Jdog Testing video

Early testing of the Jdog system

Demo of air (well almost) and ground targets.

Jdog is reading PWM output from the standard RC receiver, so is fully remote control.

Range of the jdog is not very impressive yet, but that is an easy problem to solve with a bit more power and some lenses.

Arduino Frequency Generation

Probably a useful read for anyone trying to accurately generate frequencies in the kHz range using an arduino.

I need to accurately produce 38kHz signals for IR communication projects.
Not all pins give the same frequency output for the same code.

Results in brief: avoid PWM pins if you are not actually using the PWM feature.
In my code instructions took about 4microseconds per half wave form cycle.

Full results after break:

JDog Progress

JDog (J44 RC Dogfight System) Progress Report:

Prototype board has been soldered up.

Works well so far. Have had to re-think methods of reading PWM input form the receiver. Just need to write the arduino code now.

Prototype PCB's

Making of the Jdog (J44 RC Dogfight system) PCB's:

After several attempts and plenty of learning by trial and error the best way I found (I make no claims to be an expert, so do not consider this a definitive guide) for making custom PCB's was:


Using Pre-Sensitised copper-clad board from Maplin (sensitised to UV).

Print off PCB layout (designed on KiCad) on OHP paper.

Double up layers of OHP printed PCB design. This prevents any scratches or marks on the design on one of the layers effecting the finished PCB.

Padded the inside of a CD case and used the CD case to hold the OHP paper and PCB in contact.

Exposed the PCB with a 4W LED array held about 0.4m away to give an even exposure.
An exposure of about 15 min seemed to work well.

Develop with Sodium hydroxide (1teaspoon NaOH in about 250ml of water), use a soft paint brush to brush off the developed mask. Mask developed very quickly (about 1-2 min).

Patch any breaks in the etch resist with an etch resist pen.

Etch the copper (with ferric chloride), use a sponge (dab more etchant on areas etching slowly) to ensure the PCB develops evenly. PCB took about 15min to etch (I suspect the etchant I was using was a bit old, may be a bit quicker with fresher etchant).

Clean PCB.


Note: Take care with the Sodium Hydroxide and the PCB etchant.

Status of RC Dogfighter systems

Prototyping stage:

Currently I have some custom PCB's waiting to be soldered up and tested.

The arduino code needs to be written.

I also need to come up with a good design for the smoke unit.

Talcapult: Introduction

Why/What?

In brief: A cheap way of making things look like they have just exploded.

Aim: Cheap, safe, more flexible alternative to pyrotechnic systems (not that I don't love blowing stuff up, I just can't afford to most of the time).

How it works: It catapults talcum powder into the air which quickly disperses and looks like a mini mushroom cloud.

This project is a spin off of the RC DogFight project.

The talcapult is placed on the ground and reacts to IR. When it detects a hit either from a Duino Tagger or a RC plane mounted IR tagger system it will launch talcum powder into the air giving a mini mushroom cloud.


Multiple units could be controlled by a single arduino.

The project will allow for a much more interesting laser tag / duino tag / RC dogfight game: Adding visually impressive "explosions" to the games.

Imagine your JDog equipped RC plane swooping in on a few model tanks, picking a target and shooting, then seeing the explosive cloud billow up as you shoot it.