Hi,
My friend and I just recently purchased a couple of OX2, and we were planning to use them for a sumo robot application. Ideally we would like to power the motors at 14V upwards but the board’s regulator will heat up dramatically due to the voltage difference. Is there any way to isolate motors power source from the processors power source?
Thanks.
Also when we received our package, were we meant to receive some capacitors for the VNH2SP30’s?
I’ve been dealing with that same problem recently, and I was able to separate the motor power source from the processor power source. I had to power the board with 12V because that’s what my motors need, but the board heats up dramatically and begins working improperly. I found that you can connect an better external 5V regulator to the sensor 5V bus next to the IO pins (I’m assuming that the solder jumpers on the back have been soldered to 5V). It bypasses the power switch and turns the board on (so you’ll have to have a separate power switch) and the motors can be powered by your larger 14V. Make sure that the power button on the OX2 is off, otherwise the onboard regulator will start burning off the higher motor voltage down to 5V and heat up, just use the external 5V power supply to turn it on and off. I don’t know if it is recommended to power the board this way, but I’ve checked many of the board functions and the board seems to have full functionality being powered up this way.
I received capacitors with mine. Actually everything was already soldered up for me (including the sensor power bus).
Hope this helps.
Hello.
It’s not necessarily a bad thing for the voltage regulator to heat up. It can reach temperatures well above what is comfortable for a person to touch and still function properly. It should be able to power the on-board components from a voltage supply as high as 16V without overheating, but given a VIN so much higher than 5V, you will probably need to use a separate supply for any external components you want to add to your project.
I don’t recommend that you power the on-board components with a separate logic supply. Instead, I recommend that you desolder the SMT jumpers that route power to the middle column of the user I/O banks and provide your own power from an alternate source to these banks for your external components. You can also significantly decrease your regulator’s power output (and hence its dissipation) by disabling the LCD’s backlight, or by powering the LCD backlight from a separate supply. Lastly, you might also consider adding a heat sink to the regulator.
Your Orangutan X2 should have come with capacitors already soldered into the motor driver board. Was this not the case?
- Ben
Thanks for the replies,
We both did not receive any capacitors soldiered on our motor controller chips. I thought it was a bit weird because when I received the motor controller by itself last year (separate purchase), they had the capacitors in the bag.
I will probably make a separate 5V regulator and run it off the 14.4V, it will be okay to feed the 5V into the logic on the OX2 right?
Alan
I apologize for our not including capacitors with your X2s. If you PM me your address, we will send you capacitors for both controllers.
As I said in my previous post, we don’t recommend using an external regulator to power the on-board logic, but it seems to have worked for other people.
- Ben
Hi,
My friend ordered the components so I will get his address and send it to you. Thanks for that. Also with the 5V external regulator I was planning to use, it was going to power external components but feed the result back into the board, just wondering if that was okay before I went about it. The onboard regulator will only power the internal logic and the LCD without the backlight. I think this way, I can limit the current going through the internal regulator.
Alan
It’s fine to connect devices powered from an external source to your X2 as long as their output voltages are within spec for the mega644 (i.e. between -0.5 and 5.5V). Just make sure your separate power source shares a common ground with the X2. If you connect your external regulator to the X2’s middle (power) I/O column (which give you an easy way to connect devices to it), you should desolder the power-selection SMT-jumper for that power bank on the underside of the board so that voltage doesn’t get shorted to the X2’s VCC line. Does this make sense?
- Ben
Thanks very much for your help.
Alan
