Using Your Spectrum's Micro-USB Port For Dragonframe and API Communication

When the Spectrum ST4 was released back in 2016, it shipped equipped with an i/o port that enabled user to connect their Spectrum to their computer to chat with eMotimo’s API. This function is commonly utilized in conjunction with Dragonframe. The only way to connect the i/o port on your Spectrum to the USB port on your computer, was a delicate, and proprietary cable that could only be purchased through eMotimo. We evolved with our code and firmware and support a regular USB cable for serial communication.  

Those limitations are now yesterday’s problem. With the latest firmware (RC008), we’ve “turned on” your micro-USB port which can now serve as your new API communication port. No more expensive, delicate, and proprietary cables. Just an inexpensive, robust, non-proprietary micro-USB to USB cables.  

“So, can I just plug it in and go?” Not exactly. There are a few things worth mentioning before you jump on in. Read through the following “How To” section below and pay close attention to the WARNING.

We’ve opened up this functionality to all users.  Please plan on reporting any bugs to help@emotimo.com.  

Start this process with your Spectrum powered ON. This is vital. Yes, your spectrum will “turn on” when you “power it” via micro-USB however, the motors will not initialize properly and will ultimately leave the Spectrum in a state that is both ineffective and glitchy. Do NOT attempt to continue in this state.

Here are the steps:

1. Power up your Spectrum with either an approved 12v/24v power supply battery or a known good battery. Once the Spectrum has booted up normally, you can now connect your micro-USB cable to both your computer and your Spectrum
2. Navigate to your “Settings” tab
3. Navigate down to “USBPort: Off” (Page 5 of 7)
4. Toggle that menu option to “eMotimo API”
5. Your computer should now recognize your Spectrum

Let’s move on to a few brief tests to verify that we have an effective connection. For this test, you will need a terminal program. We won’t make any official recommendations here but there are many good options available online.

1. Review your terminal settings and verify that the serial port recognizes “USB Serial Device”
2. In order to ensure that your settings are correct, take a look at the API DOCUMENTATION HERE.
3. Send a status command. A good example command is “G500”. When sending the Spectrum a “G500” command, you should get back a “000 0,0,0,0” message. This is expected because we have not yet moved the unit. It’s real position is currently 0.
4. Now send a “G1” command. This essentially tells the Spectrum, “Move the motor here”. Feel free to copy and past the following move: G1 X50000 Y70000 T5.0 R1.0
5. 5 seconds after sending the command, you should see your Spectrum arrive at the commanded destination. (ie the commanded Pan movement, the commanded Tilt movement, over the requested 5 seconds, with a Ramp of 1)

Next, let’s chat about connecting to Dragonframe.

1. Power up your Spectrum with either an approved 12v/24v power supply battery or a known good battery. Once the Spectrum has booted up normally, you can now connect your micro-USB cable to both your computer and your Spectrum
2. Navigate to your “Settings” tab
3. Navigate down to “USBPort: Off” (Page 5 of 7) – This may also show “eMotimo API” if you’ve just completed the test above.
4. Toggle that menu option to “Dragonframe4.1+”
5. Open the Dragonframe program.
6. Head over to the “Scene Settings” menu and select “Connections”. Select “eMotimo Spectrum ST4”, then “ArcMoco #1”, then “USB Serial Device (COM6)”. Click the “Connect” button all the way to the right. Once connected, the “Connect” button should turn green and the “Status” should now read “Connected to eMotimo Spectrum ST4”.
7. On the Spectrum, navigate to the Telemetry screen and toggle to the Dragonframe Telemetry page.

There’s extensive documentation to direct you on how to get started using Dragonframe (click here for that document). We are going to continue this “How To” writeup, assuming you know how to use Dragonframe.

8. In Dragonframe, jog your motors to verify that your pan and tilt axis are live. You should be able to verify this both by the physical movement of your Spectrum AND the feedback data on the Dragonframe Telemetry page.
9. Set up a basic shot. Set a couple keyframes and give each axis some direction. Upload that move and press play. The Spectrum should jog back to the prerole frame then execute the move. If the Spectrum completed the move as expected. You can conclude that your Spectrum’s micro-USB port is functioning properly.