mBot Ranger Not Responding Over Bluetooth in mBlock or mBlock App

#1

Hi, I have recently acquired a mBot Ranger. The unit does not respond to commands over bluetooth in mBlock (3.4.11) or mBlock app. I have successfully connect the board via USB COM3, selected the mBot Ranger (Auriga) board, upgraded firmware and run a few sketches.
I have also successfully connected Ranger to computer over bluetooth but when I select upload to Arduino, mBlock reports the following messages:

vrdude: ser_open(): can’t open device “Makeblock”: The system cannot find the file specified.

avrdude: ser_drain(): read error: The handle is invalid.

In the mBlock app, I first reset default program then connect Ranger to ipad over bluetooth, run the sketch but nothing happens. I was for a while seeing a firmware not found or invlalid error, but haven’t seen that lately, but still connecting over bluetooth.
Note about the default program…from the first power up, the motors just ran with the line following sensor activated such that when on the ground, one servo would turn one direction and the other the opposite direction. When Ranger is lifted off ground, servos both rotate in same direction. This is the case whenever the board is set to the default program.
Windows10. I have also tried a macbook running Sierra but can’t even get the serial port to work on that.
Thank you for any help.

My mbot ranger does not work
#2

Hi Aike,

For the first problem about error occurs when you upload to arduino with Bluetooth module, actually this is normal since Bluetooth connection doesn’t support upload program to the mBot. For detailed explanation, please see this document.33. Why it fails when upload program to Makeblock robot wirelessly though 2.4G or Bluetooth.docx.zip (9.8 KB)

For the second problem that the robot doesn’t function when run the sketch on mBlock APP (on iPad), could you please take a picture for the sketch?

For the third issue that the motors rotate differently while put on ground but rotates okay when take it up, please kindly reset default program for it again refer to this instruction have a check.How to Reset default program for Ranger with mBlock 3.4.x.docx.zip (411.0 KB)
Please note: it is suggested to temporarily remove the Bluetooth module while resetting the default program.
If the robot still functions the same way, please change the battery for the robot since it will function abnormal if it can’t get enough power.
According to our test and research, it is suggested to use rechargeable Li-ion battery or rechargeable nickel-metal hydride, nickel-cadmium which can be bought from amazon or local shop. Or Alkaline battery with good quality like Energizer, DURACELL (but non-rechargeable battery can’t last long).

For the last problem that the Mac sierra can’t detect the Serial port, you need download and install the arduino driver for the Mac:
If it is Mac OS Sierra, you can install the Arduino driver refer to this document.
If it is Mac OS High Sierra, you need download the driver from this link and install it.

#3

Thank you for the speedy reply!
When I upload the sketch, “when up arrow key pressed–>run forward at speed 100” via USB, disconnect USB, power on, connect to bluetooth, hit up arrow…nothing happens. A small blue LED on main board under bluetooth module lights when up arrow is pressed as if the board is receiving signal but does nothing. Are “events” in mBlock software considered standalone operations? What else would be considered a standalone operation? And can standalone operations be successfully executed in a sketch with non-standalone operations?

See photo of ipad sketch.

IMG_2550
IMG_2550.jpg2016x1512 600 KB

Also here is a photo of the Auriga board.

IMG_2551
IMG_2551.jpg2016x1512 742 KB

I have removed bluetooth board to reset the default program, but the ranger behaves the same as both motors start immediately after the default program is reset. I am on the second set of new Duracell batteries…will try rechargeable.
I will try mac next…
update: I have installed the driver you recommended for High Sierra and I can now communicate to Ranger with Mac, however the issue remains that once I upload the sketch “when up arrow key pressed–>run forward at speed 100”, nothing happens.
Thanks again!

#4

Hi Aike,

The “events” in mBlock software is not considered standalone operations? It can be run with Bluetooth connection.
Please refer to the FAQ 6 in this post to distinguish the online mode and offline mode (standalone).

For the current issue, could you please try the following steps to run a online program via Bluetooth again:

  1. Upgrade firmware for Ranger with mBlock software with USB connection refer to this documentHow to Upgrade Firmware for Ranger with mBlock 3.4.x.docx.zip (358.5 KB)
    Please note: temporarily disconnect the Bluetooth to any device while upgrade firmware.

  2. Disconnect the USB cable, connect the Ranger to mBlock with Bluetooth.

  3. When the Bluetooth is connected, please run the following program and see if it works:
    image

  4. You can also temporarily remove the tracks from the wheels and test again.

If there is still no response from Ranger, please kindly test it again when you have the rechargeable lithium battery.

#5

Hi,
I installed a new set of Duracell batteries, upgraded firmware with usb, turned on mBot. As soon as it powered on, the tracks started moving, I lifted it (to not move), then connected to Bluetooth and ran the program you listed. The tracks kept rotating as when first powered on after firmware upgrade. The video shows just after power on.
https://drive.google.com/open?id=100VmkqQogdY-_fqmIShN-F8SF6Y0Alxz

#6

Hi,
I have tried new NiMH batteries and the problem persists. When the Ranger is powered on after firmware upgrade, the tracks begin to rotate, without running any sketches. Is this normal operation?

#7

Hi Aike,

The mBot Ranger may be not in the Bluetooth mode. Please set it to Bluetooth mode with mBlock software on computer have a check refer to following steps:

  1. Connect Ranger to computer.
  2. Select mBot Ranger (Auriga) under boards.
  3. Select the serial port for Ranger under the Connect->Serial port.
  4. Select the bluetooth mode under Connect->Set Firmware Mode
    image
  5. Then upgrade firmware for the Ranger under Connect and see if the Ranger still function abnormal.
#8