Drop

A Custom Strobe Light Control System

A multi-part system built for the Raspberry Pi, to control modified strobe light kits produced by Chaney Electronics and sold by Electronics Goldmine. Control of an array of strobe lights is done over wifi via web application interface.

Software components include:

rpi-cd4094 - An API for controlling CD4094 CMOS 8-bit serial to parallel bus registers.
A web application powered by Tornado to provide a GUI control interface powered by Bootstrap.
StrobeController - A class that brings together Registers, Counters and Operations to do some interesting (hopefully) things.

Hardware:

Raspberry Pi 3 B+
PAU05 - USB WiFi Dongle
Strobe trigger/driver circuit
Chaney Electronics Strobe Light Kit
Custom circuit to allow for +5v pulse triggering of the strobe

IGBT Resources:

Parts:

https://www.mouser.com/datasheet/2/698/REN_r07ds0750ej0100_rjp5001app_DST_20120426-1999273.pdf

Strobe Circuits:

DIY IGBT CONTROLLED 1000WS FLASH UNIT
FORUM POST: familiar with IGBT? how to use it in a strobe flash circuit?
Xenon Strobe Light - Uses SCR but maybe could be modifed to use IGBT
Xenon Strobe Light Control Circuit(s)

Filtering Trigger Pulses to Thumps:

Setup

Prepare an SD card for the Raspberry Pi using Raspberry Pi Imager

Raspi OS Lite
Use your favorite configuration for SSH access

Install Software

sudo apt-get update
sudo apt-get install -y git python3-pip pigpio python3-pigpio tornado python3-decouple
Navigate to the install directory cd /usr/local/src
sudo git clone https://github.com/phillipdavidstearns/drop.git
sudo git clone https://github.com/phillipdavidstearns/rpi-cd4094.git
python3 -m pip install -e ./rpi-cd4094
sudo cp ./drop/drop.service /lib/systemd/system/
You can do all this from the user's home directory, but you'll need to symlink to make the systemd service work sudo ln -s /home/user/drop /usr/local/src/drop
sudo systemctl daemon-reload get systemd to take in the changes
sudo systemctl start pigpiod fire up the pigpio server daemon
sudo systemctl start drop start the controller
sudo systemctl status drop check on it
sudo systemctl enable drop start on boot if it all looks good

Setup WiFi Direct

These steps require the use of a USB WiFi dongle capable of AP mode. The Panda PAU05 WiFi USB dongle does this for about $10.

sudo apt-get install -y hostapd dnsmasq netfilter-persistent iptables-persistent
sudo systemctl unmask hostapd
sudo systemctl enable hostapd
sudo nano /etc/dhcpcd.conf and add to the end:

interface wlan1
    static ip_address=10.10.10.1/24
    nohook wpa_supplicant

sudo nano /etc/sysctl.d/routed-ap.conf to enable packet forwarding

net.ipv4.ip_forward=1

Setup packet routing

sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
sudo netfilter-persistent save

make a copy of the default config file: sudo cp /etc/dnsmasq.conf{,.bak}
configure dnsmasq: sudo nano /etc/dnsmasq.conf

interface=wlan1
dhcp-range=10.10.10.5,10.10.10.250,255.255.255.0,24h
domain=wlan
address=/gw.wlan/10.10.10.1
# Specify the default route
dhcp-option=3,10.10.10.1
# Specify the DNS server address
dhcp-option=6,10.10.10.1
# Set the DHCP server to authoritative mode.
dhcp-authoritative

enable wifi just in case sudo rfkill unblock wlan
sudo nano /etc/hostapd/hostapd.conf

country_code=US
interface=wlan1
driver=nl80211
ieee80211n=1
wmm_enabled=0
ssid=DropControllerDirect
hw_mode=g
channel=5
macaddr_acl=0
ignore_broadcast_ssid=0

# WPA Authentication
auth_algs=1
wpa=2
wpa_passphrase=A_Super_Secret_Password
wpa_key_mgmt=WPA-PSK
rsn_pairwise=CCMP

Reboot and activate AP with sudo systemctl start hostapd.service

Controls

Connect to the WiFi network you setup in the steps above.
Navigate to drop.local in a browser.

Register Settings

This system is built around an simple 8-bit register. These controls allow you to set and perform basic manipulations to the register. In order for changes to be updated and pushed to the strobes, the run button in the Timing Control section must be active.

reset - sets all the register bits to 0
invert - inverts each bit in the register
random - randomizes all bits in the register
8x checks are use to set the state of the register. All check states are pushed on the change of any check.
set - pushes the state of the checks to the register for next update

Linear Feedback Shift Register Settings (LFSR)

enable - turns this feature on/off. when enabled, any change to the above settings updates all settings to the current state displayed by the gui.
direction - dropdown sets the direction of the shift register
flip - changes the direction of the register to opposite of the direction drop down.

Taps

enable - whck checked, updates to the Q settings are made live.
Q - selected a register bit, addressed 0-7, to be XOR'd with other enabled Taps and Mod sources and fed into the register.
randomize - randomizes the Q value

Mod

enable - whck checked, updates to the Q and source settings are made live.
source - dropdown selects a counter division to use
Q - selected a counter bit, addressed 0-7.
randomize - randomizes the Q value

Strobe Settings

update
live
enable

Invert

Inverts the register on each on/off transistion.

on - the amount of transitions until the invert toggles to the on state.
off - the amount of transitions until the invert toggles to the off state.
invert - enables this section of the strobe mode

Mute

Toggles the output enable on each on/off transistion.

on - the amount of transitions to remain enabled.
off - the amount of transitions to remain disabled.
mute - enables this section of the strobe mode

Timing Controls

duration - set the duration of each trigger
current - fetches the current duration running and applies it to the gui

...to be continued...

phillipdavidstearns/drop