Hi There,
Today the ‘Pololu g2 high power motor driver 18v17’ came in and I directly want to starting up with it.
I connected the drive as follows:
• 12V over GND-VIN
• Out A en B connected on both poles of a 12V DC motor
• DIR, PWM en SLP at the left side connected to a 5v continue power supply.
I was expecting that the motor starting to rotate. But nothing is gona happen.
What am I doing wrong?
Regards,
Wouter
Hello, Wouter.
I am sorry you are having trouble controlling your motor. Can you tell me more about your setup? What is your 12V supply? How much current can it provide? Can you link to the product page or datasheet for the motor you are trying to control? Can you also post pictures that clearly show your connections and any soldered joints?
By the way, in your email to us, you asked about whether or not it is reasonable to connect a steady 5V to the PWM pin. That is definitely fine; it is the same as supplying a PWM signal with 100% duty cycle.
-Jon
Thank you very much of your reply Johnathan,
The supply is from a 12V battery charger which I already changed for an other example to make sure that this is not the problem.
The DC motor which is connected is from a 12V electric drill machine. It takes about 2,7A to start running and it wil continue rotating at 2A. Unfortunately I don’t have any specs of it, but I find out with a adjustable power supply.
I connected this supply to the GRD, DIR, PWM and SLP for the logical inputs with a voltage level of 3,3V and later 5V. (with a maximum current of 5A)
Even if I measure voltage at the disconnected wires of the DC motor, it doesn’t give any output at all.
A add some photo’s, so you can check the soldering or hopefully you can find some other misunderstandings.
Regards, Wouter
Thanks for uploading pictures. I didn’t notice anything wrong with your soldering, though making multiple connections with a single alligator clip like that might be suspect. Can you check all of your logic connections with a multimeter to see if they are measuring what you expect? (For example, if you measure the voltage at the PWM pin, it should read 3.3V.) If those measure what you expect, can you remove the connections to your motor and measure the voltage at the motor outputs and across VIN and GND?
Additionally, it sounds like you might have changed your motor power supply. What kind of supply are you using and are you still supplying 12V?
-Jon
Dear Jon,
I just checked the logical inputs with a multimeter. The 3,3V supply was directly give 0,0V when I connect as shown on the pictures. According the multimeter I see that there is a direct connection between GND-PWM and GND-PWM. I think that this is never gona work…
Any suggestions?? There must be a short cut some were on the board, I assume.
About the power supply, yes I changed the 12V powersupply for an other 12V supply. Both can give only this voltage.
best Regards, Wouter
Can you completely remove your motor driver from your setup and use the continuity function of your multimeter to see if PWM and GND are shorted together? If they are, then you might try closely inspecting the region of your connections around PWM and GND to see if there is something like a solder bridge or if the exposed metal parts of your wires are somehow touching. If there is no visible connection, it might be that your board is damaged.
If that is the case and you email us your salesorder information and reference this thread, I can look into helping you out.
-Jon
Dear Jon,
I was thinking at the same way as you. Maybe there is a bridge by some lose wires or a small piece or the soldering tin. But I took the magnifier to find anything that might be suspect. The board is looking fine from the outside and I’m 100% sure that it get no overload or something like that.
When I noticed that there is some connection between the logical inputs and GND the board was already disconnected from my setup.
I always put the 12V and 3,3V supply on before connecting to make sure that there is no peak voltage on the board or something like that.
I’m totaly outplayed of this issue. The board is now here for a week and I send will send you the salesorder.
Thank you for the coorperation and I’m awaiting for your response.
Best regards,
Wouter
