1 Overview 

SiRad Easy® r4 evaluation kits are experimental showcase systems for Silicon Radar’s integrated IQ transceivers, with antennas in chip / package and on board. The systems measures distance and velocity using FMCW or CW radar principles (frequency modulated continuous wave or continuous wave principles).

SiRad Easy® r4 consists of an evaluation baseband board that can hold exchangeable radar front ends (24 GHz to 300 GHz), all stackable as shown in Figure 1 (left).

2 Requirements

Minimum:

• Microsoft Windows 10 (supported) OR Microsoft Windows 7 (not supported anymore)

• 1 GB free HDD / SSD space

• micro USB to type A cable

• FTDI Chip USB driver (VCP) [1]

Recommended:

• active USB hub with at least 1000mA output current - some radar front ends need more power than provided by USB ports(!)

• 8 GB RAM or more

3 Installing Drivers and Tools on the PC

3.1 FTDI Chip USB driver

In order to communicate with the SiRad Easy® r4 via the micro USB, a virtual COM port driver is required. You may download the driver from the FTDI VCP Drivers page.

3.2 STM32CubeProgrammer (Optional)

If you need to re-program the evaluation kit with a new version of the firmware binary, then you will need to install the STM32CubeProgrammer software tool.

3.3 Realterm (Optional)

Realterm V2.0.0.70 is only required if you want to check the UART communication channel manually outside of the SiRad Gui application. The UART communication protocol requires <CRLF> line ending to be sent, and Realterm allows line endings to be configured to do this. 

4 Hardware Setup

The SiRad Easy® r4 evaluation kit consists of the following types of boards:

Type	Image	Description
Base		Contains the microcontroller and the micro-USB socket that is used for delivering power and for communication with the PC.
Front-end		There are different front-end boards, each with a different radar chip for evaluation. Shown here on the left is the TRA-120-002 Radar Front-End board as an example.
Breakout		This is an optional board that adds some buttons along with easy access to different signals from the baseband board.

4.1 Assembling the boards

The SiRad Easy® r4 boards are designed to be stacked on top of one another as shown in Figure 2 above. The board to board connectors are placed on the base board specifically so that only the front-end board can be connected on top side, and only the breakout board can be connected on the bottom side of the base board.

To connect the radar front-end board, place the front-end board centered onto the connectors, then press it down until no space is left.

4.2 Disassembling the boards

Disconnect the power from the Evaluation Kit.

Remove the radar front end from the top of the base board. Press thumbs and index fingers under the edges of the radar front end board and pull and press it simultaneously straight out of its connections.

Do not tilt or bend the front end board.

4.3 Powering the boards

The SiRad Easy® r4 boards can be powered via any one of the following ways.

1. Micro-USB
   The base board has a micro-USB socket which can be used to supply power to the boards, as well as communicating with the host computer. It is highly recommended that an active USB hub with at least 1000mA output current is used. Some radar front ends need more power than provided by USB ports.

2. UART Data Connection & External Power (External UART Header)
   The base board also has an UART header that provides an alternative way to power and connect to the board using a second UART port. The Base Board can be powered from the 5V and GND lines of the port. The UART header can also be used to trigger measurements manually via the trigger line (TI), or receive triggers on each ramp start (TO).

3. Data Connection & External Power (Breakout Board)
   The optional Breakout Board can be used to connect to different lines from standard pin headers, otherwise only available on the small connectors of the Base Board. The Base Board can be also powered from the Breakout Board’s BV5 and GND lines.

4.4 Upon power-up

By default, the base board is shipped with a firmware pre-programmed on it. Upon power-up, you should see the LED on front-end board start to blink. If not, please refer to the #Troubleshooting section below.

5 SiRad GUI

The SiRad GUI application provides a graphical interface to display the output data from the evaluation kit.

