Transmission of arbitrary waveforms

README.md

@@ -1,3 +1,20 @@
+# MODIFIED CARIBOULITE
+
+This is a non-official branch of cariboulite.
+Features:
+ - performance upgrades
+ - transmission of arbitrary waveforms
+
+The guide on how to use this version is in docs/notes/tutorial.txt
+
+___
+ _
+___
+ _
+___
+_
+
+
 # CaribouLite
 CaribouLite is an affordable, educational, open-source SDR evaluation platform and a HAT for the Raspberry-Pi family of boards (40-pin versions only). It is built for makers, hackers, and researchers and was designed to complement the current SDR (Software Defined Radio) eco-systems offering with a scalable, standalone dual-channel software-defined radio.
 
@@ -22,6 +39,7 @@ Due to the architectural changes in RPI5 - the new I/O controller called "RP1" c
 So, if you intend to use CaribouLite on RPI5 please don't - it won't work. Why was the SMI interface deprecated by Broadcomm (either from its hardware or kernel SW support)? Most probably due to the same reason this interface was not documented in the first place - no interest in supporting a high-speed external interface within the 40-pin connector.
 
 Edit: The workaround we are working to support RPI5 anyway - trying to utilize the Display and Camera I/O pins from the 40-pin connector to stream information - FPGA + Kernel module adaptation.
+Edit2: A unofficial developer (Matteo Serva) is working on supporting the RPI5 by leveraging multiple SPI interfaces
 
 # Getting Started & Installation
 Use the following steps to install the CaribouLite on your choice of RPI board
@@ -67,6 +85,11 @@ So currently, sudo'ing is needed whenever CaribouLite is accessed (including sud
 
 To compile the API library and SoapySDR API from code please click [here](/software/libcariboulite/README.md)
 
+# Transmitting a signal
+
+There is an experimental feature for transmitting arbitrary waveforms.
+The guide on how to use this version is [here](/docs/notes/tutorial.md)
+
 # SMI Interface
 
 Unlike many other HAT projects, CaribouLite utilizes the **SMI** (Secondary Memory Interface) present on all the 40-pin RPI versions. This interface is not thoroughly documented by both Raspberry-Pi documentation and Broadcomm's reference manuals. An amazing work done by [Lean2](https://iosoft.blog/2020/07/16/raspberry-pi-smi/) (code in [git repo](https://github.com/jbentham/rpi)) in hacking this interface has contributed to CaribouLite's technical feasibility. A deeper overview of the interface is provided by G.J. Van Loo, 2017 [Secondary_Memory_Interface.pdf](docs/smi/Secondary%20Memory%20Interface.pdf). The SMI interface allows exchanging up to ~500 Mbit/s (depending on the FPGA, data-bus width, etc.) between the RPI and the HAT, and yet, the results vary between the different versions of RPI. The results further depend on the specific RPI version's DMA speeds.

docs/notes/tutorial.md

@@ -0,0 +1,103 @@
+
+# general info
+
+tested on raspberry pi zero 2W, running raspbian bookworm, headless (no GUI)
+
+
+# how to use the modified cariboulite
+
+steps:
+- install the OS
+- install dependencies
+- install cariboulite
+- install cariboulite matteoserva
+- compile driver
+- compile software
+
+- disable wifi powersave
+- load driver
+
+- run tx test
+- run transmit samples
+- run gnuradio transmit
+
+
+## install latest raspbian bookworm, 64 bit
+```
+raspberry pi imager to install rasbpian bookworm (latest), 64 bit. With or without gui.
+The raspberry imager allows you to enable ssh and configure wifi before installing, so there is no need for a monitor.
+```
+
+## install dependencies
+
+```
+apt-get install git socat screen
+apt-get install libsoapysdr-dev gnuradio soapyremote-server 
+apt-get install buffer
+apt-get install gir1.2-gtk-3.0
+```
+
+## install original software
+
+```
+git clone https://github.com/cariboulabs/cariboulite.git cariboulite_original
+cd cariboulite_original
+```
+
+## install my branch in cariboulite
+```
+git clone https://github.com/matteoserva/cariboulite.git cariboulite_matteo
+cd cariboulite_matteo
+git checkout transmission_fix
+```
+
+## compile kernel driver
+```
+cd cariboulite_matteo/driver
+mkdir build
+cd build
+cmake .. && make
+```
+
+## compile software
+```
+cd cariboulite_matteo/software/libcariboulite
+mkdir build
+cd build
+cmake .. && make
+```
+
+## disable wifi powersave
+```
+sudo /sbin/iwconfig wlan0 power off
+```
+
+## load fpga
+(ignore this)
+```
+~printf "3\n2\n99\n" | ./cariboulite_test_app ~
+```
+
+## launch transmission test
+```
+./tx_test -c 1 -f 433125000 -r 4000000 -w 0 - 
+```
+
+## transmit from gnuradio
+```
+socat tcp-listen:9999,fork - |  ./tx_test -c 1 -f 433125000 -r 400000 -w 0 -g 0 -e 1 -
+```
+follow the example workflow in gnuradio_tx.png
+
+## planned features
+
+- Soapy TX
+  - fix numeric range in exchanged data
+  - wrong data arriving at the transmitter
+
+- Raspberry pi 5 support
+  The original developers are trying to use the camera port as a high speed device.
+  My approach is to use two RP1 dual spi ports. In future this can be replaced with a quad-spi but
+  right now the required pins are not routed by the caribou lite.
+
+