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Old Oct 16, 2013, 06:59 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 jpahka View Post
Gotta admit I cut some corners here. I just looked where its connected in the rush-osd link below. I can use pin 25 just as well.

https://code.google.com/p/rush-osd-d.../Hardware_Mods

Summing up, the pins I thought I'd use are:

12 -> PPM
23 -> Battery Voltage
24 -> Current
25 -> RSSI
27 -> SDA
28 -> SCL

But if using other pins for battery and current is more appropriate, I'm all for it for being able to use as standard DIY-OSD as possible.

FrSky D8R-XP receiver outputs PPM from one pin, and RSSI (pwm) from another. The RSSI signal can be made analog with a resistor and a capacitor, so I'll try that.

Hmm, now looking at it, I give myself a 50/50 chance of actually pulling this off
Pins for battery-voltage, current and RSSI can be selected as you prefer (between the available DAC pins). You just have to change them in the config-file. SDA, SCL and PPM must be the exact pins
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Old Oct 27, 2013, 02:20 AM
QuaDreko pilot :)
Drekavac's Avatar
Slovenia, Kamnik
Joined Oct 2010
115 Posts
Can I upload this code https://code.google.com/p/minnazaosd/, are mappings the same?
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Old Oct 27, 2013, 09:16 AM
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Denmark, Capital Region of Denmark, Naerum
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Originally Posted by Drekavac View Post
Can I upload this code https://code.google.com/p/minnazaosd/, are mappings the same?
I can't remember the pin-config on minimosd, but if you have the source-code available, it should be a simple change if needed. It will only be volt/current pins that might differ, as the connections to MAX7456 is defined by hardware.
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Old Oct 27, 2013, 10:05 AM
QuaDreko pilot :)
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Slovenia, Kamnik
Joined Oct 2010
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Great, thank you Dennis!

It would be even better, if you add support for DJI GPS to this one.
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Old Oct 28, 2013, 07:12 PM
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Good eveing all,

It looks like we are still here in windy UK after the winds .

Anyhow, I have stumbled on this thread and I must say I’m rather intrigued. Firstly as I like to tinker with the odd PIC/MCU here and there (but by no means an expert) and I like open source.

Having looked at the project I must say I’m very impressed. My brother has been looking at the FPV scene for a while (only looking mind you because of /$$) and has been asking me about an OSD.

This looks like it will be Perfect for both his needs and also my “tinkering” hehe. I’m surprised as I was looking at something similar just using a microchip PIC (was looking at settling on the PIC16F877 if interested)

Looking through the posts and some of the code (not my strong point as I try to tinker in assembly, pain of my life but can’t bet it if you want a head ach), I like the way it’s going.

However I could not find a raw schematic as such. A few evenings, tooooo much coffee and cigarettes (yes bad for me ) I have come up with the attached. Does this look correct??



Firstly, I know that the chip shown is the ATMEGA168, but as far as I’m aware this is pin for pin compatible with the ATMEGA328P, at least it is wired in the diagram as per v1.1 of the PCB.
Secondly I have tried to label all the “headers” and corresponding MCU inputs according to again v1.1 of the PCB.


Have I made some silly mistakes (bearing in mind that I do electronics on a rather amateurish level)

Regards,

Me (darv)
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Old Oct 28, 2013, 07:24 PM
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Denmark, Capital Region of Denmark, Naerum
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I'm on my way to bed, so it will be a very quick reply...

Seriously, you just had to ask, no need to redraw everything ;-)
Please note that some components have been placed jut for footprint, like the capacitors. Some 100nF are used near chip etc.
HSYNC, VSYNC and LOS can be removed if you don't need them anyway. 4K7 in front of LED should be lower etc.



For the integrated version, please have a look here:
http://www.student.dtu.dk/~s092916/p...ntegrated.html
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Old Oct 28, 2013, 08:21 PM
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Quote:
Originally Posted by Dennis Frie View Post
I'm on my way to bed, so it will be a very quick reply...

