read-out on the HMI to show "miles" is through interrogation of the HMI itself, with a supplementary handlebar baseplate acting as a dongle. I somehow doubt a service center would be expected to dismantle anything to achieve a country specific read-out.

Regarding the Road speed at which the assistance ramps down. I think it is unlikely that the assistance speed can be set higher electronically. The reduction gearing within the drive is set so that road speed is closely related to the peak efficiency of the motor....close to maximum voltage related motor armature speed. I believe there is now a Bosch 45 (45 kph) version for the German high speed category. If this was achieved by a simple firmware upgrade, the motor would run out of steam long before reaching a road speed of 45 kph. For this reason I suggest the Bosch 45 unit has a different motor/pedal-shaft reduction ratio.

The best place to glean information on the Bosch drive, including diagrams of the HMI circuit, is the German Pedelecs site on the link below.

Google Translate
 

morphix

Esteemed Pedelecer
Oct 24, 2010
2,163
119
Worcestershire
www.cyclecharge.org.uk
Hi all

In some recent research, I found that diagnostic equipment for Bosch crank drive systems uses a USB interface. I'm inclined to think this is the case for the current style of handlebar computer (HMI), as well as the new kind featuring a USB socket. For the old kind, I speculate that there is a USB socket either inside the HMI casing, or on the computer PCB in the drive itself (see here).

If this interface exists, it could help Bosch owners toggle the metric/imperial display, modify the speed limiter, record real-time speed and battery state information, etc. However, there is no information about this on the web that I can see.

Does anyone know how diagnostic tools attach to Bosch systems, and whether it does indeed employ a USB interface? Anyone got any detailed pics of the HMI or drive motherboard?
Buy a Raspberry PI and then you got a USB interface controller for it ;-) You just need an LCD then or you could maybe use bluetooth fone to communicate to Raspberry heh
 

eddieo

Banned
Jul 7, 2008
5,070
6
Are you that bothered regards Kim readout as I'm not to be honest...not as if the speed range that wide. I don't think there is a simple way of interigating software and de restricting, as there are plenty of fiddlers over on German forum! Your warranty will also fly out the window I would suspect

Justebikes are the only ones who would know over here I would think, as James has said before I believe, that they have the interface.
 

NRG

Esteemed Pedelecer
Oct 6, 2009
2,592
10
If the readout is in Km you may be able to simply adjust the wheel size circumference set in the computer to compensate IE: What ever it is set to multiply it by 0.62 and enter in the new number...the readout will now be in MPH...
 

halfer

Esteemed Pedelecer
Blew it, some enterprising German mechanics have found how to set up a standard Bosch system for off-road speeds. The basis is moving the magnetic sensor on the rear wheel so it reads the rotational speed of the crank instead, which can be some 30% of the wheel speed.

The first video here is a road test, and the second is how they did it. They're in German, but once they demo the movable sensor, the basis can be understood. One for post-warranty, indeed Eddieo!
 

eddieo

Banned
Jul 7, 2008
5,070
6
Old news...That was with the original bosch I would think ...Bosch have prevented this being done with later releases...

at end of link:

update

Bosch changed the controller software of the drive unit to look for this change! If your motor came after April 2012, then you have the modified version already. If you try this hack, you will get an error message of 102, and the speed of the bike will be limited to 15 km/h. Currently we don’t have any solution to change the speed limit of the drive unit!
 
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Blew it

Esteemed Pedelecer
Jun 8, 2008
1,472
97
Swindon, Wiltshire
Blew it, some enterprising German mechanics have found how to set up a standard Bosch system for off-road speeds.
Hi Halfer, yes I'm aware of that mod. On early Bosch systems the wheel magnet could be removed to achieve a higher assist speed, same as we do on the Tonaro machines. Later Bosch machines will default to the lowest assist level, ECO 1, if the magnet is removed.

As you correctly say, if the wheel magnet is moved to the back of the pedal shaft, and the sensor repositioned to align with it, the assist speed is related to cadence rather than rear wheel rotation speed. There is a KTM machine here in Swindon modded in this way....the guy is now looking for a bigger battery! :rolleyes:

Really speaking, I think it would have been better for you to purchase a machine designed for the German high speed class rather than interfering with your current machine. ;)

Anyway, have fun with the machine.
 

carpetbagger

Esteemed Pedelecer
Nov 20, 2007
744
18
blackburn
you should have got a Panasonic Kalkhoff, change the motor sprocket...10t,12t,14t...a 16t would be interesting and only 10 mins to change......