Hey i got a few questions..
Is it possible to only use a raspberry pi as a controller and a internet cable to a laptop on the surface?
Is around 20 meters down a reasonable depth for the first ROV?
well, that's about what I had in mind for now. Hoping for some good answers!
Raspberry Pi only?
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KR2_Diving
- Posts: 391
- Joined: Aug 30th, 2012, 11:43 am
- Location: Currently: NW Suburbs of Chicago. Originally: NE Wisconsin
Re: Raspberry Pi only?
Hey Poken!
Welcome to the forum!
I can't comment on the RaspberryPi as I'm and Arduino man myself, but I know there are a few others on here using them.
15-20m is a pretty decent starting depth. In my very rough estimation, for every 10m depth you add, the complexity doubles. (Price also increases... Maybe not quite double.). The biggest challenge you will find as you add depth is the affect of pressure. The deeper you go, the more accurate your engineering will have to be. Especially reguarding your water tight chamber for control!
For a school project, I am guessing the budget is going to be low, so a 3 thruster arrangement may be a good place to start!
Have a dig around here on the forum and ask any questions you have!
Best of luck!
Ryan
"KR2_Diving"
Welcome to the forum!
I can't comment on the RaspberryPi as I'm and Arduino man myself, but I know there are a few others on here using them.
15-20m is a pretty decent starting depth. In my very rough estimation, for every 10m depth you add, the complexity doubles. (Price also increases... Maybe not quite double.). The biggest challenge you will find as you add depth is the affect of pressure. The deeper you go, the more accurate your engineering will have to be. Especially reguarding your water tight chamber for control!
For a school project, I am guessing the budget is going to be low, so a 3 thruster arrangement may be a good place to start!
Have a dig around here on the forum and ask any questions you have!
Best of luck!
Ryan
"KR2_Diving"
Re: Raspberry Pi only?
Hello thanks for the answers, we are probably going to get some sort of contribution. So I guess we can spend around a couple of hundered dollars on this so we got a little money to work with at least. Maybe we were going to get some kind of "sponsorship" also but we don't know yet.KR2_Diving wrote:Hey Poken!
Welcome to the forum!
I can't comment on the RaspberryPi as I'm and Arduino man myself, but I know there are a few others on here using them.
15-20m is a pretty decent starting depth. In my very rough estimation, for every 10m depth you add, the complexity doubles. (Price also increases... Maybe not quite double.). The biggest challenge you will find as you add depth is the affect of pressure. The deeper you go, the more accurate your engineering will have to be. Especially reguarding your water tight chamber for control!
For a school project, I am guessing the budget is going to be low, so a 3 thruster arrangement may be a good place to start!
Have a dig around here on the forum and ask any questions you have!
Best of luck!
Ryan
"KR2_Diving"
We are going to carry through this with precision and in detail as we got a lot of time, 100h and our freetime.(It's supposed to be done in about a year.)
I would still like to have the goal to reach 20 meters, but we'll see when we know exactly how much money we got.
Thanks for your support, looking forward to just hang around and take help from this awsome site!
See you around!
Re: Raspberry Pi only?
these guys make a raspberry pi based OpenROV: http://openrovpi242.blogspot.com (www.openrov.com) they are also doing this as a school project.
an 3-motor setup with RC car speedcontrollers and brushless motors are a fairly quick and easy way to start. there are alot of information on openrov's wiki on how to waterproof the motors etc.
http://wiki.openrov.com/index.php/Assembly
the BOM also lists some fairly cheap speedcontrollers and motors from hobbyking.
an 3-motor setup with RC car speedcontrollers and brushless motors are a fairly quick and easy way to start. there are alot of information on openrov's wiki on how to waterproof the motors etc.
http://wiki.openrov.com/index.php/Assembly
the BOM also lists some fairly cheap speedcontrollers and motors from hobbyking.
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ROVEnthusiast
- Posts: 51
- Joined: Jun 5th, 2013, 2:18 pm
- Contact:
Re: Raspberry Pi only?
One thing: with a Ethernet cable, you would need batteries on the ROV due to the power drop of 20m of 24 gauge cable. However, if you are not using batteries on the rov, you could still use a Ethernet cable but you would have to add some 16 or 18 gauge speaker wire for the power. Also, to waterproof the PI you could use a otterbox (probably a 2500 or 3500 depending on the size you need) with DIY waterproof penetrators for wires.
Re: Raspberry Pi only?
Totally late to the party 
From my experience with the Pi yes and no.
As ROVEnthusiast pointed out the ethernet cable wouldn't be able to transmit enough power to power the Pi/Motors/etc. They simply weren't designed to transmit that much power. With on board batteries it shouldn't be an issue. On the plus side that essentially covers the entire No section
There really doesn't seem to be anything holding the Pi back from being an awesome ROV controller, it's why I bought my Pi. The trouble I ran into was the limited GPIO, however I also discovered the wonder of I2C and have since slaved all the sensors and motor controls over to I2C devices. Rendering my use of the GPIO down to essentially one pin working as an interrupt that is in charge of leak detection.
From my experience with the Pi yes and no.
