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PICAXE-08 ALARM PROJECT
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© copyright 2002 - AXE102 Alarm Student Project Notes Version 1.1
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Supported by:
Testing your circuit.
Step 1 – Check the solder joints.
Check that all the joints are connected to both the pad and the wire, and that the wire is
held firmly so that it does not ‘wobble’ when pulled. Also check that the solder does not
accidentally bridge between two pads. This is most likely to happen on the LED and on
the piezo. On the stereo socket the two square pads close together on each side can be
joined as they are already joined by a track on the board. However they must not be
joined to the central round hole.
Step 2 - Check the components.
1) Check that the black battery clip wire is in the hole marked ‘0V’ and the red battery
clip wire is in the hole marked ‘V+’
2) Check that the PICAXE-08 chip is in the socket correctly, with the dent (showing
pin1) closest to the stereo socket.
3) Check that the flat edge of the LED is connected to the correct hole on the PCB.
4) Make sure you have not forgotten the wire link over the holes marked PX at the
bottom left of the board.
5) Make sure the brass side of the piezo is stuck down with a sticky pad.
6) Check that the socket is correctly soldered, including the middle square pad which is
often forgotten by mistake.
Step 3 - Connect the battery.
Check the 3 AA batteries are in the battery box correctly. Connect the battery box to the
battery snap and put your finger on the PICAXE chip. If it starts to get hot remove the
battery box immediately as there is a problem – most likely that the chip or the battery
snap wires are around the wrong way.