Note to Teachers.
This project involves creating a PCB circuit and a Case, which will produce a compact programmable safety/ decorative unit.
Project costs around £3.00 per unit. A full term recommended though units can be broken down.
Some uses for the product could be: -
Safety light - Pedestrian, Bike. Toothbrush Timer. Quiz Timer. House Badge (use LED’s same colour as house). Decorative Disco Badge. Dice. Christmas / Festive Decoration.
Prior knowledge of programming using ‘Logicator’ or ‘Pic axe and PCB Production would be needed as a teacher.
Knowledge of 2D- Design and PRO/desktop would also be useful although 2 tutorials are included.
Some homework assignments have been included within the design folder to assist with the completion of the product though it would be worthwhile to set further extended tasks based on pupils’ prior knowledge and ability.
Completion of the project would involve a term’s work although this can be broken down into smaller components.
This circuit has been designed using the PIC AXE 08 and the PIC AXE 08M Chip for reasons of cost. They work out at about £1.00 and can be programmed directly from download cable which fits into a computer serial port £2.50, both available from Economatics (www.economatics.co.uk/education)
They can be programmed using PIC AXE from (Revolution.com) or as I have done using PIC Logicator Version 2 from Economatics (Upgrade V1 – V2 for £95.00) PICAXE08M Chip has 4 ready programmed tunes handy if using it for a Christmas decoration but a piezo sounder would need to replace one of the outputs.
List of Circuit components, availability and cost (approx £3.00) Pic Project Components Order
No. Product Order code Quantity Unit Price
1a Battery Holder 18-0498 1 0.25
1b Battery 3v Lithium coin cell 18-0490 1 0.37
2 Pic Chip PICAXE08 1 1.00
3 Capacitor 100nF 10-0230 1 0.06
4a Red LED 55-1796 2 0.04
4b Orange LED 55-0124 2 0.06
4c Green LED 55-1792 2 0.04
4d Yellow LED 55-1794 1 0.04
5 22k Resistor 62-0588 1 0.01
6 10k Resistor 62-0580 1 0.01
7 Miniature PCB Switch (spdt) 76-0270 2 0.15
8 Download Socket 20-0137 1 0.08
9 PCB 305mm x 475mm 34-0176 60x50mm 0.25
10 Foamex 305 X 0.50 230mm 11 Self-Tapping Screws 2 0.04
2.89
Standard Charge For Solder, Developer, 0.11 Etchant,Electricity,ect. 3.00
All components in black Available from Rapid Electronics PICAXE CHIPS available from Economatics
Download cable £2.50 (only one needed) – will last for approx. 72 hours continual use.
Note to Teachers – part 2
Using PICAXE means that Chip can be programmed on board without taking out of circuit.
Small switch on circuit is used to switch Pin 0 between the download socket and output 0 (required during download)
When programming, set switch to socket when burning chip.
Solder holder into place without chip. Insert chip after finish soldering.
To simplify the circuit, I have used a 1.5v supply and left out the resistors.
PCB Masks for circuit included in PCB Wizz Circuit (PCB WIZARD Program needed to open them). I find if cut and pasted into another program it can affect the size.
Teachers can modify section 2 of the 2D design tutorials to specify their machines.
2D design case. Designed to be cut out on Roland CAMM2 machine using 10mm (foamed PVC, better alternative to acrylic, cheaper, less brittle and machines in a fraction of the time). Available from Technology Supplies.
Children in 2D Design tutorial told to work on A4 sheet. CAMM2 will take slightly larger (305mm x 230mm) if more space needed.
Use 3mm Foamex for the back and clear cast acrylic for the front.
Although machining parameters can be saved to set up, I have included how to set up in this section so that pupils can learn how to do this for themselves.
Holes for switch & jack plug socket can be drilled out manually or incorporated into the design Print pupils work sheets out on A4 then enlarge to A3 on photocopier.