ERSKYTx (was ersky9x) Questions

[cre8tiveleo]

Here is what the LCD looks like.

...

Dat's sexy, I'm throwing out the spares I have now... (not really) but that is a very nice display!


So , technically/hypothetically, if you really wanted to, you could put a touchscreen on it, use one of the serial interfaces and write code to accept the touchscreen in conjunction with , or in place of the regular push buttons...

[SkyNorth]

Yes , you could use the I2C interface and a 4 line touch panel IC ,

The problem I see, is the size of the Screen , and the size of your fingers.
Do not make for too many buttons...

There is a input connector on the board that can handle 3 extra switches.
This could be a Rotary encoder , with a push button...this would be great for Menus and as a rotary trim adjustment.....

Or you could use the 3 inputs to add some more 3 way switches.

Lots will possible with the new board....
Maybe use the Bluetooth to link to your Touchscreen phone app.

-Brent

[cre8tiveleo]

Yes , you could use the I2C interface and a 4 line touch panel IC ,

The problem I see, is the size of the Screen , and the size of your fingers.
Do not make for too many buttons... ...

Or... hmmm... c**p... now I have some ideas... will model them in lightwave tonight perhaps... muuuahahhaahahahaa...

Screen size.. no problem... just need to find the largest screen that has the proper connectors for the display driver, and voila, mod the case accordingly to fit the new touch screen... Franken 9x.

Get rid of all the sticks, trims switches, just make it one big box with a huge touch screen... totally customizable user gui. no more mode 1 2 3 or 4. you stick the sticks and trims where you want. Full colour , fpv on the controller with your control sticks... just point an away she flies... *grabs another red bull*

[SkyNorth]

This is along the idea....
http://www.rcgroups.com/forums/showthread.php?t=1411877

-Brent

[Flaps 30]

There is a 1N4002 diode as reverse polarity protection , and a 1/2 ohm resistor in the power line ... Resistor should smoke out and open if there is a reverse polarity.

One method that I have used a few times, is to put a bridge rectifier (four diode module) in the supply lines. The plus of the bridge goes to the positive rail, and the negative to the ground/zero volt line. The battery feed goes to the AC sides of the bridge. With that setup you can connect the battery any way you like and all will work. No smoking resistors or broken diodes/fuses

The downside of the above is the double diode voltage drop (app 1.2 Volts) which would mean that you couldn't use a 2s 7.4 Volt setup. You would have to use something that gave more than 9 volts to be on the safe side.

[SkyNorth]

I did look at using the Bridge...

If I drop the RTC chip , I have room for a Schottky 1A Bridge...Losses would be fairly low.
The battery would plug into the Bridge and this could supply power to the whole Radio.

It might be a better solution.

The RTC chip needs a battery backup ..witch is the internal battery....
So If you remove the battery to charge , then you loose the RTC settings.
There are chips with internal battery , but they are too expensive to use.

-Brent

[MikeB]

If you are using the main tx battery to power the RTC, then you run the risk of discharging a LIPO too low if the tx is not charged for a long time, same as leakage for a power switch. Vbat to the RTC is specified as max of 5.5V, are you supplying the full battery voltage? Would a supercap be useful?

Mike.

[SkyNorth]

If you are using the main tx battery to power the RTC, then you run the risk of discharging a LIPO too low if the tx is not charged for a long time, same as leakage for a power switch. Vbat to the RTC is specified as max of 5.5V, are you supplying the full battery voltage? Would a supercap be useful?

Mike.

You are correct , The RTC can only handle 5.5V ...so now we need a battery source.

There is no room for a supercap...

It looks like the Addition of the RTC will raise the final sales price by over $10.

I do not feel this is worth it for what it provides.

If you need time and date logging then you could enter it into the Radio , or Link up with some other Time source.

I could leave a spot on the board for the parts ...and it would be up to the end user to get and install them if desired.

Thoughts?

-Brent

[MikeB]

How about just putting the 32kHz xtal on the relevant CPU pins, then the internal RTC could be turned on. Handling the power so the CPU could be put into deepsleep mode (3uA) and keep the RTC running may be a challenge if required though.

Mike.

[SupraGo]

If the Tx can run normally without RTC and most things wouldn't need it, and if you can setup the board so the addition of an RTC module is relatively easy, then it becomes the choice of the end user to add or not, which I think ties in with the whole idea of what we are doing here.
Bill

[ReSt]

If you are using the main tx battery to power the RTC, then you run the risk of discharging a LIPO too low if the tx is not charged for a long time, same as leakage for a power switch. Vbat to the RTC is specified as max of 5.5V, are you supplying the full battery voltage? Would a supercap be useful?

Mike.

Current of a clock in sleep mode is only som uA. Probably far less than the self discharge current.

Please no chip with built in battery (except it has a pin for an external battery).
I had to throw away a motherboard, because the built in battery of the RTC chip was exhausted.


Reinhard

[SkyNorth]

How about just putting the 32kHz xtal on the relevant CPU pins, then the internal RTC could be turned on. Handling the power so the CPU could be put into deepsleep mode (3uA) and keep the RTC running may be a challenge if required though.

Mike.

It would worK ... If I use a through hole xtal..... and you dont mind that TRIM-LH-UP and SW-ELE-DR are moved to a data line (keyboard) input.

