Newbee needs suggestions for project

[robert.higginson]

Hi,
I have played around with the buggy and school experimenter boards and feel confident enough to start creating my own individual project. I have an old battery operated dog that I feel would be a good project to start with. I need a system to control the 3 motors (forward and backwards), 2 LEDS, and a few sensors (what types these would be?) to detect if anything is in front of it, and ... , if possible ..., to be able to play tunes like the 08M chip.

I was thinking that the PICAXE-18M would be the best choice since my idea would be similar to the buggy (MOD001) I have been using. The dog would roam around the room trying not to hit things and making appropriate noises.

I would like to use a pre-made project board as a starting point but I do not seem able to find one that will enable me to drive 3 motors so I am looking for suggestions on how to proceed or find information.

If anyone could supply a circuit diagram that would be very helpful as I'll have a go at making up the board if need be.

Thanks - in anticipation

 

[westaust55]

I think that YOU need to do some further investigations yourself first and let folks here know more about your proposed “Dog” project.
(that is, help us to help you )

For a start:
1. What is the battery voltage?
2. What are the details, voltage, current, etc for the motors? They are probably simple DC motors but can you confirm this?
3. What are the sensors? (you ask us – how would we know, you have the toy). They could be LDR’s, IR diodes and receivers, or if it is a little more expensive even ultrasonic. So open your toy and have a look.
4. What other sensors exist?
5. What is the existing sound making device – coil speaker, piezo speaker, piezo buzzer?
6. Do all the motors need to be reversible?
7. Do any motors need/want speed control?

All PICAXE chips have the SOUND commands and all M, M2, X1 and X2 parts have the TUNE command.

Why not consider a PICAXE chip with more memory space than the “M” series. These only have 256 bytes of program space.
Read up on the 18M2 or for more inputs and outputs etc maybe even a 28X2.


The CHI035 may be a prospect if you use the 18M2 and do not need all 3 motors to be reversible
http://www.rev-ed.co.uk/docs/chi035.pdf

If you go for an PICAXE 28X2 then maybe the AXE020 board again if you do not need all 3 motors to be reversible


As you can see, YOU have to define your project somewhat better before folks can help you with much.

 

[BeanieBots]

As Westy points, YOU need to do a bit more.
Reversing a speed controlled motor can be quite simple and only requires two outputs, so the 28pin project board would be able to control at least four motors in both directions. (with a little extra hardware, more if required)

As for sensors, have a browse around the finished section.
Simple options would include ultra-sonic and infra-red.
For example, my hexapod uses two Sharp GPD15 analogue IR range detectors.

 

[robert.higginson]

I have revisited this 'K9 dog' project using a CHI035a board. It currently moves forward/backward, moves head, senses using a srf005 module and now I am looking to have remote control access. I have read the manual and it says that the infrared upgrade can be used with the chi035a board but does not give a lot of information to a newbee. Anyone willing to help with a very simple description of how to achieve this upgrade with reference to the chi035a board rather than an electronic ciruit diagram. -- Thanks

 

[IronJungle]

If moving around and avoiding 'stuff' your goal, you could adapt the SHR project to your toy dog.
See: http://letsmakerobots.com/start

The project is well document, replicated many times, uses a PICAXE, an IR sensor, motordrivers, etc. Anyway, the SHR page will get your mind moving in the right direction.

 

[westaust55]

Here is the datasheet to the Rev Ed Infrared upgrade kit: http://www.picaxe.com/docs/axe040.pdf

If you would like to understand better how the infrared system works and/or maybe "roll your own" then have a read of this IR basics tutorial I previously posted:
http://www.picaxeforum.co.uk/showthread.php?17303-Infrared-(IR)-Communications-Basic-Tutorial

You might also get some further ideas from these Rev Ed datasheets:
http://www.picaxe.com/docs/bot120.pdf
http://www.picaxe.com/docs/bot121.pdf

 

[Bill.b]

Hi Robert

This is a schematic for a bot I built, It may give you some ideas. I suggest you use a servo for control of the head. using the servo to pan the head with either a
SRF005 or a GP2D12 IR distance scanner.

View attachment 28x2bot.bas

Bill