The Sumo Submarine

[Aphromann]

I am still an amature when it comes to microcontrollers, and have very little experience with C and SBasic. I have a submarine that has great moneuverability and depth, but the places I intend on taking it are tedious to drive the submarine. Its primary function will be to collect data on corries within Indiana, and the various marine life within them. Its secondary function is to act as an active fisherman, with an electroinc reel mounted on a variable x,z and y axises, (there is already a 50 lb carp I would like to fight). As such, I would like to invest in a 'insurance' system, that would allow the submarine to control when the sensors show that it has lost a signal, or has become stuck. The RC has a range of roughly 800ft in clear water, and even less for places where mud is a problem. The microcontroller I seek only needs to fill the following tasks, interpret sensor inputs from 1 sonar range, 1 accelerometer (three axises), and an array of four collision detectors (groups of five pressure sensors). To make the purpose of the submarine more beneficial, I intend to use it to collect data on water currents and temperature varriances, which do not require interpretation, but will have to be stored on a flash memory card.

To aide in its scientific purpose, I am planning on mounting a 3cm camera to the nose of the submarine, on a fixed axis, and require a method to store the video to a flash card, or telephone via bluetooth technology. (I have thought about purchasing the video transmitter and reciever, but its range seemed limited only to air transmissions, and have no idea what its range would be in water, as it is using light, not sound.) If there are any suggestions for what type of microcontroller to use, and any other aspects that were not thought of, please let me know. All equipment above has been found on the basicstamp website, basicx website and micro-cameras. The microcontroller will not have to interact with the RC beyond signal confirmation, and emergency override.

Any help would be greatly appreciated, and would help make a purposeful 'bot' to search for marine life. Thank you ahead of time.

 

[dknguyen]

My hand is cut and i am at work eating with the other hand so i wont say too much or type well. You need gyros/accelerometer so you robot knows which directin it is moving in.

 

[Aphromann]

Would you suggest a "perimeter?" using IFR or ULF transmitters?

 

[freeskier89]

The main problem I see is the camera. Really, there is not a feasible way of taking video with a MCU and storing it on a flash card. First of all, you would need a huge amount of RAM. Pipeing the data from the video camera directly to the flash card would not work at all because the camera is outputing a stream of data that is much faster than what a flash card (and MCU) can handle. I would really recommend just buying a premade solution like a normal consumer video camera or something similar rather than making your own circuitry. If you really wanted to do it yourself, I would recommend looking into some cellphone processors(this might not be the right term)...crap... I was looking into them just the other day, but I cannot seem to find links to them now.

Also... to get a video stream back to a laptop or whatever, you would have to have it be wired. As far as I know, there is no way to send that much data that fast in water.

 

[Aphromann]

Thank you for your reply. However, the original reasonig for using a 3 cm camera, was because of space on the submarine. The camera already has a RCA output, including optional audio (not necessary for this project). So I might look for a very light-weight alternative to the digital recorder, and use a hybrid Mini DV (Digital Video Cassette, DVC) recorder. It only has to be for video, since sound in water is too much to filter sometimes (wind, rocks bubbles, ambiences are a problem). One of these DVC's could hold up to 60 minutes, and the recorders have an output input device for video transfer to Macs, PCs, or VHS. I'll get back to you on the recorder.

 

[freeskier89]

Oh ok, That sounds like it should work. For some reason I thought for a moment that you were going to try to design the video system yourself! Good thing your not.

 

[Aphromann]

Yeah, the DVC recorders are decently priced, and can come as small as 10oz; which only means that I have to allocate my ballasts properly. Looks like it wont be finished in time to do a test run until next spring; mostly because the water is not recieving enough light in the waters we wont to look in. Also, could I scavange a Casio color graphing calculator to help my sumo sub out? I mainly need two EPROMS for two seperate instructions, to override the manual controls at any moment, based on seperate and elaborate variables; what chipset would anyone recommend?

 

[Oznog]

Talking to the memory card is not hard, many people have done this. You can get an SD/MMC socket for like $1 and SD/MMC cards have a SPI port which is easy to for a uC to talk to. You may want a hardware SPI but it's easy to bit-bang too.

These cards are 3.3v and do not tolerate 5v. You will either need a level converter OR use Vdd=3.3v all the way around. They also require a 512 byte buffer and a lot of earlier PICs didn't have that. BTW, dsPIC33F series is a 3.3v series (can't use Vdd=5v in fact) that is really fast and powerful. dsPIC33F is a extraordinarily capable general purpose processor, its DSP functions are actually very useful in everyday apps too.

 

[Aphromann]

COuld I simply use a SDRAM 500 mg with the dsPIC33F, or would that take a lot more work than the cheaper and better item? Thank you for the advice, Im looking into the processor right now.