Thanos AMC1.6 USB 2DOF Motion Controller

[tronicgr]

Hi Thanos thanks for your good work !! Its very helpfull.
I just wanted to say that it would be very cool if you could do a post about the moter drivers. Just put a quick comparaison of each solution.
Right now I am hesitant between building your Dual Mosfet H-Bridge by TronicGr or buying a drivers. What would a palulu drivers be do thatthe one you design or the chez dual one on ebay coulnt do ? I am using Wiper Motors !

I cannot advice you on what you need to use. I just present here the solutions that are available. It depends on the motor type and the power supply you want to use and most important on the budget you have. In the end you get what you pay for.

So in answering your question of what is the difference between Pololu 18v25 motor driver and the DBK-HT Dual motor driver:



I run out of space in my camera so here is what I would like to add:
Maybe its just the higher PWM frequency I use (21.6Khz) that causes this behavior, I have yet to try with 10-bit resolution (10.8Khz PWM) to see if there is difference. Or maybe something is not correct on the board as in the manual it says to be careful placing correct offset between the current sensor and the slew rate resistor. I have no way verifying this as I have no schematic of the board. Also in the manual it states that a 470nF ceramic capacitor from VS to GND close to each device is recommended to provide current for the switching phase via a low inductance path and therefore reducing noise and ground bounce. I believe this capacitor is missing. Apart from that if I place this capacitor externally on the motor leads It seems to make it work as it should, but in RC filtering mode.

All in all, its a cheap solution for use with car wiper motors for simple simulator cockpits.

Thanos

[tronicgr]

Hi Thanos,

Today a friend ask me for repair his H-bridge (DSMhb1_2b) but it is in a really bad state, so I decided give mine and start a new board.

I tell you that because I have seen that you are working on a new simple hbridge that I would like to test. Now, I think I have all parts to start the construction. Is ready for testing or better I make a new DSMhb1_2b board?

This h-bridge is not tested yet. I'm still waiting for the PCB's (thanks to Gilles from France).


Thanos

[Roadster2]

Hi Thanos. Don't know if it's just here but the last video stops at 57 seconds and wont continue. This is the same with three different web browsers.

[tronicgr]

Hi Thanos. Don't know if it's just here but the last video stops at 57 seconds and wont continue. This is the same with three different web browsers.

Its fine here. I'm using google chrome and just tested it on internet explorer. Maybe you need to update your flash player version...

[tronicgr]

Hi again,

Since I had my equipment ready I took another video of the HMD-02 motor driver. You can see clearly it jumps to full speed at certain PWM percentage and misfires on one direction at full speed, with or without filtering on the motor.



Thanos

[sirnoname]

Jumping to full speed looks like the input is detected as (low or) high and the PWM signal is not recognized.
May it help to add a 10kOhm pullup to all of the signal lines at the bridge?

[tronicgr]

This HMD-02 motor driver has already built in pull-ups on its PWM inputs. And pull-down on its direction inputs. This is no issue from signal noise. The AMC1.6 signal is crystal clear and the better build Pololu 18v25 proves it. And I know there is pull-up there because if I use only the direction inputs I get full speed on each direction (still in jumpy misfire motion on my servo motor).


Anyway, I give it a shot with less frequency PWM (at 10.8Khz) and seen no difference, so must be something wrong with my HMD-02 module.

See in the next video how it does with car wiper motor. This motor is un-modified so it must have filtering caps built-in.



Thanos

[tronicgr]

Today I received from Gilles (France) the two-layer boards of AMC1.6, Optolink and SMh-bridge2.2 I mentioned in older posts. I'll try to have them ready soon to test them all and try to make a little assembly guide for them as I do it. I hope I have enough parts left for all this.

AMC1.6 plus optolink plus SMh-bridge.jpg (1.03 MiB) Viewed 6931 times

Optolink plus SMh-bridge.jpg (988.22 KiB) Viewed 6931 times

The new AMC1.6 board is a little smaller, more compact connector for the PWM and directions, less wasted space.

AMC1.6 old vs new version board.jpg (857.09 KiB) Viewed 6931 times

I made the power tracks as large as I could for the SMhb2.2. See it next to the old DSMhb1.2. These thick tracks are rated 14A and even more if they get reinforced with extra solder.

SMh-bridge power tracks vs old DSMhb1.2 tracks.jpg (944.55 KiB) Viewed 6931 times

Thanos

[vicpopo]

Hi again,

Since I had my equipment ready I took another video of the HMD-02 motor driver.

Thanos

Hi Thanos,

I burned my 2 hmd-02 with my big worm motor!!
I will confirm to all x-simer that this simple h-bridge is not suitable for bigworm motors!!
I get no problem with wiper motors although you didn't validate it.
Happy that you've got the PCB.

Best Regards

[motiondave]

Well done on the pcb
Thats some groovy tracks there!