I assembled my shiny brand new autonomous DFRobotShop V2 without any sensor for the time being. I uploaded the sketch #1 with the only difference that I added a few lines to have led 13 blink. I did this because well the motors are not working.
When I plug in the USB cable to the rover from my lap top, the led 13 starts to blink normally as expected.
Question 1: Are the motors supposed to start spinning right away too or does the switch need to be in the ON position. In either case, nothing happens.
If I unplug the USB cable and plug in the LiPO battery and ensure the LiPO jumper is in place, the motors may spin for half a second when turning switch on then everything goes to a stop. Or only one motor will spin for a fraction of a second. The led 13 is not blinking.
In the FAQ, as you noticed my subject is a copy and paste of the FAQ , I let the battery charge overnight with my Samsung S4 battery charger but even before I put the battery on the charge, it was showing 3.9V. Not sure what is meant by default code in the FAQ.
Looking forward to make this working so I can add sensors
Please contact us via the support center (exchanges returns department) and we’ll see if the board is still under warranty. Note that it’s unwise to plug in all three power sources at the same time (USB, barrel and JST).
How are you powering the motors? You should be using either a 3.7V LiPo battery or the 4xAA pack (and be sure to remove the jumper at the left rear of the board). The On/Off switch needs to be set to On. Use the sample code under “troubleshooting” in the guide to do a “full speed test” to ensure the motors are connected properly. You are aware that the DFRobotShop Rover PCB has a built-in LiPo charger specifically for that LiPo battery? You only need to plug it into a USB port.
Unfortunately not. We can certainly include a note in the manual for the next revision.
Most computer USB ports can only provide about 400mA, while the motors require about 250mA each, and the board itself needs at least 100mA - this means it would try to draw more current than the USB can provide and might fry that USB port.
Sure, though the USB would be powering the Arduino while the battery would be powering the motors.
So to confirm, you connected the motors to the screw terminals, and the charged LiPo to the JST connector, uploaded the sample “full speed test” code (and set the board to “on”) and the motors don’t turn at all? If you can include an image of the setup it would be appreciated, but it sounds like it might be a defective board.
I will look into this. Don’t worry, at all time there was only one power source plugged in (LiPo ins that instance) with or without USB as per post #4 which you confirmed was ok. That’s why I asked, I was unclear about this. Thanks.
Well there has been some development. It seemed things were doing better until I connect the board back in the computer. Now the board is no longer detected and the Atmega chip gets rather hot. This is what I did.
No USB plugged in, no LiPo, no LiPo jumper, I plugged in a 12V wall warts in the barrell connector. Nice surprise, motors spins like crazy. I turn switch off right away. I removed the tracks, so I can put the rover on a table without it running away, remove the wall wart plug, put the LIPo jumper an battery. Now its spinning. But the led 13 that should normally flashes stays on… NOw I plugged in the board in the laptop through the USB cable, no connection. And the main chip gets hot. Is that thing toasted now? My other arduino uno board is detected fine BTW.
As I said, I power the motors with the LiPo battery which showed 3.9V on the DM. I am aware that there is a built in charger but nowhere in the documentation nor in the forum I found a place that indicate if that built in charger has a state charge indicator. From what I saw on the forum, I am not the first one to wonder about this. Maybe this should be documented somewhere.
That is exactly what I did, with the addition of the Led 13 when I saw things did not work as expected.
Yes, but if the board is not powering the motors, maybe it is not charging the battery neither…
Also, maybe I poorly formulated my question 1, but can the motors be powered simply through the USB cable? I know one would not do that in normal operation but for programming purposes that would be convenient. Or can both the USB cable and batteries be present at the same time?
Yes that would be very nice I beleive. Not That I want to go off topic, but an HTML version of manuals would be nice. food for thought.
Ok, that helps. Thanks.
Perfect.
I shall try again tonight and take pictures as well, no problem. If I recall correctly, I measured the voltage at the screw terminals and it was nil. l also measured voltage at the pins 5 and 6 and there was voltage. Actually, I also tried with digitalWrite(M1,200) and digitalWrite(M1,255) and voltage was different which I guess makes sense.
I installed Arduino as per my Linux distribution (Slackware). Or maybe even from source, I forgot. Is it possible I am missing something? Is there an additional specific driver required? Sketeches upload without problem so I would say all is ok.
, I let the battery charge overnight with my Samsung S4 battery charger but even before I put the battery on the charge, it was showing 3.9V. Not sure what is meant by default code in the FAQ.