After some searching and some going through the eagle files of the APM and the Oilpan, Im having a hard time finding which pins are open/available to be used at the programmers discretion. It looks like Analog0-5 is broken out on the oilpan, and An6-7 are on the expansion header. But it also seems like An15-8 arent connected to anything but a dummy header as well. Im sure not all digital pins have been used on the 1280. Is there any documentation for what pins on the 1280 are preassigned to what when using the oilpan/apm combo and what ones arent currently assigned to anything (just sitting in dummy/headers)?


Views: 1215

Reply to This

Replies to This Discussion

I can't think of anywhere other than the eagle files that this is documented at present.
I think Doug is correct but remember adding anything after the Oil pan and GPS will use up the "16 spare analog inputs (with ADC on each) and 40 digital input/outputs to add additional sensors".
I'd like to know as well for future plans (flaps, landing gear etc) but once the APM, Oil pan and GPS are all connected I can only see a few connections free (i2c, telemetry, "not GPS", pitot and relay).

Here is a picture of the IMU board with the breakouts labelled (same as underside of IMU) but dont forget things like the i2c are digital pins that you could use rather than the AN pins.
Having trouble spotting the pins under the SW1 pins? anyone know?
Not that I've ran out of pins yet :D
Just added some explanations about IMU pins on our repository..

This should clarify few issues. Number after pin name is IO pin number in Arduino.

Simply brilliant Jani but the two I'm specifically using (or will be) aren't there. Perhaps I'm being dense but I cannot find the numbers in the APM code or librarys for the i2c pin numbers. I can only see things like and compass.init even going through the library cpp Im having difficulty picking out the pin numbers.
Any ideas?
I did now include those, sure i can update picture but why would use like to use I2C pins? Is it because the connector so you could easily use cable or why??

Reason why I did not include is that you cannot use I2C pins for anything else than I2C. If you go and start using them to another things. You will mess up whole IMU due I2C is widely used on IMU board it self. For example Baro and ADC is already using it.

Just as an reference ATmega1280 I2C pins are: SDA 20, SCL 21
Hi Jani, just a minor correction...Baro is on I2C....ADC is SPI controlled like so:

External ADC ADS7844 is connected via Serial port 2 (in SPI mode)
TXD2 = MOSI = pin PH1
RXD2 = MISO = pin PH0
XCK2 = SCK = pin PH2
Chip Select pin is PC4
Ah true forget that ADC was on SPI :)
Poop thats gonna throw a spanner at the PCB :(
I have a cheap chinese camera (search eBay for "keychain camera") the two switches must be held for set time to activate features. btn1 held for on and off. btn2 held to start video, pressed to stop video and take a picture.

I had intended to add a command to the setup (eg CMD_CAMPOINT) and have it function as a waypoint but when reached (dist
As defined in the APM_RC (Servo output, pin number)

pin 11 us assigned in the APM_RC as an output but not to an output channel. Is it used somewhere else or is it a lurking digital pin?

I wonder if I can hijack pin 2 and use it for an (input) interrupt. will bad things happen if I do this?

Reply to Discussion


© 2020   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service