Arduino control of SMC-2 doesn't start

I am new to Arduino programming, but I have a simple task. I just want my motor to start spinning in one direction for 5 seconds, then reverse, then repeat forever. I connected the SMC-2 to a laptop USB, and using its GUI, I can use the slider to move the motor. I then uploaded my Arduino with the sample advanced code in Section 8.4. I verified the connections for the 4pins and ground. I changed the example code for 5000 delay at the end, and changed the baud rate to 9600.
When I plugged the Arduino to the SMC-2 and removed the SMC-2 from the USB port, the red LED lights up and the yellow LED flashes 1/sec.
I had supposed that as soon as the Arduino code was uploaded, it would immediately start running the SMC-2 and the motor would start turning. In my final application, I don’t want to use a laptop, just the Arduino and the SMC-2.
Am I forgetting something, or will this simple combination not work? I appreciate any advice to get started.

Small addendum. I added Arduino code to turn on the LED on Pin13 when the motor is supposed to go forward, and off when the motor is reversed. That part is working, and verifies that I successfully uploaded the code to the Arduino. The SMC-2 still shows a red LED error.

Hello, Don,

Do you receive any feedback from the serial monitor from the Arduinio? Can you post some pictures of your setup?


Hi. Photo doesn’t show much, and I don’t see how to post a jpeg. I verified the connections, pin-by-pin. The Arduino is actually a RedBoard, equivalent to an Arduino Uno, if I understand correctly. I did purchase the Arduino Mega 2560 from Pololu, but that seemed overkill, so I am trying the Uno I had used for a different project. Should I try the Mega?

The Arduino only receives programming from the Arduino IDE through the USB. Can you tell me how to get feedback? All I have information on is the LEDs on the SMC-2.

Hi, Don.

To upload a picture to the forum, click the upload button (the flat bar with an arrow coming out of it) then choose a image you want to upload from your computer.

I don’t know much about Redboard, but I think the Uno would be sufficient enough for this. In order to get feedback from the Arduino, open the serial monitor using the tools tab->serial monitor. The Arduino must be connected via USB in order for feedback to occur. I have included a link to a helpful video on using the serial monitor.


Everything is working now; the motor is running alternately forward and reverse, with the Arduino powered by a 5V cord. I was able to make the Redboard (Uno) and the Arduino MEGA work with the simple or advanced examples.

I did ply with the SMC2 gui. Apparently, when disconnected, it remembers the status of all the options. The one think I did to make it all work was change the INPUT from ASCII to Binary. I can use auto-detect baud rate, disable safe start, ignore ERR line high, and it still all works. I am not exactly sure if changing the ASCII/Binary control was the key item, but it all works.

Thank you for replying, I might need your help in the future!
Dr. Bruns