Raedme

README

PiFunk Radio Transmitter - with FM/AM-Modulation for HAM-Bands

Early Experimental!

Acknowledgements

based on PiFM/AM-Scripts

Configurations

Get this program via git or download it:

git clone https://www.github.com/wodowiesel/PiFunk

To configure the Pi for modules via menu (I2C, UART etc.): sudo raspi-config

or manually via command: sudo modprobe w1-gpio,gpiopin=4

Using w1-gpio sometimes needs a 4.7 - 10 kΩ pullup resistor connected on GPIO Pin

(if you have problems deactivate 1-wire config!)

1-Wire by default BCM4 setting needs to be activated in boot-config for autostart

Manually open with nano-editor: sudo nano /boot/config.txt (i provide one too)

check/add lines:

dtoverlay=w1-gpio,gpiopin=4,pullup=0 add pullup=1 if needed

dtoverlay=audio=on for bcm audio

optional:

dtoverlay=i2c1-bcm2708 for I2C Bus

enable_uart=1 for UART RX & TX

init_uart_baud=9600

dtparam=spi=on for SPI support

dtoverlay=pps-gpio,gpiopin=18 for GPS-device

Listen to GPS 1 PPS signal for Pi Clock (PIN 18) sync

sudo nano /etc/modules opens modules.conf with text editor (provide one too)

pps-gpio Add this line

Save your edits with ctrl-o <return/enter> then exit with ctrl-x

Installations

First update & upgrade system:

sudo apt-get update for system updates

sudo apt-get upgrade for system upgrades

You will need some libraries for this:

a) sudo apt-get install libsndfile1-dev or download it directly SND

b) sudo apt-get install libraspberrypi-dev raspberrypi-kernel-headers for Kernel & Firmware

c) sudo apt-get install python-dev python3-dev for py3

d) RPi-lib (I use v0.6.5 from Nov 2018, also in repo)

sudo wget https://pypi.python.org/packages/source/R/RPi.GPIO/RPi.GPIO-0.6.5.tar.gz

then extract tar -xvf RPi.GPIO-0.6.5.tar.gz

and install it:

sudo pip-3.7 install RPi.GPIO for Py3 (easiest way)

or sudo pip install RPi.GPIO for Py2

or alternative way: sudo apt-get -y install python3-rpi.gpio

Compiler installation:

a) GNU C Compiler sudo apt-get install gcc or g++

b) GNU GDB Debugger sudo apt-get install gdbserver

sudo reboot then reboot to apply the changes

Build

Navigate to directory:

a) cd PiFunk with default path: /home/pi/PiFunk

b) GCC Compiler flags:

-g3 for compiler debugger informations (0-3 level, 2 is default)

-gdbserver for GNU debugger informations

-Wall for debug warning informations

-v Print compilation verbose informations

-std=c99 (sometimes gnu99 or as iso -std=iso9899:1999) for C99-standard or -std=c++17 or (11/14 as you like)

-Iinclude for using include-directory with headerfiles

-I/opt/vc/include/ for loading bcm-header folder

-L/opt/vc/lib for loading bcm folder

-Llib for using library-directory

-lm for math-lib is obligatory!

-lbcm_host for loading firmware v1.20190718

-lpthread lib for process threads

-lgthread lib for graphic threads

-lsndfile -l links libname for ALSA "snd"-lib

-shared for generating shared object libraries

-c for compiling without linking for making object

-D_POSIX_C_SOURCE=199309L for posix needed with bcm

-D_USE_MATH_DEFINES for math lib

-DRASPI1 defines the macro to be used by the preprocessor (here the PI1 model or 0-4, else std-values)

-> will be detected by my the makefile via the type of the ARM-Processor

(other macros possible if in the C-code implemented)

-fPIC for generating position independent code (PIC) for bigger programs

-O3 for Optimization Stage 1-3 (memory, speed etc.) via compiler

-o for output-filename flag

Generating libraries:

a) Image of the GCC Flow-diagram for generating Libraries

*.c=C-source ccode, *.h=headerfile, *.i=assembled preprocessor C code, *.s=preprocessed assembler code,

*.o=compiled object, *.lib=library object, *.a=archive object, *.so=shared dynamic library object,

*.out=default binary, pifunk(.bin)=executable binary (program)

b) manually compiling/linking libraries:

sudo gcc -g3 -Wall -std=c99 -Iinclude -Llib -lbcm_host -lm -lsndfile -lpthread -lgthread -O3 -fPIC pifunk.c -shared -o include/pifunk.i lib/pifunk.s lib/pifunk.o lib/pifunk.a lib/pifunk.lib lib/pifunk.so

c) manually compiling/linking executable binary:

sudo gcc -g3 -Wall -std=c99 -Iinclude -Llib -lbcm_host -lm -lsndfile -lpthread -lgthread -O3 -fPIC pifunk.c -shared -o bin/pifunk.out bin/pifunk

d) optional:

