What is the voltage to the AxeStack?

[emuller]

Hello,
I am worried that I've roasted my brand new picaxe with too much voltage - but I have conflicting information, so I need to check.

My set up is a macbook, coupled by usb (ver 8.8) to the AxeStack. I'm using MacAxePad to program the pic.

My first question is this - what voltage do I supply to the AxeStack? In the supplied literature, it says I can apply 5-12, so I have a nice 9v pp3 battery attached to the stack. However, I read later on that I should NOT use a pp3 battery (i'm unclear if this is in referenct to the stack or the pic..) - I'm not sure if the stack has inbuilt voltage regulator or not. if not, have I done the wrong thing?

In any case, my set up appears to have died, and I don't know why, so here is the situtation.

The symptom:
it just "suddenly" dissapeared from view of the computer - i.e. Options>port>USB setup finds a usb serial connection, but here's the strange bit: in the "test" box, I can check "high", then go to mode > firmware, and macaxpad reports that it finds firmware (ver 8.8), however, if I check port>test>"disconnected", then go back to mode>firmware, it cannot find the firmware.

Now, when I try to program the pic, I am ALWAYS returned with a "hardware not found" error.

The reason this is strange, is that it WAS working a few minutes earlier - the difference is that I had a new circuit which (possibly?) fried the pic, although if it did so, it did it very quietly.

I don't want to go all the way into town to look for a new pic if I don't have to! Any clues to what is going on?

 

[Andrew Cowan]

You don't mention which AxeStack you are using.

I think the axestacks have two power pi s - one that goes through the regulator, and one that goes straight to the PIC. The PIC should be fine if you used the first. It easither sunds like a bad connection, or a dead PICAXE.

A

 

[hippy]

The AXE Stack isn't a Rev-Ed product so I'm not familiar with it but it appears to have a regulator installed and requires a 9V supply. I would recommend downloading the user manual from the manufacturer's site.

The first thing to check is that you haven't simply run the 9V battery down; try with a new 9V battery. 9V batteries are often low mAh rated so may not last all that long.

The second thing is to see if it is a previously downloaded program whch is preventing the later downloads from happening. Either press reset button and hold it until the "Connecting to hardware" message appears and only release it then, or power the unit off, leave for a while, then power it on at the same point.

The odd behaviour with MacAXEpad and the checking Firmware issue suggests to me that the power supply is problematic; selecting High allows enough current to leak into the PICAXE to get it powered enough to respond to the Firmware check which follows.

If the PICAXE is responding to a Firmware check it is probably not dead, the problem lies elsewhere.

 

[westaust55]

Suppy voltage to AXESTACK's

@emuller,

welcome to the PICAXE forum.

Seems they can accept 5 to 12Vdc

datasheets states:

Mount the ‘AXE Stack-28 onto a breadboard so that the two 2-pin strips sit in the power rails. Apply power (5 - 12 Volts DC) to the rails.

Mount the ‘AXE Stack-18 onto a breadboard so that the two 2-pin strips sit in the power rails. Apply power (5 -12 Volts DC) to the rails.

See attached pic which shows the L4931 5V Voltage Regulator which comes with the kits (U4 on the 28 kit) The 18 kit has a MIC2954 Voltage Regulator at U4.

Have you got the voltage regulator soldered the right way around. YOu will get excessive voltage if the input and output pins are swapped.

Refernece to not using 9V batter relates to Rev Ed board which (or when they) do not include a voltage regulator IC.