08m2 lookalike solar lights

Hi

Was hoping someone could help me out here, have some poorly programmed solar lights that I bought, they have a switch setting for staying on 4,6 hours or all night. The pinout is a dead ringer for 08m2, but the chip has no markings on it. The issue with the program is that when the switch setting is for 4 or 6 hours on they work fine the first night, but the second night they stay on dusk to dawn (The auto turn off after 4 hours is ignored).

So I bought a development kit for the 08m2, wrote a program and popped out the chip from the board and tried to reprogram it. No luck, did not respond to any commands. Which brings me to my three questions below.

1) Any ideas what the chip could be ? Like I said the pinout is identical to the picaxe, pin 2 was open and pin 7 was the output with pins 3,4,5,6 used as inputs. The cheapest fix would be to reprogram this chip but I am not sure what it is (A clue may be in question 2 below)...

2) The inputs for the switches are pull downs (open switch resistor to ground). When I replaced the chip with a 08m2 picaxe it read these as 0 (off) even though the pins were open. The only way I could get them to read as 1 was to add a pull up resistor to the pin. Is there a way to program the picaxe to treat an open input pin as a 1 ? (I thought the inputs should have a pull-up resistor internally ??)

3) The programming software PixAxe editor 6.7.5 has a simulate mode with a "connect to real life pixaxe" option, but when I choose it I get a message saying it is disabled for this beta release of the software. Where can I find the non beta version of the software ? On the picaxe site it does not saying anything about the software being beta or not... (I tried downloading an older version of the logicator to try to connect to the chip but it failed saying the chip was not the correct version). The reason why I wanted to connect was to monitor the inputs, I tried the datalink as well but that did not seem to be working either and does the xbee wizard do anything beyond reading in at higher and higher baud rates ? Programming the chip in the editor was a breeze and it was nice to do a software simulation of the circuit but connecting to the live HW would be even better


thanks
Nz

Hi,

Welcome to the forum. There are lots of different chips which are fitted inside DIP-8 packages! Your Solar light almost certainly doesn't use a PICaxe and probably not even a PIC. However, it might be possible to emulate the chip, but not very easily.

notzippy said:

Is there a way to program the picaxe to treat an open input pin as a 1 ? (I thought the inputs should have a pull-up resistor internally ??)

Click to expand...

Yes, that can be done, see the PULLUP command (e.g. in Manual 2). However, the pullup command cannot be used on Legs 2 or 7 of an 08M2, but the resistors do exist on the chip and can be enabled using a POKESFR command.

But the starting point must be the battery. Is it an AA style, or something different? Also what voltage does it deliver, it might be NiMH (1.2 volts) or LiFePO4 (3.2 volts), or maybe something else? That might give give us an indication how difficult the task may be. But I think you can assume that it won't be possible using (only) Logicator programming.

A few photos of the circuit board and perhaps the overall PV Cell and LEDs could be helpful.

Cheers, Alan.

1) It could be anything. None of the PICAXE software will recognise it if it is not a PICAXE and it would not likely be a PICAXE.

In fitting an 08M2, leg 2 ( Download Serial In ) will have to pulled to 0V to ensure correct operation.

2) You should be able to enable internal pull-ups with the PULLUP command.

3) The connect option is a forthcoming feature of PE6.

1. It could be one of 100's of chips. With no markings there is no way to tell. What we do know from the information you have provided is that it is not a Picaxe and cannot be programmed with the Picaxe software.

2. Since there are pull downs on the original circuit it seems obvious to me that the switch signals are active high. So reading a "0" with the switch open is what I would expect. A Picaxe or any other microcontroller can be programmed using IF statements to conditionally respond to either a high or a low. but cannot be made to read a low as a "1". In regards to pullups and features in general, you cannot make assumptions about any product. Read/search the manuals first. Pullups must be enabled in your code. See Manual 2.

3. While is is not very clear on the Picaxe Download Page, the current version of PE6 is still in "beta". There is no non-beta version of PE6. Therefore, the simulate mode with a "connect to real life pixaxe" is not available in any version (yet). You can use "debug" in your code or you can use "sertxd" in strategic places in your code to send data information to the terminal.

Hi

Thanks for the quick replies, I figured it would be a shot in the dark with what chip is this, so replacement appears to be the only option.

The batteries powering the board is three AA ,ni-mh 1.2 v. The programming I completed in basic, so far it appears to function as expected. I had to rewrite it once since I thought I could use bit operations, but apparently this chip does not support it. Not really a big deal since there are loads of room for variables. I only need pullups on c1-c4 anyways so the extra ones won't be an issue

Ill send a pic later..

thanks again
nz

Thanks for the help, was able to eliminate the pullup resistors, as promised here is a shot of the board and the rough schematic I drew from it.


Nz

What's the label on the chip? It looks like there's a label there.

bpowell said:

What's the label on the chip? It looks like there's a label there.

Click to expand...

That is the picaxe there.

Nz