Remote Controlled Eight-Relay Board
PART IV
- An RC Firework Firing Device
Overview
I
am making a remote control (RC) device. It allows me to independently switch
eight relays and control various items. When I press buttons on a
small keypad, instructions will be decoded and transmitted via a
microwave RF packet transceiver (@868 MHz). At the other end (up to 100m
away!) another transceiver decodes the message and switches the relays
ON or OFF.
For my first application, I am using the main components described in Parts I to III, to construct an RC firework firing device. Here's a quick re-cap of relevant posts.
Part I - Analogue Keypad as Input device. The remote control incorporates a small inexpensive analogue keypad, connected to an Arduino Uno. The Arduino handles the scanning and decoding of the keys pressed on the pad.
Part II - Using the RF12 Board by JeeLabs. I'm using a pair of RF12 modules on boards by Jeelabs, connected to Arduinos. These enable data sharing among common network groupings. I am just using them for RC, although they are capable of much more.
Part III - Eight Relay Module. I am using a relay module to provide power some firework igniters. It's an optically isolated 8-relay module, again controlled by an Arduino. The igniters are by Talon. See link for a demonstration of how they work.
Firing a firework.
When I press a number 1 to 7 on the keypad It should send a data-packet over RF, and trigger one of the relays (1-7). This will supply sufficient power to take the Talon igniter up to white heat and light the firework's fuse.
Safety
When setting off fireworks, safety is a major consideration, so I want to incorporate some safety features into my device. I started by thinking about a Safe Operating Procedure (SOP) which would guide the development of the physical device and the code.
These are some ideas that came to mind:
For my first application, I am using the main components described in Parts I to III, to construct an RC firework firing device. Here's a quick re-cap of relevant posts.
Part I - Analogue Keypad as Input device. The remote control incorporates a small inexpensive analogue keypad, connected to an Arduino Uno. The Arduino handles the scanning and decoding of the keys pressed on the pad.
Part II - Using the RF12 Board by JeeLabs. I'm using a pair of RF12 modules on boards by Jeelabs, connected to Arduinos. These enable data sharing among common network groupings. I am just using them for RC, although they are capable of much more.
Part III - Eight Relay Module. I am using a relay module to provide power some firework igniters. It's an optically isolated 8-relay module, again controlled by an Arduino. The igniters are by Talon. See link for a demonstration of how they work.
Firing a firework.
When I press a number 1 to 7 on the keypad It should send a data-packet over RF, and trigger one of the relays (1-7). This will supply sufficient power to take the Talon igniter up to white heat and light the firework's fuse.
Safety
When setting off fireworks, safety is a major consideration, so I want to incorporate some safety features into my device. I started by thinking about a Safe Operating Procedure (SOP) which would guide the development of the physical device and the code.
These are some ideas that came to mind:
- A standardised sequence of actions to wire the igniters, connect them to fireworks, power devices and arm devices.
- Key switch
- Missile switch cover
- Visible and audible power / arming indicators.
- PIN number to protect keypad entry
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