uSplit Documentation

 uSplit Project Documentation

Here you can find information on every aspect of the uSplit; the UART port splitter for VESC based motor controllers

Disclaimer: I do not condone the use of UART based remotes operating in UART only mode with the uSplit. Only remotes with sending throttle through PPM and reading data via UART should be used with the uSplit. No control functions or safety functions should be performed through the uSplit communication ports. 

ESC FW Updates should also not be performed through the uSplit. This could brick the ESC and require it to be reflashed through JTAG.

Setup

To setup your uSplit follow these steps:

  1. Make sure your ESC is configured to use UART and the baud rate is set to 9600, 19200, 38400, 57600, or 115200 bps
  2. Make sure power to the system is off
  3. Connect the uSplit to the ESC by plugging the provided cable into the ESC port of the uSplit, then into the comm port of the ESC
  4. Connect any UART based add-on device you’d like into the DEV1-3 ports of the uSplit (As of FW v0.4, the uSplit will automatically detect the rx/tx pins of the connected devices) 

Updating the Firmware

The USB port on the uSplit is provided to allow the user to update it’s firmware when new versions are made available. Follow the instructions below to update the uSplit to the latest firmware. Before starting make sure you have downloaded the BOSSA or SAM-BA 2.15 tool and the latest uSplit FW from here.

  1. Make sure the uSplit is powered off
  2. Connect USB cable between uSplit and PC (The USB cable is used for data only, it does not power the uSplit)
  3. Hold “Flash” button (HW v1.0 only, v1.1 and on do not have a button) on uSplit and power it on (the module does not get power from USB so external power is required). The PC should recognize the connected device. Release button after this happens (Should be almost instant).
Using BOSSA

    1. Run BOSSA the flash programming utility
    2. Select the comm port that the uSplit is connected to
    3. Open latest .bin file (contained in the zip folder on the uSplit downloads page)
    4. Set the write options to “Erase all”
    5. Set the Flash Offset field to “0x2000” (this number needs to be exact or else the uSplit may become bricked)
    6. Press “Send File”
    7. If no error, close BOSSA
    8. Disconnect USB cable from both devices
    9. Restart the uSplit by removing power and applying it again. Since the uSplit does not get power from the USB cable, you will need to power cycle the ESC it is connected to.
    10. test out any new features
Using SAM-BA Tool

  1. Run SAM-BA Monitor 2.15
  2. Select the comm port that the uSplit is connected to (should be automatic)
  3. Select the “samd21_xplained_pro” board

  1. Change address under Flash tab to “0x02000”
  2. Open latest .bin file in the “Send File Name” field
  3. Set script to “Erase application area” and click “Execute”
  4. Press “Send File”
  5. If no error, close SAM-BA 2.15
  6. Disconnect USB cable from both devices
  7. Restart the uSplit by removing power and applying it again.  Since the uSplit does not get power from the USB cable, you will need to power cycle the ESC it is connected to.
  8. test out any new features

Troubleshooting

– Status LED always on (fast blink)

* This indicates the uSplit cannot communicate with the ESC
* Make sure the baud is set to 9600, 38400, 57600, or 115200 in the ESC settings
* Check the cable’s connection between the uSplit and ESC

– Dev or ESC LED alaways on

* This indicates that the uSplit is in an invalid state
* If issue persists report it along with details about the devices used to, support@solidcircuits.net