As ROVEnthusiast pointed out the ethernet cable wouldn't be able to transmit enough power to power the Pi/Motors/etc. They simply weren't designed to transmit that much power. With on board batteries it shouldn't be an issue. On the plus side that essentially covers the entire No section
There really doesn't seem to be anything holding the Pi back from being an awesome ROV controller, it's why I bought my Pi. The trouble I ran into was the limited GPIO, however I also discovered the wonder of I2C and have since slaved all the sensors and motor controls over to I2C devices. Rendering my use of the GPIO down to essentially one pin working as an interrupt that is in charge of leak detection.
Re: Raspberry Pi only?
Thanks for the advice with rc esc's and brushless motors, I will take a deeper look at that opportunity, the BOM for EU appears to be outdated though..fluxno wrote:these guys make a raspberry pi based OpenROV: http://openrovpi242.blogspot.com (http://www.openrov.com) they are also doing this as a school project.
an 3-motor setup with RC car speedcontrollers and brushless motors are a fairly quick and easy way to start. there are alot of information on openrov's wiki on how to waterproof the motors etc.
http://wiki.openrov.com/index.php/Assembly
the BOM also lists some fairly cheap speedcontrollers and motors from hobbyking.
I was thinking about having onboard batteries and only have a ethernet cable to a laptop. An otterbox is not a bad idea, I will look further into that option as well. Thanks for your information!ROVEnthusiast wrote:One thing: with a Ethernet cable, you would need batteries on the ROV due to the power drop of 20m of 24 gauge cable. However, if you are not using batteries on the rov, you could still use a Ethernet cable but you would have to add some 16 or 18 gauge speaker wire for the power. Also, to waterproof the PI you could use a otterbox (probably a 2500 or 3500 depending on the size you need) with DIY waterproof penetrators for wires.
Better late than never;)Zaibach wrote:Totally late to the party
From my experience with the Pi yes and no.
As ROVEnthusiast pointed out the ethernet cable wouldn't be able to transmit enough power to power the Pi/Motors/etc. They simply weren't designed to transmit that much power. With on board batteries it shouldn't be an issue. On the plus side that essentially covers the entire No section
There really doesn't seem to be anything holding the Pi back from being an awesome ROV controller, it's why I bought my Pi. The trouble I ran into was the limited GPIO, however I also discovered the wonder of I2C and have since slaved all the sensors and motor controls over to I2C devices. Rendering my use of the GPIO down to essentially one pin working as an interrupt that is in charge of leak detection.
Like I mentioned before, onboard batteries seems to be the best option.
Pardon my english but I don't really understand the phrase "On the plus side that essentially covers the entire No section"
It would be awsome to have a Pi as a controller for a ROV, I don't have much experience with I2C devices. Any pages where i can read and get information about that would be nice:)
Re: Raspberry Pi only?
sorry that was just a roundabout way of saying the only real issue I saw would have been if you were trying to transfer power over an ethernet cable.
As far as a tutorial http://www.instructables.com/id/Raspber ... 2C-Python/ seems to have some decent examples of both how to get I2C running on the Pi and some example Python code that shows how to interact with I2C sensors. I've been able to find I2C widgets to do just about everything from sensors to running servos for a pan/tilt system, even an ADC for the external pressure sensor I'm planning on using. So far I'm loving it to death, I went from stressing out over the limited GPIO to laying out an I2C backplane and I'm going to try my hand at scratch building some I2C motor controllers for the bilge pumps using some ATTinys and power mosfets. Course I have also seen I2C relay boards for sale that would probably work just as well.
The only real gripe so far is while I have been able to get the RasPi camera module to stream video it does so with ~1 second delay. Course neither my inexperience or the fact I have been streaming it over WiFi while testing are probably helping any. Right now I'm still in the really early stages of planning/building so everything seems to change on a daily basis.
Word of warning tho the GPIO and by proxy the I2C pins on the RasPi are unprotected 3.3v logic level pins. So if you are dealing with 5V I2C slaves you will need to build or buy a level shifter or the 5V I2C (or 5V anything in general) will (most likely) burn out pins on your Pi.
As far as a tutorial http://www.instructables.com/id/Raspber ... 2C-Python/ seems to have some decent examples of both how to get I2C running on the Pi and some example Python code that shows how to interact with I2C sensors. I've been able to find I2C widgets to do just about everything from sensors to running servos for a pan/tilt system, even an ADC for the external pressure sensor I'm planning on using. So far I'm loving it to death, I went from stressing out over the limited GPIO to laying out an I2C backplane and I'm going to try my hand at scratch building some I2C motor controllers for the bilge pumps using some ATTinys and power mosfets. Course I have also seen I2C relay boards for sale that would probably work just as well.
The only real gripe so far is while I have been able to get the RasPi camera module to stream video it does so with ~1 second delay. Course neither my inexperience or the fact I have been streaming it over WiFi while testing are probably helping any. Right now I'm still in the really early stages of planning/building so everything seems to change on a daily basis.
Word of warning tho the GPIO and by proxy the I2C pins on the RasPi are unprotected 3.3v logic level pins. So if you are dealing with 5V I2C slaves you will need to build or buy a level shifter or the 5V I2C (or 5V anything in general) will (most likely) burn out pins on your Pi.