Difference between revisions of "Meggy Jr RGB FAQ"

Latest revision as of 09:14, 26 September 2014

Part of the documentation for Meggy Jr RGB.

General Questions

1. How do you turn the sound off?

Hold down any button at turn-on time. This functionality is built into the Meggy Jr library functions, so it will still be there when you write your own programs, unless you go out of your way to disable it.

2. Why is my handle set brown and papery?

Handle sets may come with protective paper or film on one or both sides. It will peel off very cleanly once you get it started.

3. Can Meggy Jr be powered from the USB-TTL connector?

Not without some hacking. Meggy Jr uses a little too much peak power to be a good USB-powered device. Hint: There's a USB 5V pin available at the USB-TTL connector.

4. Where do I put a link to my Meggy Jr RGB project? (Also, Where can I find other Meggy Jr RGB programs?)

On the Meggy Jr Projects page!

5. Why does my Meggy Jr RGB keep restarting during the startup screen?

This can happen when the batteries are low.

Assembly Questions

0. Is there a version that doesn't need to be assembled?

Yes, there is a ready-to-use version, available here.

1. Where can I download the assembly manual?

On the [Meggy Jr RGB page].

2.Help! My capacitor C3 is too big! It's tilting my LED display!

No, C3 is just barely small enough. Don't squish it or mangle it-- that can cause serious problems; it will fit in place just fine if you follow this procedure. Bend the leads and set it flush against the circuit board as described in the manual. Set the socketed LED display above it-- in the correct orientation-- so that it rests in place above the capacitor. Turn it all upside down (on a smooth surface so that you don't scuff your LED display). Some pins of the LED display socket will stick through the circuit board a little, some a lot, and the circuit board will rest at a funny angle. Now level the circuit board by hand, so that the pins all stick through the circuit board by the same amount. It isn't important that they actually stick through the board much at all-- it's okay if the pins just end up *level* with the top surface of the circuit board. Now solder one corner pin of the socketed LED display, make sure that the circuit board is still level, and then solder the opposite corner. If it looks nice and level now, go ahead and solder all the rest of the pins.

3. My second-to-bottom row of LEDs is always red.

Problems like this are usually due to an inappropriate blob of solder somewhere. (And a row of LEDs out means that you're missing a blob of solder where there's supposed to be one.) This particular error can be caused by a blob accidentally connecting pin 1 of chip U3 to a nearby hole (via) in the circuit board. Try to make a smaller blob of solder on pin 1.

Programming Questions

1. How do you get started programming Meggy Jr?

Start with our programming guide, available on the [Meggy Jr RGB page]. .

2. Why can't I program Meggy Jr?

Assuming that your hardware and software is all good, one of the less obvious things is that Meggy Jr needs to be powered on when you program it.

3. Why do I have to unplug the USB before every time programming Meggy Jr?

This can happen on Windows machines. Try adjusting your port settings to end the pain: Device Manager - Comm Ports - USB Serial Port - Port Settings - Advanced button - Set RTS On Close.

4. Can Meggies communicate over the serial port?

Yes; we even have example code showing how to do that.

5. Do I have to program Meggy Jr?

Nope. It's preprogammed. Programming is fully optional.

6. My Meggy Jr is working correctly, except the lower-left pixel is dark on the splashscreen!

No worries-- That's actually normal on some versions.