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Old Jun 25, 2012, 09:48 AM
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Great project Dennis - I have been playing around on a breadboard and got the basic OSD working just fine.

Quick question about the current sensor - I'm trying to use an acs758 BI 100A but am having a few issues. Does anyone have working values for CF and RF on the attached schematic?
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Old Jun 25, 2012, 09:52 AM
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Dennis Frie's Avatar
Denmark, Capital Region of Denmark, Naerum
Joined Feb 2011
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Quote:
Originally Posted by Jack_LaLanne View Post
Great project Dennis!
Did you put the code / design under a license ? If not I would propose to use MIT as it allows use in commerical products.
No I haven't released it under any license - but written in post #1 that it can be used for all purposes. To be honest, I just like that my work is being used, I don't really care if it's copied, being used in commercial products etc. Actually, that's just neat

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Originally Posted by Jack_LaLanne View Post
Is there are part list somewhere despite the circruit scheme in post one ?
No, there is not a complete list anywhere, but it should be pretty straight forward with the few components used in the schematic.

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Originally Posted by ary View Post
Dennis, could you give us an advance on what you are working?
I really appreciate people that make open source projects
OpenSource headtracker and some PPM. I have started a topic - but not had the time to draw the simple schematic etc.
http://www.rcgroups.com/forums/showt...0#post21974530

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Originally Posted by ary View Post
How can I add the second voltimeter. What does the number above "mah" indicate? In my OSD it is all the time in 0.
The RSSI is actually just another voltmeter. You can use that or copy-paste the code used and add another analog-read.

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Originally Posted by LKJ View Post
Lok post 1785 one page back.

I think/hope i wil be one of the beta testers.

Lars.
You sure will. A test-version was shipped to you earlier today
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Old Jun 25, 2012, 09:54 AM
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Quote:
Originally Posted by dyarrow View Post
Great project Dennis - I have been playing around on a breadboard and got the basic OSD working just fine.

Quick question about the current sensor - I'm trying to use an acs758 BI 100A but am having a few issues. Does anyone have working values for CF and RF on the attached schematic?
If that's an Allegro - they don't like capacitive load. To get a descent low-pass filter you need a small cap and large resistor (as far as I remember). Two sec, will just find some info from earlier tests.
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Old Jun 25, 2012, 09:59 AM
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This is the current-ripple I had:
http://www.rcgroups.com/forums/showp...4&postcount=51
(Apparently a lot of spell/gramma mistakes in that post, I must have been drunk that day)

According to the datasheet max 10 nF load and minimum 4.7K ohm load.
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Old Jun 29, 2012, 06:02 AM
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Hi Dennis,

Thanks very much for the replies - I'm still working on the current sensor

GPS is next - I'm hoping to make use of this unit: http://www.pvelectronics.co.uk/index...products_id=65
It's the same unit flytron seem to use but it's available to me in the UK.
Unfortunately it's limited to 4800bps - I read further back in the thread that 5Hz probably wont work at 4800bps. Will I be limited to 1Hz?
Is there really much difference in GPS performance between 1Hz and 5Hz?

Anyone know how to change the firmware on the PA6B GPS?
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Old Jun 29, 2012, 06:09 AM
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Quote:
Originally Posted by dyarrow View Post
Hi Dennis,

Thanks very much for the replies - I'm still working on the current sensor

GPS is next - I'm hoping to make use of this unit: http://www.pvelectronics.co.uk/index...products_id=65
It's the same unit flytron seem to use but it's available to me in the UK.
Unfortunately it's limited to 4800bps - I read further back in the thread that 5Hz probably wont work at 4800bps. Will I be limited to 1Hz?
Is there really much difference in GPS performance between 1Hz and 5Hz?

Anyone know how to change the firmware on the PA6B GPS?
It says: "Max update rate, 10 Hz". 10 Hz is not possible with 4800 baud, so you just have to change baudrate settings and increase the update-rate to 5 hz.

