RaspberryPI IO extension


#1

Apparently they are about to launch the RaspberryPI IO extension board, that will allow to have filtered sensors and drive PWM devices (it has an atmega on it too).

Really looking forward to it, maybe using a RaspberryPI + the RaspberryPI IO extension board could save some 50USD from the overall price.

Here a teaser: http://www.raspberrypi.org/archives/1731


#2

That's great!

Got my RaspberryPI last week. Haven't powered it up though.


#3

Hi there,

are there any news concerning the Raspberry Pi in the OpenROV project?

I'm going to start with the electronics and im not shure if i should use the BeagleBone or the Raspberry Pi.

Regards

Rob


#4

So far nothing has been planned around the RPI... but the brain should work on it too (ti's just NodeJS). And the cape is basically just an arduino with some power circuits, so a version for the RPI can be done pretty easily I guess.

But if you just want to build what's already there, just but the BB :)


#5

>>if you just want to build what's already there, just but the BB :)

That is the point, i have to route the cape, i dont know if the schematic on github is in a usable state.

And I didnt test the software yet and if the soft is in the same state than the cape...

As far as i can see there is no big difference in using the RPi or the BB because there ist not so much "already there" what i can use.

Or am i wrong?

Rob


#6

If you want to solder your own board you have to do your own routing for BB or the RPI anyway. I have a BB protoboard with the electronics except for the power circuit. You can find pictures of it in the wiki and if you need help with it I can talk you through. For the BB or RPI decision: you just need a UART and a general purpose io pin for the connection between ‘the brain’ and the arduino.

For the software:we’re currently working on the node app and the arduino should be in a okay state.

Cheers Dominik


#7

Hi Dominik,

ok, i have no problem routing a board, but sometimes the informations on the openrov blog/forum/wiki are a bit confusing.

Just one example, on the cape there is no connection for a pressure sensor (depth) but the openrov command center shops depth and temperature.

So, where do i have to connect the depth sensor that the software can get the data?

For the Raspberry/Beaglebone decision, can you tell me which board is more powerful?

BeagleBone has more I/Os for shure thats a plus for it.

Also the fact that Beaglebone is longer on the market and is more prooven.

Raspberry is cheaper.

The Point is i haven't worked with those boards yet, just Atmel Microcontrollers programming in assembler and c, and of course pc programming in java, c, pascal.

So i think i will start with the beaglebone and start working with the given software.

Can you tell me what DepthSensor you are using, and how it is connected,

than i can order the parts from digikey and in the meantime im working on the cape.

Regards Robert


#8

The current version of the ROV and the software doesn’t have a depth sensor (or compass) yet. That’s to be added later.
I experimented with a pressure sensor MS5803-14B. But haven’t incorporated it fully yet. This one uses the I2C bus that you can hook up on the Arduino chip with 2 wires.