And I’ve copy and pasted the Arduino code called: “Sketch #1: Basic Rover – Full speed forward” from source 2 (above) into the Arduino IDE and the motors are not moving despite them being soldered up and the sketch being successfully uploaded to the Arduino.
Troubleshooting steps already taken:
I’ve used a picoscope to trace the voltage. The DFRobotShop Rover Sheild is powered as shown by the on-board LED, and the Ardunio is sending a Digital output through Pin 5 and Pin 6; which the shield is receiving although, the shield is not relaying any voltage to the motors and the voltage coming from the board to the M1 & M2 wire-junction is only 100mV (which I assume is not enough to drive the DC motors). The 3.7V lipo successfully charges and discharges fine.
@TSantini Welcome to the RobotShop Community. Since you have both the base and the shield, did you purchase this kit?
Can you provide a few clear photos of your setup to see if there’s anything we can spot?
If the battery is charged, the wires are connected to the screw terminals properly, and the code uploads without error… is the ON/OFF switch set correctly?
Although it might seem evident - are the wires properly inserted into the screw terminals?
Yes, that’s the exact kit that I was gifted. I’m attaching a whole bunch of photos - let me know if I’m doing something wrong. For my next troubleshooting, I’m going to fully charge the battery and see if it’s just that it needs to be at full charge to operate the motors.
The below photos were taken while the battery is being charged (using the MicroUSB) and the screenshots of the IDE are from when the data cable is plugged in and uploaded to the Arduino [Just clarifying that I know that the Arduino is connected through the data cable not the MicroUSB in the photos]
Nothing evidently wrong with your setup. If you had reversed the motor wires in the screw terminals one motor would go backwards while the other would move forwards (easily resolved by switching the wires). The code seems to upload correctly. The tracks seem to have been installed correctly (not too tight).
So let’s go with potential common errors:
During the gearbox assembly:
A common mistake is to put the set screw into the shaft collar in step 14.
If the set screw is in place, the shafts cannot turn. You can check to see if there’s something wrong with the gearbox assembly by gently removing the motors (so the gears don’t mesh) and running the code (free spinning).
Can you provide a few clear images of the connections to the motors? Did you solder the wire or use the included crimps?
Might as well turn the switch to OFF during charging (no point in draining the battery to run the MCU while charging).
I’ve fully checked the gearbox assembly and I have not made those mistakes (but thank you for letting me know). To help, here’s a quick video on the motors spinning successfully when I power it with a 3.3V supply.
Yes, I have directly soldered the connection because I thought it was the connection to the motors that were faulty.
I’ve checked again that the Ardunio is working properly through the default Blink codes and it is still working fine. I’m starting to think that the Ardunio shield is faulty because I don’t know what else to check
I can understand the rationale, but it’s best not to apply power to the screw terminals as it may backfeed power to the motor driver and burn something internally. Soldering the wires to the motor pins is best.
Can’t spot anything else which might be wrong. Since you have a second Arduino, can you try with that just in case? If that doesn’t work, it seems like the issue might be with the battery or motor shield and we’ll proceed with an RMA. Do you have a means to check the battery voltage? Normally these units are pretty reliable. Do you have an order number or email we can use to find the order? Since it was a gift, would the shipping address need to be changed?
That’s a good idea, I’ll switch out the Arduino and see if it makes a difference.
Okay I’ve just done that, and unfortunately, nothing has changed
To check the battery voltage - I have a picoscope. So I’ll follow up with photos/videos of that now.
Unfortunately, it was a leaving present from my previous work so I don’t have an order number and yes the shipping address would have to be changed to my current home address.
Here is the video of the picoscope recording the voltage coming from the battery and it seems to be discharging very slowly, although I think this is normal.
To confirm, you measured the battery voltage at ~1.5V?
It should be close to 4.2V when charged (it’s a 1S LiPo) and should not go below 3V.
If that’s the case, then it’s the battery which is the problem and is way too low. Not even sure many charging / discharging cycles will help bring it back up.
Oh, hm right so I’m going to try to find a way of testing if it’s the lipo battery so see if that’s the problem and I’ll get back to you. (here’s an image of the lipo in question)
You seem to know what you’re doing, so just be sure not to close the circuit (don’t have the positive terminal contact the negative terminal of the batter). It’s a pretty inexpensive battery, but the issue is shipping LiPo is not easy these days. If you find it’s depleted, we’ll see how we can get you a replacement.
Hi @cbenson!
I’m finally found the time to get back to it, and I’ve found that you were correct the Lipo is not able to hold a charge.
This first screenshot is the Lipo at what I can only assume is zero charge (i.e.fully discharged)
This first screenshot is the Lipo- at what I can only This 2nd screenshot is the voltage of the Lipo after 30mins of charging via micro-USB via the charging port.
I’ve given it a go and the robot works. Although the DC motors are only receiving 2V so they are somewhat slow and so don’t have much torque - is this correct?
Many thanks for all your help.
Hmm, so it looks like it might be salvageable or at least have some life left. Can you do several charge / discharge cycles where it drains down to around 3V? It might charge slightly higher each time. You are correct that at 2V, the motors can provide quite a bit less torque. If you see the rover really slowing down - time to recharge.
Time to add control from an IR remote? Looking forward to seeing what you do with future projects. If the LiPo ever becomes puffy - time to change it.
Thankyou @cbenson I will give that a shot. Haha yes! An IR Remote is the next step I’ve bought a controller already!
So as an update:
There ain’t no rest for the wicked and the problems continue. After some charge and drain cycles, it seems the battery is struggling with holding a charge and drains unusually quickly.
More importantly, when I take out the battery from the system and instead, wire-up a 3.3V supply to the shield (in-place for the battery) still, unfortunately, doesn’t move in the way it should. Although, when I wire up a 5V supply to the shield (in-place for the battery) it works perfectly; although I’m worried since the board is not rated for 5V I’ll burn something out.
