PICAXE Lasertag

[Tvmender]

Hi All

I have recently completed my prototype PICAXE Lasertag project. I did in the past work for Laser Quest as an Electronics Engineer and always fancied building my own kit, I then had kids which gave me an excuse!

Some info:

System is based on PICAXE 20M2 of which each pack has 3. The front pack contains the main game processor unit which deals with the IR comms, incoming IR data from 4 x 40KHz IR sensors, serial sound effects communications and battery status monitoring. The second PICAXE purely deals with the displays driving multiplexed LEDs both front and back and on the phaser. The LEDs can be red, green or yellow depending on the team selected and will flash all in tandem when hit.

The rear pack contains the third PICAXE which deals with the real-time radio communications using a 433MHz module (Tx and Rx) a bit like a modem allowing control of the game packs and scoring in real time and some more battery level monitoring. The encoding and decoding is done via HT12D and HT12E decoder/encoders. This communicated with a base station made from a modified version of the pack's rear board and will allow serial comms with a PC for PC based game control.

Sound effects are via the SPE033 MP3 player with 1Gb SD card. Player display is an OLED display.

The phaser contains a 14M2 and deals with encoding the IR data based on the packs ID setting, trigger activation and rapid fire modes and laser activation.

I have utilized the PICAXE 20M2 development board by standing it on risers giving me more PCB space below and the fact the protoboard has most of the supporting hardware on it too further reducing board space.

The PCBs are from JLC and were incredibly cheap (total of about £16 for 15 boards!) and I do love them in black. The phaser casing are cheap water pistols from Amazon and the lasers are low power (although I do make the kids wear those green laser "shades" just in case). I used 2" webbing for the straps and the electronics are encased in IP65 clear fronted WISKA boxes.

Anyway, just thought I would share this! I am still messing around and refining software and hardware but the kids seem to enjoy it! Total build cost of around £200.

 

[lbenson]

Outstanding project! Kudos. Thanks for sharing.

I like those clear-top boxes.

 

[hippy]

I like those clear-top boxes.

They are neat and useful. Usually found as IP-rated waterproof enclosures so not always cheap. One example -

https://uk.rs-online.com/web/p/general-purpose-enclosures/0220490

 

[Tvmender]

I looked at those on RS but shuddered at the price. I made a compromise with these. They do have some manufacturers info on the clear part and other info so not as clean as the ones Hippy mentions.

These were £12 each from my local electrical distributor.

 

[hippy]

They do have some manufacturers info on the clear part and other info so not as clean as the ones Hippy mentions.

One trick for removing silk-screened printing from plastic, clear or otherwise, is to apply a healthy heap of Baking Soda (bicarbonate of soda) and gently rub it away with a damp cloth.

Some printing is easy to remove but some can be stubborn, requires time or a lot of elbow grease. Undiluted washing-up liquid and toothpaste which may be more or less harsh can also be used. All run the risk of dulling the surface so best to test and practice on a sacrificial sample first.

I have found make-up cases for blusher can be useful for some projects and they often have a silk-screened see-through lids and that's worked well for me. And also for removing the silk-screening from plastic DVD players and set-top boxes. Best to do all the surface and use random motions so, if it does dull the surface, it's uniform and not obviously scrubbed. Even if not perfect it can still go unnoticed from a distance.

Baking Soda is also good for dealing with soft rubbery coatings on the back of calculators, phones, remote controls, etc, which has gone sticky and icky, and for removing stubborn grime off soft keypad buttons and enclosures. Best to dismantle so one can wash away any residue under a tap.

 

[Tvmender]

Hi Hippy

That's good advice, there are several boxes which I could do to remove the screen print from. I plan to recycle some old cases for a Tesla coil controller I'm building.

The boxes I used for this project have the details embossed into it so can't be removed. I also learnt that you can't spray paint some plastics without proper primer, it just flakes off! Doh!

A cheaper way to do these boxes would be to cut out an area and cover with perspex.

I plan to build a couple more packs at some point so the kids can play in pairs.

 

[4jaba6]

Amazing Project! Can you kindly post which phototransistor and laser you used? Also the circuits that interfaced these sensors to the 20M2?

I have been using the schematic from Dave Bodnar at trainelectonics.com/Laser_Train_Detection.
Am using a Qiaba Laser 650nm 5mW and a Vishay phototransistor 850nm. Collector to +5v, Emitter splits between 20M2 pin and 10k Resistor and then ground and Base receives the laser beam. Am having mixed results. It may be due to difference between nm of laser and phototransistor. Below is the schematic from Dave Bodnar's detailed article.
( if the schematic attachment does not work, I believe it can be seen on p. 25 ( the 14N2 ) of the Trainelectronics link. )
PICAXE Schematic

 

[Tvmender]

Hi 4jaba6

The receivers are TSOP31240 40KHz IR receivers. The infrared LEDs are Vishay TSAL6200. The laser is only used for aiming and sends no data. Positioned above the laser is the infrared LED which is fitted with a small lens and recessed into a tube for optimal focal length.

The TSAL6200 is driven using a constant current driver at around 80mA. The infrared data is transmitted from a dedicated 14M2 using the PICAXE IROUT command using the standard Sony SIRC protocol which the PICAXE uses.

The receiver is interfaced as per the datasheet: https://www.vishay.com/docs/82492/tsop312.pdf with the OUT pin connected to a dedicated input pin of the 20M2 main processor. As these are open collector outputs they can be connected in parallel with no issue. I have two in the phazer connected this way for top and side hits.

I have attached an image of the circuit diagram for both the TSOP and TSAL devices.

Hope this helps.