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Jan 4, 2021, 4:34:03 AMJan 4
to Radioberry
Hi All,

In the search,
of finding a higher IQ bandwith and a reduction of the CPU utilization for the radioberry,
hereby a proposal:

The radioberry with the high coupling to the RPI must be kept; i want to keep the charm of running a standalone radio.

I like to introduce a Radioberry FT2232H extension board.

This radioberry can be plugged in to the board (like you connect a RPI).

This board contains the FTDI FT2232 chip and implements an USB interface. 

The extensionboard communicates with any SBC/PC via USB, making it possible to connect better performing SBC or a PC.

To allow USB communications between a PC and the FPGA,
the extension board uses an FT2232H USB device to create a communications bridge between the PC USB interface and the FPGA. 

This communications bridge splits into two channels: a programming interface
channel and a parallel 245 FIFO communications interface channel. 

The programming interface uses channel B of the FT2232H to configure the FPGA using the Intell Cyclone Passive Serial interface. 

The 245 communications interface uses channel A of the FT2232H to transfer data, either synchronously or asynchronously, over the 245 FIFO interface to and from the FPGA. 

The extensionboard utilises the functionality of the Multi-Protocol Synchronous Serial Engine (MPSSE)
architecture in channel B of the FT2232H chip to adapt to the Intell Cyclone  Passive Serial interface. 

MPSSE is an FTDI function that allows different synchronous protocols to be configured on any available data channel. 
Once the FPGA has been configured, channel B of FT2232H can be reconfigured, using MPSSE, to operate as general purpose IO pins.

I think this opens up a lot of interesting possibilities.

Hope the idea is a little clear; what do you think?

73 Johan

Pierre Martel

Jan 4, 2021, 8:01:59 AMJan 4
to pa3gsb, Radioberry
i think this idea is very good, 
but does the usb link provide enough bandwidth to support the maximum data stream the fpga can produce?

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Jan 4, 2021, 9:07:58 AMJan 4
to Radioberry
Bandwidth figures:

Running a program on a W10 PC

(will do the same on a RPI)

Type = 0x8
ID = 0x4036014
Description = UM232H

Device with serial number found

Read 1GB from the FTDI in 26.3 seconds.
Average read speed: 326.3 Mbps.

(Running with 254 protocol)

Also did a test on RPI-4 ; i got >100Mbps with around 12% CPU load running 1G data transfer.

73 Johan

Op maandag 4 januari 2021 om 14:01:59 UTC+1 schreef


Jan 4, 2021, 10:12:48 AMJan 4
to Radioberry

a (bad) graphical view of the idea


Op maandag 4 januari 2021 om 15:07:58 UTC+1 schreef pa3gsb:


Jan 4, 2021, 4:16:11 PMJan 4
to Radioberry
Johan and the group,

I suppose FT232H bandwidth is good to run Protocol1.
This device is so common with the price of around 20 USD here that I would like to do a test once FPGA code as well as a firmware/driver of Radioberry are ready.


2021年1月5日火曜日 0:12:48 UTC+9 Radioberry:

Jan 7, 2021, 2:13:10 AMJan 7
to Radioberry
Hi Johan,

I like your proposal and think it would an interesting and unique enhancement of the radioberry.

Bandwidth usage can be estimated. Each IQ sample is 24 bits of I and 24 bits of Q data for 48 bits total. If you realize 100Mbs, then you have 100e6/48 = 2.083 MHz total IQ bandwidth. This is just over 5 384kHz receivers or 10 192kHz receivers. I think you will run into RPi4 limitations processing and demodulating this much data before hitting bandwidth limitations. You might also include bandscope data. The original openHPSDR Hermes ran fine for many people over 100Mbs ethernet for years. If you really want more bandwidth, there are USB3  FT600/FT601 devices, but they are a bit more expensive and not as widely used and available.




Jan 8, 2021, 8:27:06 AMJan 8
to Radioberry
Hi Steve,

I did look to the openhpsdr project; their inital project was also using an USB interface.

Implementing the protocol 1 ; i have seen  the code in pihpsdr.... did not pay too much attention!

One of the advantages is that the radioberry can be used by other platforms.

73 Johan

Op donderdag 7 januari 2021 om 08:13:10 UTC+1 schreef


Jan 8, 2021, 9:51:39 AMJan 8
to Radioberry
First diagram of a setup.

Op vrijdag 8 januari 2021 om 14:27:06 UTC+1 schreef pa3gsb:
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