openrcforums

perfect, I'll get the latest, verify it and away we go... I'll have you some in the mail tomorrow hopefully (will be a busy night )...

*YOU KNOW)... *...

We could create version 2.... - http://www.digikey.com/product-search/e ... s=620-1355

Alan

Now who wants to change things!
Quite pricey! Also, a uni directional sensor would give us better resolution.

Mike.

hehe... yeah I know... sorry, worked for too many hardware/software companies in my life I guess, can't take the *want to make more or fix out of us*... ... Just a thought...

Alan

ACS758LCB-100U-PFF-T is the uni-directional version. Runs from 3.3V as well.

Mike.

Here's my "low tech" version of your board Mike
Works perfectly, thankyou!
The striped wire will go to the +ve esc connector, with the divider resistor fitted there,
don't like megamps available at the receiver end!
Lower end 3k3 and 100nf on board.
Measures 14x20x8 mm

MikeB wrote:ACS758LCB-100U-PFF-T is the uni-directional version. Runs from 3.3V as well.

Mike.

oh no.... Question is... do you put both in the same board or do them as separate boards?

(just thinking!!!)

Oh No, not THINKING
Pin 2 is unused, and can be used as an A2D input, so we could use a single board. I think there is enough space in the flash of the 'tiny13 to handle a second A2D input and send data out the SPort.

So we could end up with a FAS100 for SPort.

Bother, now I'm THINKING

Mike.

MikeB wrote:Oh No, not THINKING
Pin 2 is unused, and can be used as an A2D input, so we could use a single board. I think there is enough space in the flash of the 'tiny13 to handle a second A2D input and send data out the SPort.

So we could end up with a FAS100 for SPort.

Bother, now I'm THINKING

Mike.

hehe... careful it's addictive!

Alan

hmm, what do you think the inferface hardware would look like?

MikeB wrote:ACS758LCB-100U-PFF-T is the uni-directional version. Runs from 3.3V as well.

Mike.

I use this 100U and the 050U with the openXvario.. both work well.
I tested it at 3.3V but the results were not very good. Not recommended. I think the datasheet say something about it..

I get them form ebay at about $8 each. Last time I got some more 050U from the same seller but a couple sensors were bad.
One had the power BATT and ESC pins reversed.. go figure.
The other was behaving like a 100B bi-directional, with 2.5V offset and the same mV/A as the 100B. It looks like they put the wrong markings on the sensor.. Bad batch I guess
But the one I have installed on my plane works very well.

João

MikeB wrote:No changes to the code. No, I haven't made a repository for it yet, need time, been doing other things!

With the 3S values, you have a resolution of around 0.05V, with the 4S values, the resolution is around 0.07V.

If you go over the reference, you just get a max. reading. If you go too far over, you will forward bias the protection diode, should be OK with enough series resistance.

What I could do is enable a pull up resistor on pin 5, then we could allow a jumper on the ISP header to pull this pin to ground. Fit the resistors for 4S.
No jumper would mean use the input as 4S.
Jumper fitted would mean scale for 3S.

This could work as we actually have a 10-bit A2D, but are really only using, for compatibility, as 8-bit. With the jumper fitted, we read the full 10-bit value, then scale it as needed (*183/133/4?) onto an 8-bit result. This way we could get the better resolution for 3S from the same resistors.

I'll see what I can do, although I have a busy weekend this weekend.

Mike.

Hey Mike, I think this is broken.

when I have 3S connected and no jumper I get the correct value displayed.

Let me tell you the setup as it's even easier than that to look at.

If I jumper 3v3 to the Ain pin, and I tell taranis that A2 should be 18.2v max, with no jumper, I see 18.2v, with a jumper I see something greater than that.

Did the math end up being the wrong direction, scaling up in stead of down?

Alan

I think you must put Taranis to A2 = 13.2 volts.

hageha wrote:I think you must put Taranis to A2 = 13.2 volts.

Ah, so having the higher resolution I need to change the scale in the taranis.... Ok, off to try that, that make sense.

Ah, ok... the interaction of the ranges in taranis vs. the values from the sensors...

All is good. changed to 13.2 in taranis (from 18.2) and with the hi-res jumper on, voltage is correct and I can see the smaller step values as it changes.

