Showing posts from October, 2020


Yesterday I received the RX888 designed by Justin Peng and Howard Su.  The first impression in o pening the shipping package  is that it is very small.    It is as big as the Cypress fx3 superspeed explorer kit ! Thanks to Guy Atkins'  SWLing post  I was able to resist the desire to open it right away to see the interior.   I started looking at HF. I connected it to my old I7-3770 pc and to the 10 meters wire antenna that I have on the balcony of my house.   My city is Turin and here the local transmitter in MW has frequency 999000 Hz synchronized to a high precision reference. I tuned this station and without calibration of the internal oscillator of R888 I measured an accuracy better than 1 ppm. This is not obvious after a transport of more than 10000 Km. In case there is the internal trimmer that allows you to calibrate the reference oscillator when you have a reliable reference. Frequency calibration test The ExtIO_RX888.dll v0.4 has the gain scale calibrated without subtractin

HF103 - ARM firmware

The analog to digital converter (ADC) and the USB3.0 controller (FX3) are the main hardware components of HF103. HF103 block diagram The FX3 firmware sends the ADC output data stream to the USB3.0 host. Let's take a look inside the ADC and FX3 chip architecture. HF103_FX3 is the name of HF103 ARM firmware. This is a redraw from my previous BBRF103 FX3 code after a first reading of the book SuperSpeed Device Design ByExample John Hyde . I found it very useful in learning the FX3 software architecture and coding. I followed the book Project template, using the same name for files. Please refer to the book to have a far better description of the architecture. RunApplication.c is the application thread. USB_Handler.c manages USB traffic. USB_Descriptors.c defines the descriptors. StartStopApplication.c starts and stop application. DebugConsole.c is a debugging console. Support.c here are support procedures. Startup.c sets up the FX3 environment for the program. cyfxtx.c def