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Old Nov 13, 2012, 05:30 PM
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Originally Posted by Brandigan View Post
I measured 2.49v and 1.67v for the Pro Mini and 2.31v and 1.54v for the Nano before I fritzed the Nano, as they both started with different voltages: 5.01v and 4.63v respectively.

Well, it didn't work with LV>RX0 link still connected on the v1 drone but that's not the weirdest part...
Can't say it won't in the future, as I can't get it to work with a Level Shifter on a Pro Mini at all.

I moved the Level Shifter and it's connections from the now dead - but previously working - Nano to the Pro Mini, as that's working just fine with a v1 using resistors.

Only 6 wires. Easy.

It wouldn't startup on the v1. Removed the Level Shifter again, remade with Resistors - works on the v1 again - Swapped back to Level Shifter again - checking every connection - and the Mod gets to the end with a solid Arduino LED, but with Red Motor lights every time. Telnetted in, ps and ls /tmp show no sign of at2so.arm.

That was using a 'normal' sketch without the baudrate change. So tried again with that sketch, (after resoldering everything). No change. If I leave it for a while, the Arduino light starts flashing, then ls shows the directories followed by gibberish and then it loses the connection.

Swapped back to resistors again. Tada! Works perfectly.

So I just cannot get it to work with the Level Shifter and a Pro Mini, but it works with a Pro Mini and resistors, and a Level Shifter and a Nano (or used to). When I get another Nano, I will try it with both Level Shifters and their wiring 'looms' to see what result I get, as it's perfectly possible that I've fried both Level Shifters. However if either/both work with the new Nano....

So my questions are:
1) Are these Level Shifters particularly delicate?
2) Am I frying them when soldering them (the test for this will be when I try these with the new Nano)?
3) Has anyone got either a v1 or a v2 drone with Level Shifters to work with a Pro Mini, or is everyone using a Nano?
4) If the answer to 3) is 'yes' did you have any problems and how did you solve them?
The only logical explanation I can see about level shifter and pro mini is that your level shifter is not working. Whether it is not working because you keep connecting it wrong (happens to the best of us) or because it is fried, I can't tell from what you describe. It is not incredibly delicate but it does use field effect transistors which are sensitive to static.

If you want, it is very easy to test whether it functions even with a multimeter. Connect only ground and HV to 5 V source, leave all other points unconnected to outside for now but keep whatever internal connections you use for the mod (e.g., RX_LV to LV and RX_HV to HV). Now check voltage at TX_LV and TX_HV points (they are unconnected for now, right?). You should measure +5 on TX_HV and +2.5V or +1.7V on TX_LV. Make sure you test both channels. Works so far? Now, connect TX_HV to ground. Is TX_LV at zero as well now? If so, disconnect TX_HV from ground and repeat the process for the other channel. Next, connect TX_LV to ground. Is TX_HV at zero now? Repeat for the second channel. If all eight tests are okay, the level shifter is working. If any of them are not working, you'd need to get a replacement to use it with drone.

To answer your question #3, I've had level shifter working fine with drone 1 and pro mini until I took shifter off to use for another project.
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