To download the application and the user guide, you will need to login to the Download area:

• SiRad GUI Application (FMCW – Graphical User Interface)

• SiRad GUI User Guide

Note that SiRad GUI requires the following firmware version and firmware output baudrate to be running on the board:

Start the SiRad GUI application and you will be presented with the Start Settings dialog box. Select the Serial Port COM port, leave the Start Settings as Default Settings, and then set the Kit Selectionto SiRad Easy® r4 as shown in the image below.

The main SiRad GUI window will then launch after clicking OK on the Start Settings dialog box.

Now, click on the Start icon in the toolbar and SiRad Easy® r4 will start streaming data to the SiRad GUI. The screen capture below shows SiRad GUI displaying the visualization of the data from the evaluation kit.

At this point, SiRad GUI have opened the Serial Port to the SiRad Easy® r4, and queried it for information. Click on the Parameters icon at the top right of the window, next to the RFE field. In the Parameters view, click on System Info to expand the section. Here you can view the information that has been queried from SiRad Easy® r4 kit via the Serial Port. For example, the RFE information, and the firmware version number, as well as the communication protocol version.

Close the Parameters view by clicking on the Parameters icon again.

6 System & Protocol Description

In the Download area (login required), you will find the System & Protocol Description document. This document describes the measurement flow and the command and data communication protocol.

7 Firmware Update

Using the STM32CubeProgrammer, there are two ways to update the firmware, either using the UART or the ST-LINK debugger. 

7.1 via UART

This method requires that the base board is running in the bootloader mode in order for the STM32CubeProgrammer to update the firmware via the UART. 

To enter bootloader mode, with the base board mounted on top of the breakout board, press and release the buttons on the breakout board in the following sequence:

1. Press BOOT button and hold

2. Press RESET button

3. Release RESET button

4. Release BOOT button

The firmware can be flashed after the device has been set to programming mode. 

In the STM32CubeProgrammer, select UART as the connection method with the following UART settings:

Switch to the Open file tab and chose the firmware file you want to flash. Then click the Download button to flash the firmware to the device. It should take some minutes. The flash progress can be observed with the green progress bar in the bottom of the tool. Just close the tool after the finished flash progress.

7.2 via ST-LINK

If you have a ST-LINK debugging and programming probe, like the STLINK-V3MINI (obsolete) or the STLINK-V3MINIE, you may choose this method to update the firmware in the STM32CubeProgrammer.

8 References & Documents

8.1 User Guides

1. SiRad Easy® r4, SiRad Easy® & SiRad Simple® User Guide

2. SiRad GUI User Guide

3. System & Protocol Description (login required)

8.2 Product Sheets

1. Product Information: StarterKit SiRad Easy® r4

2. SiRad Easy® r4 Base Board

3. SiRad Easy® r4 Breakout Board

4. SiRad Easy® r4 Boards & Accessories

5. SiRad Easy® r4 Radar Front End (RFE) Board TRXˍ120ˍ001

6. SiRad Easy® r4 Radar Front End (RFE) Board TRAˍ120ˍ002

7. SiRad Easy® r4 Radar Front End (RFE) Board TRXˍ024ˍ046

8. SiRad Easy® r4 Radar Front End (RFE) Board TRX_120_067

9. SiRad Easy® r4 Radar Front End (RFE) Board TRA_0120_045

10. SiRad Easy® r4 Radar Front End (RFE) Board TRA_300_042

8.3 Schematics

1. Schematics: login required

8.4 Datasheets

1. TRA_120_002 SiRad front end datasheet

2. TRX_120_001 SiRad front end datasheet

3. TRX_024_046 SiRad front end datasheet

4. Collimator Lens

5. Acrylic Lens

9 Troubleshooting

9.1 SiRad GUI

1. If an error message "cannot read line" is shown after hitting the "Play" button, check the following:

1. LED light on the front-end board is flashing. This indicates that the board is powered, and that the firmware is running.

2. Make sure the firmware meets the firmware version and output baudrate requirement.

9.2 Firmware Update

1. If STM32CubeProgrammer does not want to connect to the device, please check that the port is closed by any other programs.

2. If STM32CubeProgrammer does not want to flash, please check the baud rate setting as described above.

3.