Using Grove Motor Driver with EmakeFun BLE nano MCU

Products & Technology Grove
#1

I have the Emakefun BLE nano MCU, which is allegedly completely compatible with all Arduino sketches with no changes in pin assignments. I am trying to use it with the Grove I2C motor driver (TB6612FNG) board to drive a biphase stepper motor. I do NOT have the GROVE shield that would allow me otherwise to employ the proprietary GROVE I2c connector, but according to the EmakerFun manual here is the pin assignments on the Arduino that correspond to the colored wires on the I2C Grove connector:

Arduino Pin and I2C Connector Wire color
8 ------------- yellow (SCL)
9 -------------- White (SDA)
10 ------------- Red (VCC)
11 -------------- Black (GND)

Can someone here please confirm these pin assignments as being correct for the Grove I2C connector? I ask because here’s my present status:

  1. I have used the Arduino Stepper Motor One Revolution sketch, uploaded it successfully to the BLE nano MCU and without yet connecting the Grove driver board, I placed LEDs (with a 220 ohm series resistor) at MCU output pins 8-11 connected then to ground.

  2. I powered up the MCU and the LEDs flash rapidly as I expected they should for a stepper motor drive.

  3. Using a separate power supply connected to the Vm and Grnd Grove driver terminals and the above I2C connections to the MCU (see the above table), when I power up both the MCU and the driver board the motor does not turn and I even tried using LEDs connected to ground at the Grove driver OUTPUT terminals and no motor connected to see if there’s any output; NONE.

  4. My suspicion is that the wiring assignment provided by emakefun is wrong. I don’t want to experiment trial-and-error with the I2C connection assignments but this seems like the only possible source of a problem.

5, As a side note, with nothing but the Grove driver board connected to the MCU, I noticed that my LED’s used to sample the outputs of pins 8-11 on the MCU board get reduced in brightness by about 50% as soon as I connect the Grove board using the I2C pin assignment listed above. So there’s definitely a load being experienced by the MCU with that pinout connection by just connecting the Grove driver with no other connections to the Grove driver.

#2

Emakefun BLE nano MCU ? what’s that ?

#3

The Emakefun BLE nano 3.3 is a tiny microprocessor contol unit (MCU) that has onboard both wifi and bluetooth communication hardware. Its about the size of my thumb. While it’s supposed to be completely compatible with Arduino software and pinouts (which so far I have found to be true), its ability to interface with the Grove I2C stepper motor driver board described in my post is still a challenge for me…

Here is an Amazon link to the Emakerfun item. I have the manual in pdf form, but I’m not sure yet if or how to upload it here.

https://www.amazon.com/Emakefun-Wireless-Bluetooth-Micro-USB-Interface/dp/B07QM6KHS4/ref=sr_1_14?crid=2B4F6OR2FAEAJ&dchild=1&keywords=arduino+nano+33+ble+sense&qid=1594784089&sprefix=arduino+nano+33%2Caps%2C219&sr=8-14

#4

We are not familiar with this, if the I2C hardware is properly connected, and the data is sent and received correctly.It works.