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MD30C project box

PostPosted: Fri Dec 15, 2017 2:51 am
by liteace
Hi All, Im new here, I hope ive posted in the correct section,
Ive just taken delivery of my MD30C controller board and have a few questions.

I want to mount the controller in a plastic project box, on the box I would like to put the switches, pot and led's, can someone please tell me:

What value pot do I need.

What are the best LED's to use and also what way to connect them to the board,
anode cathode, positive, negative.

Will the controller work OK with a 5 volt supply and drive a 5 volt motor

And last, Ive not tested yet, I assume the controller is ground side switched

Thanks



Thanks

Re: MD30C project box

PostPosted: Sat Dec 16, 2017 6:45 am
by ober
Generally, please do check the MD30C User's Manual
What value pot do I need.
In the User's Manual, we are using a 5KOhm potentiometer. So you can try with that as a start.

What are the best LED's to use and also what way to connect them to the board,
anode cathode, positive, negative.
Well, normal 3mm or 5mm LED should be good enough. Since MD30C does not come with extra pads for external LED, you have no choice to do some soldering and hacking work. As LED comes with polarity, the easiest way is to trial and error. Putting your LED parallel with the LED and try to power up the motor to activate, if it like up, solder it!

Will the controller work OK with a 5 volt supply and drive a 5 volt motor
Yup, 5V is the minimum operating voltage.

And last, Ive not tested yet, I assume the controller is ground side switched
Not really understand what is ground side switched, but the grounds are commoned, power and signal grounds are same

Re: MD30C project box

PostPosted: Sat Dec 16, 2017 7:30 am
by liteace
Ground side switch is when there's constant power, positive +, and the negative -, is switched with the pwm controlling the motor speed

Re: MD30C project box

PostPosted: Sun Jan 07, 2018 8:59 pm
by liteace
ober WROTE:Generally, please do check the MD30C User's Manual
What value pot do I need.
In the User's Manual, we are using a 5KOhm potentiometer. So you can try with that as a start.



Would using the 10K Ohm potentiometer give me more control ?

Re: MD30C project box

PostPosted: Mon Jan 08, 2018 5:31 am
by ober
liteace WROTE:Would using the 10K Ohm potentiometer give me more control ?

Just update, we have retest 5K external potentiometer, and it will generate quite some heat at certain speed, so please do use 10K ohm instead.

Re: MD30C project box

PostPosted: Sat Apr 07, 2018 11:14 pm
by Adrare
@moderator,
Hello,
in your repply you wrote that grounds are commoned; on the board MD30C R2 I just received, it seems (according to my ohmmeter) that there is a diode between the minus power pin and the Gnd pin of the ext PWM connector (JP6 being on ext position); the cathode seems to be on the power side, anode on the PWM connector side. So my questions are:
1/ how is the Gnd interconnection made, would you have a sketch of it ?
2/ I'd like to put a 0.05R resistor in order to measure the current in the motor and prevent from overload :idea: ; this resistor should be seen by an analog port of the MCU (PIC18F), referenced to ground. Where do you suggest I should place it in the power circuit ? I'm confused with this diode between the 2 Ground... :?
Thanks a lot in advance,
Gerard

Re: MD30C project box

PostPosted: Tue Apr 10, 2018 3:05 am
by ober
Adrare WROTE:@moderator,
Hello,
in your repply you wrote that grounds are commoned; on the board MD30C R2 I just received, it seems (according to my ohmmeter) that there is a diode between the minus power pin and the Gnd pin of the ext PWM connector (JP6 being on ext position); the cathode seems to be on the power side, anode on the PWM connector side. So my questions are:
1/ how is the Gnd interconnection made, would you have a sketch of it ?
2/ I'd like to put a 0.05R resistor in order to measure the current in the motor and prevent from overload :idea: ; this resistor should be seen by an analog port of the MCU (PIC18F), referenced to ground. Where do you suggest I should place it in the power circuit ? I'm confused with this diode between the 2 Ground... :?
Thanks a lot in advance,
Gerard

Hi Adrare,
The common ground is referring to:
- GND on JP3 which is the external PWM and DIR control pin.
- GND of power input (if the polarity is correct as there is polarity protection MOSFET on board)

The rest of interface including EXT POT (JP5) where an external potentiometer is connected are not common grounded.

With shunt resistor method and common ground is needed to measure from external microcontroller, you can put the resistor at the power terminal, negative terminal :
JP1 (POWER) Negative terminal ------ 0.05R resistor ------ Negative terminal of battery (Ground)
Where the microcontroller GND should be connected to Negative terminal of battery too.