Originally Posted by andreas77

It's a prototype board with the circuit for the OSD.

do u have detail on that board. the board and photos?

Originally Posted by ferdous7466

do u have detail on that board. the board and photos?

Check page 1

Originally Posted by andreas77

Thanks!

Another thing that crossed my mind.. Have you looked into the possibility of using your firmware on the SimpleOSD XL? Do you think it would be possible without major changes?

I guess that's possible if you can upload custom firmware. If it's the same guys who have made OpenLRS I guess they don't mind if we use custom firmware
But I haven't looked more at it.

Originally Posted by andreas77

Thanks!

Another thing that crossed my mind.. Have you looked into the possibility of using your firmware on the SimpleOSD XL? Do you think it would be possible without major changes?

Ok, I've looked into it a bit myself, and my first impression is that it looks doable, but it will require some changes in the code. The main difference is that SimpleOSD uses a LM1881 video sync separator that generates line and frame sync pulses to the atmega.

Here's what I've found out so far: (I might have made errors!)
- Line sync => PD2/INT0
- Frame sync => PD3/INT1
- MOSI => Pixel generation
- Current sensor bat 1 => PC4/ADC4
- Current sensor bat 2 => PC3/ADC3
- Voltage bat 1 => ADC7 (using 1/10 voltage divider?) (Not sure about this one)
- Voltage bat 2 => PC2/ADC2 (using 1/10 voltage divider?)
- RSSI => PC1/ADC1
- AN1 => PC0/ADC0
- Push button => PD6
- PD5 => Red LED
- PB2 => Audio out
- Video signal is also connected to PC5/ADC5, I wonder what this is used for?
- 14.745MHz system clock (why that odd number?)

Next question is if the bootloader it uses works with the Arduino IDE? And is really worth the effort? SimpleOSD firmware works just fine as it is..

Originally Posted by andreas77

Ok, I've looked into it a bit myself, and my first impression is that it looks doable, but it will require some changes in the code. The main difference is that SimpleOSD uses a LM1881 video sync separator that generates line and frame sync pulses to the atmega.

Here's what I've found out so far: (I might have made errors!)
- Line sync => PD2/INT0
- Frame sync => PD3/INT1
- MOSI => Pixel generation
- Current sensor bat 1 => PC4/ADC4
- Current sensor bat 2 => PC3/ADC3
- Voltage bat 1 => ADC7 (using 1/10 voltage divider?) (Not sure about this one)
- Voltage bat 2 => PC2/ADC2 (using 1/10 voltage divider?)
- RSSI => PC1/ADC1
- AN1 => PC0/ADC0
- Push button => PD6
- PD5 => Red LED
- PB2 => Audio out
- Video signal is also connected to PC5/ADC5, I wonder what this is used for?
- 14.745MHz system clock (why that odd number?)

Next question is if the bootloader it uses works with the Arduino IDE? And is really worth the effort? SimpleOSD firmware works just fine as it is..

Great info, thanks
I will probably continue to use Arduino mini/nano - as a DIY project it's fun to make some hardware as well.

But with that said, I'm i bit tempted to test it.
The code is easily changed to support SimpleOSD. Replace the analog comparator interrupt with the "new line" interrupt and just make a simple "new frame" interrupt that resets line-count. Shouldn't take long

Edit; just mailed flytron to be sure it's okay to use custom firmware

Originally Posted by Dennis Frie

Great info, thanks
I will probably continue to use Arduino mini/nano - as a DIY project it's more fun to make some hardware yourself as well. And yes, why bother if the software on SimpleOSD already works great

But with that said, I'm i bit tempted to test it
The code is easily changed to support SimpleOSD. Replace the analog comparator interrupt with the "new line" interrupt just make a simple "new frame" interrupts that resets line-count. Shouldn't take long

Just be careful, I think I just bricked mine.. The bootloader used is called Megaload, I've successfully uploaded a simple "pin toggle" program, but now the bootloader seems to be broken, can't upload code anymore.. This happened after I added a line to the code the clear the watchdog-timer (which is enabled).