Flags:

-march=armv6l architecture version of ARM ("native" is auto option)

-mtune=arm1176jzf-s special architecture type tuning

-mfloat-abi=hard floating-point ABI to use, Permissible values are: ‘soft’, ‘softfp’, ‘hard’

-mfpu=vfp virtual floating point hardware module

-ffast-math increase speed for float ops and outside the IEEE-standard and deactivates errno-functions

sudo piversion for checking your piversion

Makefile commands:

sudo install for installing pifunk files incl. build folder

sudo uninstall for uninstalling pifunk files

sudo make with pre-configured flags for compilation for all Pi's

sudo clean for removing pifunk.out and pifunk.o files in bin folder if necessary

Preparations

Hardware-Setup:

a) Use (original) power supply 10 W, 5 V @ ~2 A or ~5 V/500 mA via miniUSB 2.0 or 5 V Pins possible)

b) Check specifications: my Pi B+ v1.2 @ 700 MHz / 512 MB RAM on ARM processor with driver bcm2835-v1.55

-> SoC from Broadcom depending on pi model: BCM2835, BCM2836, BCM2837, BCM2837B0, BCM2837, BCM2837B0, BCM2711

for more infos on other boards just visit Adafruit

or Wikipedia Spec Summary

c) Antenna to GPCLK0 (GPIO 4, PIN 7) for PWM (Pulse with Modulation)

@ 2-4 mA (max. 50 mA on ALL PINs and 16 per bank!)

Antenna should be grounded (see Pinout image) to prevent noise and other problems
For transmission you should use tested/certified antennas with mounts (BNC/SDA/PL - m/f) if possible
Tip: You could use just a copper wire for antenna:

CB 11 m-Band (lambda/2, 5.5 m, 216.535" in) and 70 cm-Band (PMR) (lambda(1/4), 17.0 cm, 6.7" in)

Pinout

d) You can try to smooth it out with a 1:X (3-9)-balun if using long HF antenna

Dummy-load: 1-100 W @ 50 Ohm "cement" or similar (aluminium case) with cooler for testing

e) For handling overheating of the Pi's processor use cooling-ribs with fan (5 V DC/0.2 A - 20x20 mm)

you can overclock the Pi if you want to on own risk but it's not recommended

f) RTC: Module DS3231 uses 3.3 V (PIN 1), SDA0 (PIN 3, GPIO0 on I2C), SCL0 (PIN 5, GPIO1 on I2C) & GND (PIN 9)

-> need to activate I2C in pi config!

RTC

g) GPS: Module Neo 7M uses

5 V (PIN 4), GND (PIN 6), RX to UART-TXD (GPIO 14 PIN 8), TX to UART-RXD (GPIO 15, PIN 10), PPS to PCM_CLK (GPIO 18, PIN 12)

it prints in NMEA format so change config ttyAMA0 to tty1

sudo cat /dev/ttyAMA0 or alternative sudo cat /dev/ttyS0

-> need to activate UART (serial 0) in pi config! Yes here crosswiring!! -> (RX of GPS receives what Pi TX'ed)

GPS

h) Morsecode-table:

Morsecode

Run

Run with admin/root permissions:

Arguments: would be best to input in this specific order to prevent problems

Use '. dot' as decimal-comma separator!

[-n <filename (.wav)>] [ -f <freq (MHz)>] [-s <samplerate (kHz)>] [-m <modulation (fm/am)>] [-c <callsign (optional)>] [-p <power 0-7)>]

extra single menu-flags: -> no further argument needed

[-a] for assistant in step-by-step

[-h] for help with more infos and arguments

[-u] for extra menu (csv, commandline)

default: sudo ./pifunk -n sound.wav -f 446.006250 -s 22050 -m fm -c callsign -p 7

Radio works with .wav-file with 16-bit @ 22050.000 [Hz] mono / 0.1-700 to 1500 MHz range depending on the Pi

it's recommended not to transmit on frequencies higher than the processor speed (at the moment) but results would be interesting to know

explicit CTSS-Tones (38 included) for PMR can be found here: CTSS

Disclaimer

Warnings/Caution:

Private Project! Work in Progress (WIP)
I'm not a professional so NO guarantees or warranty for any damage etc.!!
Usage at your own risk !!
Check laws of your country first! Some Frequencies are prohibited or need a HAM-License!
Pi operates with square-waves (²/^2)!! Use Low-/High-Band-Pass-Filters with dry (not electrolytic) capacitors

(C=10-100 pF) with solenoid (ring) toroid (ferrit) chokes (B=10-50 uH like the FT37-43)

or resistors (R=10 kOhm), diodes to prevent backflow

transmission (TX) simultaneously on permitted frequencies! -> Bandpass-Diagram