The green LED does more than just tell you the board is on. It is also an early warning system that you've done something horribly wrong. If you've accidentally soldered something that has created a short in the system, the green LED will not turn on, since no power can get to it. This may be the only warning you have.
You will do a power-on test at the end of every section as the first test you do. This way, if you do have a short, you will know that it is the result of something you've done during the current section, allowing you to troubleshoot it more easily.
Parts Needed
- 1 x power adapter
Instructions
When you add a component, the first thing you should do when powering on the board is watch that green LED. This will reduce the chance of something being fried on the board as a result of your mishap.
- Plug the power adapter into an available wall outlet.
- Plug the other end to the DC jack in J1.
Plug it in, plug it in. Flip the power switch to the left to turn on the board. If the light turns on, everything is good to go!
Warning If the LED doesn't come on, turn off the power immediately.
This completes the power subsystem, with the exception of the battery pack, which will be connected later.
Troubleshooting
“My Propeller isn't downloading code! Help! What do I do?!” –said everybody at some point.
It can be scary when things don't go according to plan because you have no idea why not. Here's a short checklist of things do look for when you have this terrifying moment yourself. Some of these may sound dumb, but when you don't know what's wrong, you start with the simplest answer and work your way back to more complicated ones.
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"When you trace your way back to the wall, you might find it isn't plugged in... at all..." |
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Maybe the on position isn't the side you thought it was. It's certainly happened to me. |
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Oops. You weren't looking carefully when you installed the LED, and it's actually backwards in its socket. Technically, that's OKAY! With the voltages we're operating at, the diode simply won't conduct current and won't light up; everything else will operate normally. However, without the power LED, you can't quickly determine if there is a short in your board just by turning it on. So what should you do?
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| title | Do your solder joints make good connections? |
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Solder can be tricky; sometimes, it looks like there's a connection, but it actually never got hot enough to melt all the way through.
Look over all the joints you just made. If you see some that look sketchy, try remelting them with the soldering iron, then test again. If that still doesn't work, try remelting ALL the joints, and see if that does the trick. It just might.