Originally Posted by Dennis Frie

Edit; just mailed flytron to be sure it's okay to use custom firmware - but they seem to like open-source

I've read on their forum that they are planning to release the source code for it, so I guess it's ok.

Originally Posted by andreas77

Just be careful, I think I just bricked mine.. The bootloader used is called Megaload, I've successfully uploaded a simple "pin toggle" program, but now the bootloader seems to be broken, can't upload code anymore.. This happened after I added a line to the code the clear the watchdog-timer (which is enabled).

Hmm, sounds weird.. The bootloader should always run the first second or so. You can't upload a new bootloader with an ISP (if the pins are available)?

Originally Posted by Dennis Frie

Hmm, sounds weird.. The bootloader should always run the first second or so. You can't upload a new bootloader with an ISP (if the pins are available)?

Never mind, I was doing it the wrong way.

Lessons learned:
- Set megaload baud rate = 38400
- Remove all cables from simpleosd
- Connect serial cable and battery while pressing the button.
- Be sure not to touch anything else on the board (like the crystal) while pressing the button.

Now I have another problem, arduino's delay() routine runs ~4.5x too fast. AVR Libc routine _delay_ms() works perfect. I've defined a new board in board.txt where I set f_cpu to 14745000L, also defined F_CPU in my source code..

Any ideas?

Just talked to Melih from Flytron. The SimpleOSD seems to be a good priced finish hardware solution for this project. (You can order SimpleOSD replacement if you already have a USB -> serial converter etc)
http://flytron.com/osd-headtrackers/...osd-xl-v2.html

When I get back from holiday and have received the SimpleOSD I will make a code-version compatible with SimpleOSD

Andreas77 - Sorry, can't help you with the delays. 4.5x faster sound like a weird number

What the advantage of the SimpleOSD?
Having more pins exposed?

Originally Posted by IceWind

What the advantage of the SimpleOSD?
Having more pins exposed?

It's the same microcontroller, it shows the text the same way etc. so you should be able to do exactly the same with SimpleOSD and the hardware shown in this thread.

The only major difference is, that SimpleOSD uses a sync-seperator instead of the analog comparator.

So, it's basically a good and pretty cheap hardware solution if you don't want to make it yourself. I think it's fun to make myself - but if I need an OSD or maybe two more, I don't mind to pay a little extra for a complete hardware solution with all SMD components

Ahhh I haven't noticed it had the sync-separator.
I have some at home (LM1881) but I do prefer the ultra-simple solution like the one you've been developing. Well depending on the planned usage.
Of course it ends up having limitations but again, it's a super easy solution with a minimal parts counts
The less I have done was (ATmega88 + resistor).

Except for the few pins exposed the e-osd from HK is also a great hardware for this, I was actually planning to go for it and upgrade it's firmware.
I may had some extra wires for GPS and for a current sensor.

Originally Posted by IceWind

Ahhh I haven't noticed it had the sync-separator.
I have some at home (LM1881) but I do prefer the ultra-simple solution like the one you've been developing. Well depending on the planned usage.
Of course it ends up having limitations but again, it's a super easy solution with a minimal parts counts
The less I have done was (ATmega88 + resistor).

Except for the few pins exposed the e-osd from HK is also a great hardware for this, I was actually planning to go for it and upgrade it's firmware.
I may had some extra wires for GPS and for a current sensor.

Year, the Arduino and the analog comparator with a few components is pretty simple and works perfect. For a DIY project I also prefer the analog comparator rather than the LM1881.

No worries, I will continue with the Arduino OSD, but I will also make the few changes needed to make it compatible with SimpleOSD. Hopefully I can make the same code work on both Arduino and SimpleOSD, so you can just outcomment 2-3 lines to choose the Arduino version or SimpleOSD.

The e-osd would have been perfect if it had RX breaked out - and preferable a bit more memory.

I'm going to Zermatt in a couple of hours and will be away for 2 weeks. Hopefully I will be able to get a couple of flights and get some ground recordings when I get home.