Hello,
I have a MAX7456 chip, which is a relatively simple OSD chip. It's fitted on a breakout board and you talk to it through an SPI.
I tried to find out a way to easily connect the chip on the ardupilot, but the current SPI is used I think for the ADC info (IMU).
Would it be difficult or problematic to hook up this thing on the SPI port on the APM? would you recommend it?
At the moment I resorted to the use the Xbee serial port 3, as I don't use a ground station at the moment. This serial port then talks to a smaller atmega, which interfaces with the chip. it's a heavier, more complicated solution, but is not as invasive on the board as other measures.
Any recommendations on interfacing with additional SPI devices in general?
G>
Replies
Having the ADC as the sole device on the SPI was intentional due to the critical nature of the gyro and accel sensor readings. Electrically, adding another device should not be difficult. However, you will need to be very careful about how you write the code so that you do not impact performance of the IMU.
Not sure I am supposed to talk about this, but there is a product in the works which will interface with APM and includes the MAX7456, among other things.... The dev team is testing the first run prototypes now.
I have been wondering this myself. Granted it appears that for $18 is dollars for the 7456 then if I need an arduino add another $20 plus $10 for connectors board and all the random other crap that I will find out I need as I build it could cost around $50. In my experience its good to expect to need multiples of a part when building things from scratch. I could just buy an Remzibi for cheaper and then I know it will actually work. Granted allot of fun and good learning can be had making things yourself.
Sounds like your going to just use an Atmega chip and not a full on arduino board. Only embeded dev I have done was all with a PIC so I am not sure how that would work out for me. Sorry I know this reply is not really a solution but just thought I would say that I have also thought about this option and would be interested in the solution/why it wont work also.