For this project I'll suggest 5 hz and 9600 baud, as that's what I have been testing with.
You have to see the datasheet/command data to get the commands for changing baud-speed. Can't remember them.
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Old Jun 29, 2012, 06:13 AM
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Italy
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Quote:
Originally Posted by dyarrow View Post
Hi Dennis,

Thanks very much for the replies - I'm still working on the current sensor

GPS is next - I'm hoping to make use of this unit: http://www.pvelectronics.co.uk/index...products_id=65
It's the same unit flytron seem to use but it's available to me in the UK.
Unfortunately it's limited to 4800bps - I read further back in the thread that 5Hz probably wont work at 4800bps. Will I be limited to 1Hz?
Is there really much difference in GPS performance between 1Hz and 5Hz?

Anyone know how to change the firmware on the PA6B GPS?
I beleive the descripition is wrong, 4800 is the default speed, you can change it till 115200, I have the same and I can confirm it
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Old Jun 29, 2012, 07:14 AM
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Oh cool, many thanks. Their description about the baud rate is a bit confusing.

At that price it's definitely worth a try!
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Old Jun 29, 2012, 10:57 AM
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Quote:
Originally Posted by dyarrow View Post
Oh cool, many thanks. Their description about the baud rate is a bit confusing.

At that price it's definitely worth a try!
the gps can be powered by 5v, and from about 2.5 to about 3.7 volts need to be applied on the VBACKUP pin or the gps will not boot...
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Old Jul 01, 2012, 06:38 PM
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Just an FYI for anyone trying to use it on NTSC and not being able to see the bottom line (current, voltage and MAH). After building the OSD in a breadboard in 15 minutes, and spending the next hour trying to get the bottom line to show, I followed ary suggestion from a few pages back in the thread and changed line 154, where it says "video_system" in lowercase to "VIDEO_SYSTEM" in uppercase and the bottom line started showing.

Amazing how simple it is to build and how good it looks. Thanks Dennis for all your effort!
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Old Jul 02, 2012, 12:16 PM
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Originally Posted by OrlandoP View Post
Just an FYI for anyone trying to use it on NTSC and not being able to see the bottom line (current, voltage and MAH). After building the OSD in a breadboard in 15 minutes, and spending the next hour trying to get the bottom line to show, I followed ary suggestion from a few pages back in the thread and changed line 154, where it says "video_system" in lowercase to "VIDEO_SYSTEM" in uppercase and the bottom line started showing.

Amazing how simple it is to build and how good it looks. Thanks Dennis for all your effort!
I suppose the NTSC problem is my fault - you are not the first one mentioning it. sorry guys

Glad you guys can help each other when I'm busy with other things
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Old Jul 03, 2012, 03:56 PM
ary
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Quote:
Originally Posted by OrlandoP View Post
Just an FYI for anyone trying to use it on NTSC and not being able to see the bottom line (current, voltage and MAH). After building the OSD in a breadboard in 15 minutes, and spending the next hour trying to get the bottom line to show, I followed ary suggestion from a few pages back in the thread and changed line 154, where it says "video_system" in lowercase to "VIDEO_SYSTEM" in uppercase and the bottom line started showing.

Amazing how simple it is to build and how good it looks. Thanks Dennis for all your effort!
Are you using Linux to compile it? I had this problem on Linux but I didn't try it on Windows.

Warm regards!
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Old Jul 03, 2012, 04:13 PM
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Originally Posted by ary View Post
Are you using Linux to compile it? I had this problem on Linux but I didn't try it on Windows.

Warm regards!
I'm using Mac OS 10.7. After changing that it works like a charm.
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Old Jul 05, 2012, 10:35 AM
ary
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Originally Posted by OrlandoP View Post
I'm using Mac OS 10.7. After changing that it works like a charm.
Mac OS is case sensitive too but i don't know if it has any relation with that
Regards.
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Old Jul 07, 2012, 03:21 PM
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Joined Mar 2005
287 Posts
Will this schematic work with a ceramic resonator, which i guess has a tolerance of 0.3% or so, without any problems or am i forced to use a crystal?
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