Newbie with some questions

TwigMort

New Member
Good evening, thank you for allowing me to join.

I am an absolute novice when it comes to microprocessors and am in need of some help and advice before embarking on a project. First though a little background on me so you can gain an idea of my abilities and potential success! I am a mechanical engineer by trade with 22 years and a basic understanding of electronics. I have built a few little electronic kits (velleman type stuff) and dabble a little with some breadboard circuits from time to time. I was once a member of a game modification group, where I learned some Python coding. I have also created some code in Visual Basic for use in the MS Office suite, and as a kid had a Spectrum which wasted hours typing in the BASIC code from magazines. Also learned enough BASIC to write my own programme way back!

The project I want to embark on is for a remote control drone I have. It has an IR emitter for 'battling' otehr drones, but I would like to create a ground based 'target' for practice at home. I have so far made a basic target using a TSOP receiver which functions well, but reacts to pretty much any IR transmitter (such as a remote control). While researching ways to try and isolate it purely to the drones emitter I came across the PICAXE microprocessors. It seems the 08M2 would be able to support this, allowing me to try and 'decode' the IR wavelength so the chip reacts to that and lights up an LED or two, plus perhaps play a sound.

My questions for you then are, would PICAXE be suitable for this? Would the 08M2 Starter pack be the right choice and would this be within my capabilities once I have refreshed myself with some coding?

I would appreciate any feedback and support you might be able to offer.
 

inglewoodpete

Senior Member
Welcome to the PICAXE Forum.

I've not used the 08M2 starter pack but have just had a look at the kit. It looks ideal for your purpose, with an area available for wiring up the few components that you will need for your project. Wiring an LED is described in Manual 3, page 9 and the TSOP IR Receiver module is described in Manual 2, page 128, along with a description of the IRIN command.

This is where things will probably get a little more complicated. The firmware in the PICAXE is written to decode signal a Sony TV remote control. Your drone will almost certainly not transmit Sony codes! However, if you are just using it for practice, you will probably not need to decode the IR signals.

The TSOP receiver is tuned to receive modulated IR signals in the range 35 to 40 kHz and. When it receives the IR carrier, it pulls its output low and releases it when the carrier is removed, allowing the pullup resistor to pull the output high.

By not using the IRIN command and simply monitoring the TSOP receiver's output on an input pin, the PICAXE could react and flash an LED.

Sound like a fun project. You might even get a free haircut if the drone strays too close to you:).
 

hippy

Technical Support
Staff member
It should be possible to distinguish the drone's 'laser beam' IR from other IR. The key question is how the drone puts out its IR so it can be distinguished as being that 'laser' not IR from a TV remote control.

I am guessing the drone puts out a certain pattern of IR so one would read the IR, check if it matches that pattern, if so score it as a hit, otherwise ignore it.

The question then is to determine what the pattern being looked for would be. That could be determined by monitoring, with an oscilloscope, logic analyser, or a PICAXE monitoring IR. But it might be that someone has already done all that work. Do you have details of what your drone is, manufacturer, model ?
 

TwigMort

New Member
Thanks for the responses so far :)

@inglewoodpete: Yes I have a TSOP that I have already wired and responds to an IR signal from the drone, but as stated it reacts to any IR input in that range (such as TV remote). Still a fun little thing to play with though, but I want to take it to the next level!

@hippy: I believe it does put out a pattern in order to identify a drone. I believe from some reading that PICAXE can be setup to monitor the IR and am sure I have seen where someone has done this in order to read code off a remote. The drone is manufactured by Propel and is one of their Star Wars battling drones.
 

hippy

Technical Support
Staff member
The Propel Star War drones look quite neat. Unfortunately I couldn't find any info on what the IR 'laser' signal would be.

So that means some self investigation. Logic analyser would be best, oscilloscope second best. I believe someone posted details to the forum on how to attach a TSOP IR receiver to a sound card and use that with PC scope software. It's also possible to capture and analyse the signal with a PICAXE -

http://www.picaxeforum.co.uk/showthread.php?26791-IR-Scope
 
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