If the GPS time stamp is available could the software ware not use that to sync on?

-Brent

[SkyNorth]

If the Tx can run normally without RTC and most things wouldn't need it, and if you can setup the board so the addition of an RTC module is relatively easy, then it becomes the choice of the end user to add or not, which I think ties in with the whole idea of what we are doing here.
Bill

Yes , there is a 4 pin connector with the I2C and power signals ..this could plug into a small RTC board .

-Brent

[SkyNorth]

Please no chip with built in battery (except it has a pin for an external battery).
I had to throw away a motherboard, because the built in battery of the RTC chip was exhausted.


Reinhard[/quote]

Don't worry , no on-board battery .

-Brent

[SkyNorth]

How about just putting the 32kHz xtal on the relevant CPU pins, then the internal RTC could be turned on. Handling the power so the CPU could be put into deepsleep mode (3uA) and keep the RTC running may be a challenge if required though.

Mike.

It would worK ... If I use a through hole xtal..... and you dont mind that TRIM-LH-UP and SW-ELE-DR are moved to a data line (keyboard) input.

If the GPS time stamp is available could the software ware not use that to sync on?

-Brent

I just looked and the TRIM-LH-UP and SW-ELE-DR wont work on the keyboard input. I would have to use the extra LCD chip select and the Haptic output or
one of the external switch inputs to re-map them.

-Brent

[hdwf900]

Maybe that had been already discussed and I missed it but can you tell me if the Optex display is compatible with the original eEX9 board?

Sylvain.

[SkyNorth]

Maybe that had been already discussed and I missed it but can you tell me if the Optex display is compatible with the original eEX9 board?

Sylvain.

No its not , the ribbon cable has the contacts facing the other way.

-Brent

[hdwf900]

Too bad...
Thank you!

[Clivew]

"There is a 1N4002 diode as reverse polarity protection , and a 1/2 ohm resistor in the power line ... Resistor should smoke out
and open if there is a reverse polarity.

One worry is that some of these batteries , can deliver 100's of AMPs in a short circuit , This could vapourize the diode junction and open it , in most cases the
diode would short out, but if it opened it wont do much good.

-Brent"

What's wrong with a good old fashioned fuse instead of the 1/2 ohm (fusible?) resistor?
Just a thought,

Clive

[ScottSails]

I think it might be time to create a custom case for this board... Couple this board with say Aurora 9 gimbals and a slightly better display (looks like one picked is already much better than stock) and wow....

Scott

[SkyNorth]

The Smoking Resistor tells you something is wrong .

Also lets you measure the current draw....

I have put a couple of through hole pads next to the part , so it is easy to short / replace.

The other thing is the Fuse cost , is about $0.30 compared to $0.001 for the resistor.

It all starts to add up ...This board has over 200 parts on it !

-Brent

[wallaguest1]

will be possible to measure in mAh how much battery rest in the radio? the voltage does not return a very accurate idea, see something like 44% would be wonderful

[cre8tiveleo]

Are there specs to the optrex lcd screen?

Do your drivers support 'gray' scaling? or does xmb or ilb (which was a deluxe paint format on the Amiga, i miss the Amiga... )

cheers

[MikeB]

The LCD's are only black and white, no grey scale.

I'd wondered about monitoring the current, and then the capacity used. First we would need a current measuring circuit, then we would need to store the capacity used in the EEPROM. Unless the capacity used is stored frequently, it will not be accurate when you switch off and then on. If it is stored very frequently, the EEPROM will wear out, it is specified for 100 000 writes I think.

Mike.

[wallaguest1]

the royal evo pro does monitor the mAh, does this means this radio will not last much more than a couple of years?

what about using the microSD slot in the board for this job then? in fact that was another of my questions, what the microSD slot is for?

[SkyNorth]

People asked for SD-card support.

The first design just has a spot for a connector to access the SD -Card in SPI mode.

The Rev B, has a spot for a Micro-SD socket , and full 4 bit data line support.

There is no current use for the card...it is for future expansion.

It could hold "models" or "sounds" , or telemetry data , software updates.....

-Brent

[MikeB]

I have some ideas for trying to keep track of how long the tx has been switched on, and storing this in the EEPROM. For current measurement, the EXT2 pin is also AD8, currently unused for analog input. This could allow an addon for current measurement to be plugged in, unless Skynorth thinks he can squeeze it on the board, although we probably need to keep EXT2 free for a rotary encoder. I think keeping track of the 'on' time would be good enough.

Mike.

[SkyNorth]

Here is what I can do...

I will add a 32khz xtal to port pins.

Move trim switches to two of the EX1, EX3 port pins.

Free up EX2 for A/D use. Add a ground Sense resistor.

Move the input cap/resistors over to the Digital output connector., for Rotary encoder / external switches.....

-Brent

[MikeB]

Sounds good. Which pins will the rotary encoder option be on? I ask because I believe a timer/counter can be set up to decode this automatically.

How will the ground sense resistor work?

Mike.

[wallaguest1]

hi, this means a timer of how much time the radio was on will be used ? if so, is this a good solution? i mean... maybe someone switch a lot between modules with different output powers and consumptions, or use simulator without the module... this drains battery faster or slower, is not constant like timer is.