Roll Your Own Prop Controller with PICAXE

[hpropman]

Moderator Note: Moved from the "Prop Controller Comparison" thread. The PIC microcontroller derserves to have its own thread for discussion.

Originally Posted by asterix0

I've considered trying one of these: http://makezine.com/controller/

Ouch - for that kind of money you can make over 20 picaxe controllers. it is a kit that needs to be soldered anyway. The biggest obstacle standing in the way of a homegrown controller like a picaxe seems to the pc board. I am waiting for the new 20X2 chip to be released (nice specs) so that I can design a controller board around that chip. it has 16 I/O lines 15 of which can be set to either inputs or outputs and a top speed of 64MHZ. All the specs can be seen in the link below. The reason I bring this up is that is case anyone is interested we can design the controller and then have the pc boards made up for us. it would cost us about $50 for 3 boards and then cost per board drops the more boards that you order. would you guys be interested in a board that you solder yourself and have a very powerful controller. I am not looking to make any money off this I would sell the boards to haunt forum members at cost plus shipping. what does everyone think?

Here is the link to the new boards. The 28X2 and the 40X2 are already available.

http://www.rev-ed.co.uk/docs/picaxex2.pdf

[robp790]

I would certainly be interested. I like the Picaxe chip for its ease of use. It the conversion of common routines for a Prop1 or Prop2 to a Picaxe version that I have nbot seen done - Yet!

[asterix0]

"The reason I bring this up is that is case anyone is interested we can design the controller and then have the pc boards made up for us. it would cost us about $50 for 3 boards and then cost per board drops the more boards that you order. would you guys be interested in a board that you solder yourself and have a very powerful controller.


How hard would the soldering be? Do you have a preliminary design?

[hpropman]

Originally Posted by asterix0

"The reason I bring this up is that is case anyone is interested we can design the controller and then have the pc boards made up for us. it would cost us about $50 for 3 boards and then cost per board drops the more boards that you order. would you guys be interested in a board that you solder yourself and have a very powerful controller.


How hard would the soldering be? Do you have a preliminary design?

Soldering it not that hard. After you have made a few practice solder joints you should be able to handle it. As for a design right now I was thinking of a board that would use the 20X2 with 16 I/O pins and a some servo connectors, I would also include a voltage regulator so that you can use multiple voltage sources and the programing interface. I do not think that we would need anything else. Did I miss anything that you might want to include? I was thinking of a basic controller like a prop 1 / 2 so that people can have access to the picaxe chip that might not otherwise do so.

[asterix0]

Are you planning to include a high current driver?

[hpropman]

I forgot about that. we can drop a ULN2803A driver chip into the board that would give you 8 high current outputs (500ma per output). anything more than that would require an external transistor or FET.

[fritz42_male]

I'm just beginning a write up on creating a low cost prop controller. I'm basing it on the entry level Picaxe 08M. Initially I'll be using the 08M project board but I'm just finishing the design of a custom adaptable board.

I'm aiming to keep the price as low as possible so there won't be any on-board power regulation - there will be an external regulator with a daisy chain option to run multiple boards off one supply.

[hpropman]

Originally Posted by fritz42_male

I'm just beginning a write up on creating a low cost prop controller. I'm basing it on the entry level Picaxe 08M. Initially I'll be using the 08M project board but I'm just finishing the design of a custom adaptable board.

I'm aiming to keep the price as low as possible so there won't be any on-board power regulation - there will be an external regulator with a daisy chain option to run multiple boards off one supply.

You should check out this guys website he has some nice boards. He writes for nuts and volts and servo magazine.

http://www.jrhackett.net/pcboards.shtml

[fritz42_male]

Thanks for the link. However, my aims are specific to Prop control and those boards are a bit generic. My requirement was for a small simple board that was very adaptable. The attached pic is of the almost finished board.

Features are:

Optional Offboard Power or onboard Power. Onboard is either a battery pack on a PP9 Connector or a CR2032 Button Cell.

Offboard Power In AND daisy chain Power Out. 2 Pin or Screw Terminal

Data connectors can be 3 pin Servo Compatible or Screw Terminal

The 18 Pin socket can be either straight linked for driving Solid Sate Relays, Have a Resistor Pack for driving servos or a ULN2803A for higher current drive requirement. The basic component count is very low.

Daisy Chain option for Sync signal to activate other VLCs

If I order 100 boards I can get them down to $4-$5 US for the bare board. Components excluding the Picaxe 08M would be about $2-$3

Overall, this controller should cost less than $15!

http://img30.imageshack.us/img30/4977/vlcrev2.png

[fritz42_male]

I'll make the board design available as an Express PCB file for thos who can make their own boards.

Also on the cards are a sound amplifier to take a mic or line input - this should allow for a Scary Terry style servo driver. Also a thunder/lightning controller.

I'm also looking at the sound recorder chips (Winbond style) although if I can find a decent little MP3 player, this may be unnecessary.

I envisage that the add-on boards will either stand vertically on the 3 pin connectors or be daisy chained via a servo extension cable.

Anyone interested?