openrcforums

It seems to me that the topics want a bit of a sort out, otherwise there could be a lot of
brain power wasted by the talented programmers here!

Maybe it's me getting old and missing a vital point here, but it seems to me we are using a sledgehammer to crack a nut! Ok, when the board is redesigned, it might be a good idea to use a 5v switcher as the first regulator. (Though I'm not sure I like the idea of inductive motors being switched on t...

Mike, I take your point about the whole board being supplied with 3.3v, but isn't the approximate current drain predictable? Maybe with a fuse for the bluetooth module. The current drain of the audio amp and the haptic are very unpredictable, given the wide range of speakers/vibrators out there. The...

I'm using 2 x 18650 2.5 Ah li-ion batteries, alarm set at 6.5 volts and supplying the haptic and speaker from 5 volt regulator, if it shuts down, the transmitter still works. As and when I fit a bluetooth module, Brent's 100mA fuse in the supply to it idea sounds good to me! That setup isn't going t...

Mike, without your input here, software and hardware related, I for one would be totally lost! I think your approach is the right one. You have my unqualfied support for fwiw. Thanykou for all you've done and hope you will continue to do for us. It is much appreciated :) A clean slate might be nice,...

Bit the bullett tonight and modified my board for 5 volt feed to haptic and audio i/c. Used an under-board link for the haptic, so it doesn't look too untidy, just the one above board wire. It's not too bad to do, but you do need a good magnifier when isolating that via pad and removing that little ...

Clive, would you make a small schema of your solution please ? I think I will need it ... Thanks a lot! Bertrand. It's all on here Bertrand, have a look at these, Brent did it better than I could! :- http://openrcforums.com/forum/download/file.php?id=773&mode=view http://openrcforums.com/forum/...

I still want another! (I don't do pretty!)

My thoughts on this fwiw. (Correct me if I'm wrong Brent) The processor on it's own should be perfectly happy under all circumstances, with the existing 3.3 v regulator including a high voltage battery and hot conditions. The overheating of the 3.3v regulator MIGHT arise (though not in U.K.!) with h...

Think I will feed my amp and haptic from the 5 volt reg, should make it "bomb proof".
Brent, what does the pcb look like underneath that via at C61?
Could I do it on the underside to make a neat job?
Thanks

Clive

Audio i/c is 5.5v max, so can't be fed direct from the battery.
The 5v regulator only feeds the backlight as far as I can see,
so in the worst case and it shut down, you lose nothing vital!

Sorry, you're on the case already,
Should have known
That little speaker is brilliant by the way!
(No commercial interest here)

MikeB wrote:The driver chip is specified for 8 ohm speakers, so 8 ohm or higher is OK.

Mike.

I just worry about that 3.3v regulator shutting down Mike?
I wonder if there is an easy way of feeding speaker AND haptic
off 5 volt reg. If that one shuts down, you don't crash

Clive

I would think most headphone speakers would be safe as they tend to be 32 ohms. These 8 ohm speakers sound great and fit beautifully :- http://www.ebay.co.uk/itm/1-x-MINIATURE-KINGSTATE-23mm-MYLAR-SPEAKER-8-0-1W-/270547946963?pt=UK_AudioVisualElectronics_PortableAudio_MP3PlayerSpeakers&hash=item...

Sorry nope I have not done it ...but was looking at them before ...Might just get myself 2 and see :) If the don't or can't fit in the original I can always do a custom case ....They won't be wasted They're nice sticks, I have a pair here. 2 problems as I see it. 1: There doesn't seem to be enough ...

25 is the exact setting I have for my original lcd screen, just right for me
Haptic (dry joint tester) is looking promising.
Great stuff Mike!

Wow! You're not kidding "things sound much better now"!
Haptic next?
I'll put a 10 ohm in series with my 8 ohm speaker I think and
reduce the peak current a bit.
What do you do in your spare time Mike? (!)

Yes it does, I don't think haptic is implimented yet!

Just tested my DJT module to see what the safe minimum voltage is. On this one at least, it seems perfectly happy with 5.5 volts, full rf power and solid control. At 5.08 volts it stops working. So as I see it we should be fine with 2 x 18650 lithium ion batteries as the transmitter supply, with the...

You've done it Mike!
Well done indeed!
I'm happy to change a zenner if neccessary.

Clive

150 ohms Mike. Took total draw, board + DJT from 120mA to 170mA. (board + DM9 is 170mA)
The contrast issue is completely fixed, thanks!
Did think about putting a w/w pot in place of the module, and seeing what range of current
draw it would switch off over Grammar never was my strong point!

I just found a crude way of making it switch off.
I put a resistor across the supply to the DJT module.
It now draws as much current as the Spektrum DM9,
and switches off every time!
Sadly Mike the pulldown didn't do it.

Clive

Pin5 J6 sits at about 1.3v module fitted, switched off (but not off, no shutting down message)
Goes to .2v without the module, and switches off. Also switches off with spektrum module fitted.

Internally Mike.
It is odd. Just unplugged serial port, same problem. Tried V8JT module, still won't switch off
with module in place

Telemetry all working both ways, but transmitter won't switch off with the DJT module in place, wonder why?

P.S. While you're on the case Mike,
it would be nice if the backlight came on at switch on for a short while I think?

You nailed it in one!
The splash screen was disabled by default.
Turning it on solves the problem!

Clive

There seems to be a slight "funny" with the lcd contrast on mine (R39), original lcd. At switch on the contrast level is too high (vertical striations) If I go to radio setup 1 and step down to contrast setting, it jumps to the correct setting without actually changing the setting if you s...

Thanks Mike, got it! Just a quick question about frsky telemetry connection. I guess it's straight from the com1 header? I have modded my modules as you suggested with 1k8 resistors in the rxd lines instead of 2k7 as I already had a 1k in those lines on my transistor serial/ttl converters Do I need ...

It's me being stupid. I was feeding the board dc direct rather than through the back panel.
Senior moment. Trouble is they last all day now!!