Replies to This Discussion

Permalink Reply by James Roney on April 1, 2012 at 10:21pm

Bump

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Permalink Reply by James Roney on April 11, 2012 at 11:02pm

Final Bump - Then purchasing APM2

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Permalink Reply by Gabriel on April 12, 2012 at 4:37am

I'll wait for the half price APM1 to appear in buy sell trade :-D

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Permalink Reply by emile on April 12, 2012 at 8:40am

"Then purchasing APM2"

That's the idea. :)

Unless you have some skills and buy this: http://www.varesano.net/blog/fabio/freeimu-v04-availability-2nd-mar...

and then modify the code to use the new sensor(s).

BTW this uses the same (almost) sensors of the new APM2 :

MPU6050 (similar to the MPU6000 but only I2C and not SPI)

MAG HMC5883L

and finally the MS5611 barometer.

If you manage to do that you will have some followers for sure.

:)

Cheers,

Emile

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Permalink Reply by emile on April 12, 2012 at 8:56am

Or this:

http://www.drotek.fr/shop/en/44-ms5611-pressure-barometric-board.html

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Permalink Reply by Frank Al on August 23, 2012 at 12:14pm

Hi Emile, thanks for the link. I ordered one, hooked it up to the I2C translator on the APM1 and made some mods to AP_Baro_MS5611.cpp to have it talk to the baro in I2C (SPI was too buggy, competing with Dataflash chip).

In APM_Config.h I added #define CONFIG_BARO     AP_BARO_MS5611

That's it! Just came back from the maiden-ms5611-flight and must admid that I'm very impressed :-)

Anyone interested in details like the code change to AP_Baro_MS5611.cpp ?

Greetings, Frank

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Permalink Reply by Teodor Yantcheff on November 26, 2012 at 5:14am

Anyone interested in details like the code change to AP_Baro_MS5611.cpp ?

Yep, me. Did you also have the magnetometer installed on the APM ? Any issues with that, taking into account that both are i2c peripherals ? Or maybe I'm reading wrong what you mean by i2c translator ? 

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Permalink Reply by Dimitri on November 26, 2012 at 7:15am

I'd be interested too.

What about the on-board sensor, does it need disabling ?

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Permalink Reply by Frank Al on November 26, 2012 at 1:59pm

Yes, I use a magnetometer too. No problems, it keeps working correctly.

Only sometimes the baro gives a false reading (very high).
These values are discarded in the changed module.

Connect the MS5611 to the levelconverter like in the pictures. If you use another breakout board then the config is:
- no pull-ups needed
- put the chip in I2C mode
- set address to 0x76 by connecting CSB to 3.3V; needed because otherwise it's the same as Bosch baro

Connect the MS5611 to GND and 3.3V from the APM.
Replace the /libraries/AP_Baro/AP_Baro_MS5611.cpp with the one attached.
Add to /ArduCopter/APM_Config.h : #define CONFIG_BARO     AP_BARO_MS5611

There is no need to disable the old Bosch baro.

Ready, don't forget to extensively test it. Let the new set standing on your bench for at least an hour, making sure the APM keeps working.

The software works up to Arducopter version 2.8.1. With every new version I check if the original cpp file has changed.
If not, there's a good change this changed version will work, but again, test it!

Have fun,

Regards, Frank

Attachments:

• AP_Baro_MS5611.cpp, 8 KB
• IMG_0982.JPG, 122 KB
• IMG_0981.JPG, 159 KB

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Permalink Reply by Dimitri on November 27, 2012 at 2:17am

Very impressive, thanks for that !

A few more questions if you dont mind:

-Why connect CSB to 3.3V ? Can't simply set address with the jumper ?

-What's a good place to get 3.3V from APM1 ?

Again, thanks for sharing ;)

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Permalink Reply by Frank Al on November 27, 2012 at 5:02am

Dimitri, you're welcome!

Connecting CSB to 3.3 is the same as using the jumper for 0x076. That remark was for users NOT using a breakout board. So: use the jumper. If you try hard you can see even it on one of the pictures (well no jumper, but solder-pad in my case).

Please view attached picture for the place to connect to 3.3V. It´s the red spot.

Attachments:

• oilpan-3v3.png, 147 KB

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Permalink Reply by Teodor Yantcheff on November 27, 2012 at 5:39am

Great ! Many thanks !

Will report progress when I have the breakout board and level shifter :)

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