Hello, I have two issues with my Peggy 2. I read the instructions and followed what I thought was good advice by mounting the LEDs on the back side of the board. Unfortunately the TONS of sketches available will not work (well... they work... but backwards). Does anyone have a simple means of reversing what is displayed? Also why does the right two thirds of LED's flicker (they are on slightly when they are not supposed to be on?). I tried the POTS but they only control the intensity of the on-state and do not reduce or eliminate the partial on status. Can't seem to find anything related to these two issues. P.S. If anyone else has a reversed Peggy 2.0 - I have a nice 5x7 alphabet in upper and lower case letters plus numbers I can share.

Hello, I have two issues with my Peggy 2. I read the instructions and followed what I thought was good advice by mounting the LEDs on the back side of the board. Unfortunately the TONS of sketches available will not work (well... they work... but backwards). Does anyone have a simple means of reversing what is displayed?

There are simple ways, and then there are efficient ways. What's best depends on what you really want to do, and how you're programming it. Most of the programs that people run aren't very direction sensitive, so this doesn't actually come up much.

The "simple" way would be to reverse the order of the bits sent out every time that you refresh the screen. But this would be very slow, and would severely affect performance. A better solution would be to modify the routines that *write* to the buffer-- for example SetPoint (very easy to change) and WriteRow (manually reversing the 25 bits).

If you're working with simple example programs, you may also be able to just leave the library alone and just alter the programs.

Again, the "right" solution for you will depend on what you're ultimately going to do with the Peggy.

Also why does the right two thirds of LED's flicker (they are on slightly when they are not supposed to be on?). I tried the POTS but they only control the intensity of the on-state and do not reduce or eliminate the partial on status.

That sounds like a hardware issue. Likely a loose LED driver chip in the socket, or a bad connection on one of its support components (capacitor/ resistor).

Windell - it is so awesome that you continue to support this thread and answer questions. Thank you.

With regard to altering programs I was looking at the PeggyWrite library... my 'alphabet' is much less efficient because I am literally mapping the entire character off of a single point. The Peggywrite library, which I do not fully understand HAS to be more efficient. I tried some manual edits to the PeggyWriter.CPP file and got ONE of the characters to reverse... but it would have taken forever unless I wrote ANOTHER program to automate it... and none of the "shapes" are commented so you have no idea what you are editing without trial and error.

Thanks again though for the advice.

Also - I will check the hardware. I soldered it up in one day... and only had two leds that needed to be re-soldered. I never did re-check my other joints OR look at the polarity of the capacitors - but that is pretty 2nd nature to me at this point and I would be very surprised if and of the barrels are reversed. Perhaps I didn't realize that some of the smaller ceramic capacitors were polarized.

I was looking at the PeggyWrite library... my 'alphabet' is much less efficient because I am literally mapping the entire character off of a single point. The Peggywrite library, which I do not fully understand HAS to be more efficient.

I haven't really looked at that library, and I don't know how efficient it is. In any case, by "efficiency," I was referring to the actual drawing-to-the-screen part of the program. It's ideal if the reversal can happen at the stage of filling the "video buffer" rather than at the stage of writing that "video buffer" to the screen.

So, if there's a place in that library where it uses a function like "SetPoint(x, y)" , you could easily replace that by "SetPoint(25 - x, y)", to reverse where each point is drawn on the screen. That's straightforward and efficient.

I never did re-check my other joints OR look at the polarity of the capacitors - but that is pretty 2nd nature to me at this point and I would be very surprised if and of the barrels are reversed. Perhaps I didn't realize that some of the smaller ceramic capacitors were polarized.

Only the big capacitors are polarized. A flaky solder connection or poor seating of a chip in the socket is a likely explanation. Could also be that one of the small caps was damaged during installation; they can sometimes crack if stressed mechanically.