Seriously, you just had to ask, no need to redraw everything ;-)
Please note that some components have been placed jut for footprint, like the capacitors. Some 100nF are used near chip etc.
HSYNC, VSYNC and LOS can be removed if you don't need them anyway. 4K7 in front of LED should be lower etc.



For the integrated version, please have a look here:
http://www.student.dtu.dk/~s092916/p...ntegrated.html
This is true, but I do like a challenge. However thank you very much will be interesting to see how they compare :P.

Regards,
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Old Nov 02, 2013, 11:21 AM
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I'm trying to get this code to work on the MinimOSD. These are the three steps I did:
Burn bootloader USBasp
Download Character Uploader using USBasp
Download MAX7456_OSD using USBasp

is there anything I was supposed to change in the program? I changed PAL to NTSC and some current sensor settings but that's about all I did. The ST led is blinking and the MAX7456 chip is getting a teeny bit warm, but not hot.

I didn't think burning the bootloader was necessary but did it anyways the second time I tried this, no effect.
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Old Nov 03, 2013, 11:04 AM
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Denmark, Capital Region of Denmark, Naerum
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Very small update:
http://code.google.com/p/diy-osd-max7456/downloads/list
  • Fixed problem with summary not disappearing when using "AVOID_SUMMARY_BEFORE_LAUNCH"
  • Option for integrated OSD PCB added
  • Default calibration value for voltage changed, to match exactly 5-volt reference (the old one was for use with Turnigy UBEC which is approx 5.2 Volt or so).
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Old Nov 03, 2013, 12:40 PM
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if I am using a minimOSD, what changes should I make in the code?
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Old Nov 03, 2013, 12:44 PM
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Denmark, Capital Region of Denmark, Naerum
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Quote:
Originally Posted by FPVdude View Post
if I am using a minimOSD, what changes should I make in the code?
Sorry, but I'm not really familiar with MinimOSD. As far as I know, the hardware is pretty much the same. The mentioned steps you have taken sounds right, I don't see why it shouldn't work.

I have a MinimOSD somewhere, but I have no idea where to find it..
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Old Nov 04, 2013, 03:28 PM
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Lithuania, Vilnius County, Vilnius
Joined Dec 2006
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I've ordered MinimOSD from ebay (16.80$) as I discovered that purchasing separate parts for DIY OSD will cost more than parts that allready are on MinimOSD (IC's, Crystals, caps.)
First I will try to make conversion MinimOSD to DIY OSD with Dennis Frie firmware (I hope I'll have enough guts to make it)
If failed, I'll desolder needed parts from minimOSD to make DIY OSD with Dennis PCB.

Does anyone have MinimOSD schematic?
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Old Nov 05, 2013, 03:15 PM
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Quote:
Originally Posted by FPVdude View Post
I'm trying to get this code to work on the MinimOSD. These are the three steps I did:
Burn bootloader USBasp
Download Character Uploader using USBasp
Download MAX7456_OSD using USBasp

is there anything I was supposed to change in the program? I changed PAL to NTSC and some current sensor settings but that's about all I did. The ST led is blinking and the MAX7456 chip is getting a teeny bit warm, but not hot.

I didn't think burning the bootloader was necessary but did it anyways the second time I tried this, no effect.
Hello,

I finally received a MinimOSD from a friend, and did exactly the same steps as FPVDude above. I thought I'd try the osd before soldering sensors to the pins of the Atmega 328P. And unfortunately, the result is the same, no OSD showing. Is it supposed to draw something on screen with default config, even with no sensors attached?

br, Juhis
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Old Nov 06, 2013, 01:21 PM
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Schematics:

the 7456


the 328p


I'll compare them...
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Old Nov 06, 2013, 01:36 PM
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differences that I've noticed so far:

the 7456 uses a 27mhz crystal instead of a 16mhz crystal.
The SSOSD-IN or ~CS pin from the MAX7456 goes to PD6 on the MinimOSD, but the PB2 pin on the DF-OSD.
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