PageOutline = OsmoSDR Hardware =
The OsmoSDR hardware consists of an oscillator, Zero-IF silicon tuner, ADC, FPGA and a USB-capable microcontroller.
The block diagram looks like this:
=== Atmel AT91SAM3U Microcontroller ===
The SAM3U is a quite powerful but inexpensive Cortex-M3 based Microcontroller. What makes it special compared
to many other devices is its integrated USB 2.0 High-Speed device, combined with scatter-gather DMA and an internal
memory/bus architecture that can actually drive the USB 2.0 at 480Mbps without any problems.
The SAM3U [wiki:Firmware] will be available as Free Software / Open Source in our git repository.
- Homepage: http://www.atmel.com/sam3u
- Data Sheet: http://www.atmel.com/dyn/resources/prod_documents/doc6430.pdf
=== Lattice XFP2 FPGA ===
The FPGA is mainly intended to interface the ADC with the SSC peripheral of the SAM3U. However, it is reasonable
to assume it can do some simple filtering, too.
The FPGA design will be available as Free Software / Open Source in our git repository
=== Analog Devices AD7357 ADC ===
This ADC provides two channels (I and Q) and can run at up to 4.2 Megasamples / second and provides 14 bits of resolution.
- Homepage: http://www.analog.com/en/analog-to-digital-converters/ad-converters/ad7357/products/product.html
- Data Sheet: http://www.analog.com/static/imported-files/data_sheets/AD7357.pdf
=== Silicon Tuner ===
=== !SiLabs Si570 Oscillator ===
The Si570 is a 10MHz to 1.4GHz programmable oscillator. The exact frequency can be set and adjusted via an I2C interface.
OsmoSDR is prepared for a number of extensions...
=== GPS locked clock ===
There is a 1pps input on OsmoSDR. It can be used to slave the OsmoSDR clock to the 1pps output of a GPS receiver in order
to achieve high clock accuracy.
=== Transmitter ===
OsmoSDR is a pure Rx device. However, there are extension headers of both the SAM3U and the FPGA which permit stacking
of a future transmitter board.
=== Filters ===
There are jumpers for the differential analog I and Q baseband signals between the mixer/downconverter and the ADC. This can
be used to plug custom analog base band filters into the signal chain.