CentSDR (15): CW and FM are received.

The CentSDR is receiving CW signal on 40m band (7MHz) and the filter bandwidth is 300Hz. Filter is good but when the strong signal is received in the receiving bandwidth, the AGC suppresses the target signal.



FM Tokyo (80MHz) is received. Since the FM signal is strong, the audio quality is good.

CentSDR (14): It works!

After several fixes were applied to the board, it now works.

The attached picture is the CentSDR.

CentSDR functions will be evaluated.

CentSDR (13) : USB connector had to be fixed

The USB on CentSDR was detached from the board since the connection is only both sides of the USB connector and also the bottom of the connector. The manual describes the method to connect USB on the board, but the soldering connection was not enough.
The USB soldering on CentSDR was fixed with multiple soldering on the bottom.
It was most difficult part of the soldering work for the CentSDR construction.

CentSDR (12) : STM32 Virtual COM Port Driver and Putty

The CentSDR has USB connection which supports the serial interface. The interface accepts the set of commands for CentSDR.

Windows7 64 bits has installed the driver for the serial interface with the following link (STM32 Virtual COM Port Driver).

STM32 Virtual COM Port Driver
http://www.st.com/ja/development-tools/stsw-stm32102.html

After the COM port (serial interface) is enabled, putty is installed to get access to CentSDR. The speed of the serial communication is 56700 bps.

Putty
https://www.putty.org/


There are several commands when "help" command is issued.
The channel memory is set with "channel save NN". It also needs to issue "save" command to store it into flash memory.


Anyway, there is a python code to support CentSDR in the github, but it seems to be Mac. It should be updated to support Windows7.
https://github.com/ttrftech/CentSDR/tree/v0.6/python

CentSDR (11) : STM ST-LINK Utility and firmware.

ST-LINK V2 requires STM ST-ILNK utility (software) to write the firmware. It can be downloaded from st.com (STSW-LINK004).

The firmware can be download on this site. The file "centsdr-20180304.zip" has been downloaded as the latest one. It includes CW filter (300Hz) and red font is enabled for highlight.

Once CentSDR board is ready, ST-LINK V2 is connected to CentSDR board.
Here is the board connection as it describes in the construction manual :

• 2:TCK - SWCLK/JTCK
• 3:GND - GND
• 4:TMS - SWDIO/JSTM

CentSDR (10): ST-LINK V2

ST-LINK V2 has bee purchased to write the firmware into CentSDR. The attached picture is the equivalent with ST-LINK V2.