Diy osd (MAX7456 version, OpenSource) - Page 118 - RC Groups
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Dec 28, 2015, 07:01 PM
Fly Hard or Fly Home!!!
VF-Alpha's Avatar
Quote:
Originally Posted by changosurf
I see. I'd probably be able to help with some of it, but unfortunately, I don't own an i2c airspeed sensor, so I wouldn't really be able to test or do much without one. I'd be flying blind

Your best bet might be to find some example code for your sensor and try loading it up on an arduino.

Also, be aware that, if you're trying to set this up on something like a minimOSD, you'll have to solder directly to the MCU pins in order to access the i2c port on the ATMega.
No I bought a board from someone ( designed by dennis) I had designed my own but that one will be done later with imu and bmp soldered directly

I do have an airspeed sensor I could mail to you.( one used on a DOSD) I was thinking of using an eagle tree airspeed sensor since they already give sample code. which i could buy one of those and mail to you. Which would probably be easier to implement.
pseudo code airspeed address is 0xEAA
----------------------------------------------------


byte data[2];
signed short reading = 0xFFFF;
i2c_start();
// select sensor in write mode
if (!(i2c_write(SENSOR_ADDRESS | I2C_WRITE_BIT)))
{
// send "read data" command to sensor
if (!i2c_write(0x07)) {
i2c_restart(); // perform I2C restart
// select sensor in read mode
if (!i2c_write(| SENSOR_ADDRESS | I2C_READ_BIT)
) {
// read two bytes of sensor data
data[0] = i2c_read(1);
data[1] = i2c_read(0);
reading = *((signed short *)(&data[0]));
}
}
}
i2c_stop();
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Apr 05, 2016, 10:36 PM
DronePlastics.com
Question, is the MinimOSD schematic open source? I see all kinds of places that make them. Wondering because I want to create some custom parts with the OSD built in.
Apr 05, 2016, 11:20 PM
Flying Wood For Fun
irun4fundotca's Avatar
its widely available, I think it is
Apr 06, 2016, 12:24 AM
Fly Hard or Fly Home!!!
VF-Alpha's Avatar
yes the minim osd is open source, even the hardware, but keep in mind the maxim chip is end of life, and will be harder to get genuine chips. i think my supplier has a mere 17 chips left. non genuine chips require some code tinkering.
Apr 06, 2016, 12:49 AM
DronePlastics.com
Ok, but where do I find the schematic from? To be clear, I'm looking to design something that would be compatible with MWOSD and/or KVOSD.

Edit: And you can buy the MAX7456s by the 1000s off of Alibaba.
Last edited by RBeaubien; Apr 06, 2016 at 12:59 AM.
Apr 06, 2016, 01:05 AM
Flying Wood For Fun
irun4fundotca's Avatar
those are clones for sure

its easy to find
https://www.google.ca/search?q=minim...w=1360&bih=651

heres a minimosd v3 that has naza inputs too
Last edited by irun4fundotca; Apr 06, 2016 at 03:11 AM.
Apr 06, 2016, 02:52 AM
Fly Hard or Fly Home!!!
VF-Alpha's Avatar
Quote:
Originally Posted by RBeaubien
Ok, but where do I find the schematic from? To be clear, I'm looking to design something that would be compatible with MWOSD and/or KVOSD.

Edit: And you can buy the MAX7456s by the 1000s off of Alibaba.
This is why I said Genuine chips. Clones are easy to find, but require some mods to the code to work sometimes, it really depends on the clone.
this is the schematic for the minim osd. it's easy to modify for more breakouts.
Apr 06, 2016, 03:25 AM
DronePlastics.com
That is exactly what I was looking for, but I don't see where you found it in that google search. I have been searching (google, bing, etc) high and low for this. Thanx.
Apr 06, 2016, 03:30 AM
DronePlastics.com
Quote:
Originally Posted by VF-Alpha
This is why I said Genuine chips. Clones are easy to find, but require some mods to the code to work sometimes, it really depends on the clone.
this is the schematic for the minim osd. it's easy to modify for more breakouts.
Sorry, missed that. Half the world is producing these things so whatever modifications that are needed can't be too difficult. My board supplier has their own version and I'm sure they will look my design over and make recommendations like they usually do so I'm not too worried. Thanks for the help guys.
Oct 27, 2016, 09:33 AM
Registered User
Hello I'm making a semi-smd version of this board. The only SMD that i will have on my board will be the max7456, I will use an arduino nano mounted on the board. When i finish it i share with you some pictures.

I have a question about the capacitors, i know that tantalium cap have longer life, could i use normal ceramic instead of them?
Oct 27, 2016, 09:58 AM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by aster94
Hello I'm making a semi-smd version of this board. The only SMD that i will have on my board will be the max7456, I will use an arduino nano mounted on the board. When i finish it i share with you some pictures.

I have a question about the capacitors, i know that tantalium cap have longer life, could i use normal ceramic instead of them?
Ceramics will work perfectly. The capacitance vs size is better for tantalum which is why you often see them used in places like this. Tantalum have higher ESR which doesn't really matter here, where you use resistors anyway to get the correct output impedance.
Oct 27, 2016, 03:09 PM
Registered User
Thank you Dennis Frie for your answer this way i had the opportunity to say thank you for all the project in "person"!

If i will manage to have my fake maxim working (discovered today) i will post a simpler version for people who are not so confident with smd soldering
Oct 27, 2016, 03:11 PM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by aster94
Thank you Dennis Frie for your answer this way i had the opportunity to say thank you for all the project in "person"!

If i will manage to have my fake maxim working (discovered today) i will post a simpler version for people who are not so confident with smd soldering
You are welcome.
There's an option in the firmware IIRC that's called something like "use slow SPI" - that will make it work with fake IC's. The original IC's handle higher datarate than specified in the datasheet - the fake ones doesn't like that :
- so just make sure you set that in the config-file and everything should work.
Oct 28, 2016, 11:52 AM
DronePlastics.com
Does anyone have any information on how to "connect" the current MinimOSD schematic to the flight controller so that BetaFlight can manage the OSD through the configurator instead of using the MWOSD configurator? Is it using I2C or SPI? I can't find any documentation on this

Thanx.
Oct 29, 2016, 02:47 AM
AKA jflyper
Quote:
Originally Posted by RBeaubien
Does anyone have any information on how to "connect" the current MinimOSD schematic to the flight controller so that BetaFlight can manage the OSD through the configurator instead of using the MWOSD configurator? Is it using I2C or SPI? I can't find any documentation on this

Thanx.
Controlling MAX and configuring various settings is very different.

If you want the FC to control OSD itself, you have to break out SPI signals from your FC and connect it to a MAX7456 BOB (break out board). If your FC has onboard flash or pads for the flash, you can break out the signals from the pads. You may have to stash your flash if SPI spec is different from that of MAX.

The MAX7456 BOB may be made from existing Minim variants, by carefully removing M328 or or cutting SPI signal traces. Instead, you can buy the BOB such the one sold by Hobbytronics (you have to mod the BOB to bring out the VSYNC instead of LOS on to the connector).

You then have to figure out what to tell your betaflight MAX driver for the connection you made. You can refer to existing FC-integrated MAX based OSD targets such as SIRINFPV, OMNIBUS and OMNIBUSF4.

If you only want to throw away the Mimim configurator such as MWOSD GUI, then there is someone working (or at least planning) on integrating MWOSD GUI's functionality into the BF configurator.

Hope this helps.
Last edited by teralift; Oct 29, 2016 at 01:45 PM.


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