CaribouLite from Caribou Labs is a new open-source dual-channel Raspberry Pi SDR HAT that offers up to a 6 GHz tunable range. Easily customizable, this new open-source board has been specifically designed for Raspberry Pi 40-pin mini PC range and complements the SDR current eco-systems offering a scalable, standalone dual-channel software-defined radio.
With the IceStorm FPGA toolchain and fully open source code and documentation made available from the company, the customers can easily control, modify and program the device through a Raspberry Pi computer. CaribouLite makes use of the SMI (Secondary Memory Interface) present on all the 40-pin RPI versions. The SMI interface allows up to ~500Mbit/s data exchange between the FPGA and Raspberry Pi.
CaribouLite gives two Tx/Rx SDR channels viz. 30-6000 MHz, and Sub-1GHz. The 4MSPS I/Q samples, i.e. Tx and Rx, are transmitted over the RPI’s secondary memory interface, where CaribouLite acts as a high throughput memory peripheral. It has an internal accurate RF clock source (TCXO @ +/-0.5 ppm), low noise Rx capabilities (NF < 4 dB under 3 GHz), and high Tx power (up to 18 dBm). Additionally, it has a fully controllable read / write 8-bit expansion port (PMOD) to support advanced features such as direction finding, synchronization, and more.
High-level APIs like Soapy / GNU Radio of Raspberry Pi are fully supported making it easier for the users to access the complete feature-set of HAT. CaribouLite is powered by the Raspberry Pi’s 5 V rail from the 40-pin header. This further gets converted to 3.3 V thereafter which it gets filtered and down-converted again (using an LDO) to the 2.8 V RF voltage source and the 1.2 V FGPA voltage source. The product is currently in the pre-launch stage over on the CrowdSupply.