After the old powerstep based motor controller i improved the idea of an open source force feedback interface for direct drive wheels and other simulation interfaces with high torque demand in a modular way

OpenFFBoard consists of a simple STM32F411 based usb interface with defined pins for SPI, buttons, leds, encoder input…

Take a look at the full development story on hackaday.io

A TMC4671 based motor driver which is also developed in this project as a reference can drive 2 phase steppers, 3 phase servos and DC motors at up to 70V DC and over 25A.
It has an active anti backfeed diode circuit for use with power supplies and a brake resistor mosfet included. It also features highly accurate current sense amplifiers and voltage sense dividers.

Its possible to stack the FFBoard interface on top of up to 3 of these TMC motor drivers for a compact setup.

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Short video in action:

OpenFFBoard Assetto Corsa FFB Test raw from Gigawipf on Vimeo.

Based on the popular DPS5005 Module i have created a 3D printed power supply (Thingiverse STL).

These modules can also be controlled via usb with modbus. A python example is available on my github.
This allows for automatic measurements and live readouts.

A 32V old kodak power supply is fitted in the bottom of the case. For the fan a standard DC-DC buck converter was used.

The temperature stays reasonably cool when used with a fan while running at over 100W . The limiting factor here is the power supply and the 5A limit of the module. These modules should not be used without a bit of thought about airflow as the switchig mosfets can get very hot in enclosed spaces.

I wondered why i have never seen anyone making music with a siren so i had to try it myself.
It was started when i browsed thingiverse and found a nice little siren model and i had all the parts i needed around.

The interface is based on an arduino micro as a midi interface to generate a ppm signal to use with hobby escs based on incoming notes.
If the esc and motor respond quickly enough and hold the speed well it can be used as a (probably terrible) instrument.
I was pretty surprised how well it actually workded and expected it to be much worse.
The speed is not really regulated other than by the calibrated esc and a fixed voltage source and the spin up and down time depends on the inertia of the rotor and how good the esc can brake.
Fast quadcopter escs and a strong motor are preferred for this.
Some escs offer closed loop speed controlling which would be even better.
I have used a cheap racerstar lite 20A esc running blheli and a spare 2204 multistar elite 2300kv motor.

This is my first real quadcopter build.

It is based on the Diatone 250 frame, some Multistar elite 2204 2300kv motors and the naze32 flight controller.

The Naze32 rev5 does not work with sbus without an additional inverter so i first tried to just use pwm.

Even without flying i noticed an annoying delay in the throttle response so i tried to use sbus anyways and bypassed the inverter in my x8r.

I will still have to change the flight controller later as i want to use s.port telemetry, which won’t work with the naze32 rev5.

To save a bit weight it should also be a good idea to clean the wiring and switch to the smaller frsky x4r receiver.

Pretty much finished now:Even with stock pids it hovers fine:

Some years ago i loved smartpropoplus, a software that lets you use any rc remote with trainer port on you soundcard to emulate a windows gamecontroller.

While playing around with rtl-sdr i found out that my receiver can receive the 35mhz band and tried to capture some ppm data from a 35.11mhz Hitec Optic 6 remote and the results were great:

I decided to direct the fm decoded signal from sdrsharp via VB-Cable into smartpropoplus to check if it can be decoded and it worked.

The next time i used a raspberry pi to receive the signal and direct it via rtl_fm and aplay into a soundcard input the same way the remote would be connected with a trainer cable.

The latency is pretty high because of rtl-sdr but this method works great with any remote control and it is not longer limited by a trainer port and you get some pretty good range.

It makes no difference in the delay if rtl_fm or sdrsharp is used but  rtl_fm is of course better for any „real“ use.

Just setting up this blog.

More stuff is coming soon.