Yeah... good stuff... not how to document that feature ...

Alan

I'm confused. If you set the range for A2 to be 18.2V, it shouldn't display a value higher than that.

No jumper means the range is 0-18.2V.
Jumper means the range is 0-13.3V.

With the jumper fitted you need to ajust the A2 setting to be 13.3V (not 18.2V).

So, no jumper, A2 set to 18.2V, connect 3S, you have a reading.
With jumper, A2 set to 13.3V, connect 3S, you should get the same reading.

I just tried setting the A2 range to 18.2V, connect up with 3.3V on the AIN pin, I see 18.2V. Add the jumper, I still see 18.2V.

OK, I see you have sorted this while I was typing!

Mike.

Mike, I sent you a PM with a quick question... Thanks!
Alan

I just got my x8r a2 s-port sensor from aloft.
Wow is it small! I'll try it tomorrow.
Mike and Alan did what Frsky couldn't or wouldn't!

hehe, hey, blame it on Mike would ya ...

I should have about 60 to 100 more in a couple of weeks... would be sooner, but alas, I'm traveling... I'm also working with T9Hobby to carry them... I hope I can tell you all when that will happen too.

I heard back from Rich at T9Hobbies... As soon as I get back from this two week trip, I'll have some of these enroute to him.

More as specifics come together.

Alan

Alan, can I suggest you contact ExtremeRC in Australia (http://www.extremerc.com.au), they are a FrSky dealer. Another possibility is MultiwiiCopter (http://www.multiwiicopter.com), who also sells FrSky.

Imho wrote:Alan, can I suggest you contact ExtremeRC in Australia (http://www.extremerc.com.au), they are a FrSky dealer. Another possibility is MultiwiiCopter (http://www.multiwiicopter.com), who also sells FrSky.

Thanks all... Let me get 2 dealers handled first... i'm also working on something more akin to turnkey production... But what I can't gauge us how long of life these will be... Won't the demand all but dry up with frsky released their own version... ... inquiring minds want to know...

And thanks MikeB for all of this, I just jumped in the middle cuz I had a need too

So Mike should we just enable the extra adc pins so people can use them? How best to do the remap of the A values?

I'm thinking about it, and I'll see if I can do some code changes in the next few days.

Mike.

No hurry, I'm on holiday for a couple weeks anyway.

Thanks

Mike I'm back on Friday this week. I've hit 100 boards to build. If it makes sense to enable those other adc channels. I'd burn that firmware. Your thoughts?

Alan

aadamson wrote:Mike I'm back on Friday this week. I've hit 100 boards to build. If it makes sense to enable those other adc channels. I'd burn that firmware. Your thoughts?

Alan

Hopefully with yours and mikes help we first board owners can upgrade ours if you do upgrade the latest.

I'm not sure I'll have time, but I'll see what I might be able to do.

SM: We have the 6-pin programmer header area so re-flashing should be fairly easy.

Mike.

Good news on the header Mike. As always I'm a little programming challenged but thanks to your guidance I always do it.

I've found a few 'spare' minutes and put something together to test using a second ADC input. It seems to be working. I'm sending the raw ADC value (8-bit, 0-255 like A2) as Temperature 2 for testing. I could send the full 10 bit value.

I had trouble programming using my STK500 (with a LONG cable) set to 3.3V. I had to drop the programming frequency to 6kHz to get it to work. I'll try a short cable when I get another moment, but the long cable worked on my prototype (I may have used 5V).

The problem now is to decide what to send the value as. I could send it as A1, but this will conflict with the existing rx battery voltage. Although they have different IDs, the rx battery voltage is currently mapped to the A1 value for scaling purposes.
Another possibility is to send it as though it is the voltage from the FASV current sensor. This will have the problem that it isn't possible to scale it on the Tx to make it accurate.

For er9x/ersky9x I copied what is done on openTx, that is map the RX battery voltage to A1. Maybe this needs to be changed!

Mike.

The STK500 doesn't have high current drivers, and we have a capacitor on pin 7 of the 'tiny13. This is present for the ADC function, but the pin is also the SCK signal for programming. This is why I had to slow the programming clock down. My prototype didn't have the capacitor. Using a USBASP will probably be fine as it has a much higher drive.

Mike.