How do I minimize the number of wires going through my Cat5
How do I minimize the number of wires going through my Cat5
On my control side I am going to have 3 DPDT switches, a potentiometer to control speed(is there a more efficient way to do this), lcd screen, and a 12v battery which will be converted down to 5v. The rov is going to be controlled using a Raspberry Pi with a USB camera and three Blue Robotics thrusters. How can I transfer all the different inputs over a cat5 cable to the ROV? Is there anything I can do to make my setup more efficient? How/where do I put the HDMI?
Re: How do I minimize the number of wires going through my C
Hmmm...i'm not sure how to help you, but i'll take a stab at it.
Well, the '3 DPDT switches and pot' sounds like the old, simple way of controlling an rov. If you went on eBay and bought a cheap PWM controller, then fed that through your 3 DPDT switches, then through six wires to Regular bilge pump motors, you would get 3-thruster control. The pulse-width-modulation controller would act like a rheostat to control speed without reducing torque. The last two wires could be used to transmit analog video via video baluns up to the surface. You'd need onboard batteries...the best way to power the rov anyway. Trying to power the ROV from the surface might seem simpler than charging batteries, but you end up with voltage surges/slumps when you run the power-hungry thrusters which makes the onboard R Pi crash/ cameras send bad video signal/ etc.
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But you said 'using a raspberry pi onboard the rov to control thrusters'. That means you have a fantastic 'computer' onboard the rov to do all kinds of things. You just need to control IT.
My way of controlling my ROV is more complicated but gives me fantastic control. And it's very similar to how the big boys do it.
I have a 32-channel ADC (analog-to-digital) converter connected to my topside Pi3 (because the Raspberry pi doesn't have analog inputs), then via the Pi3's ethernet port i connect to an ethernet switch, then to a used DSL router, which connects via my 2-wire tether (14awg stranded speaker wire) down to the second used DSL router in the ROV. Then that router is connected to another ethernet switch, then to the ROV's Pi3, which is connected via I2C to an SSC-32 servo-controller, which controls all my LED lights, ballast, buoyancy control, manipulator arms, etc. The Pi3 is separately connected to a Pixhawk flight controller reflashed with Ardusub firmware, that controls my thrusters. The reason i have the ethernet switch onboard the ROV is because i have an 8-camera security-system DVR connected to 8 onboard cameras, which sends all 8 video feeds over the internet link to topside.
Doing it this way allows me to have EIGHT video feeds, an autopilot-controlled ROV, and 32 separate functions via just two wires to the surface. Instead of trying to figure out how to control my ROV via only eight wire Cat5, i actually have plenty of spare functions i can take advantage of.
If you have any more questions or want to clarify what you are doing/hardware/funds, just ask.
Well, the '3 DPDT switches and pot' sounds like the old, simple way of controlling an rov. If you went on eBay and bought a cheap PWM controller, then fed that through your 3 DPDT switches, then through six wires to Regular bilge pump motors, you would get 3-thruster control. The pulse-width-modulation controller would act like a rheostat to control speed without reducing torque. The last two wires could be used to transmit analog video via video baluns up to the surface. You'd need onboard batteries...the best way to power the rov anyway. Trying to power the ROV from the surface might seem simpler than charging batteries, but you end up with voltage surges/slumps when you run the power-hungry thrusters which makes the onboard R Pi crash/ cameras send bad video signal/ etc.
+++++++++++++++++++++++++++++++++
But you said 'using a raspberry pi onboard the rov to control thrusters'. That means you have a fantastic 'computer' onboard the rov to do all kinds of things. You just need to control IT.
My way of controlling my ROV is more complicated but gives me fantastic control. And it's very similar to how the big boys do it.
I have a 32-channel ADC (analog-to-digital) converter connected to my topside Pi3 (because the Raspberry pi doesn't have analog inputs), then via the Pi3's ethernet port i connect to an ethernet switch, then to a used DSL router, which connects via my 2-wire tether (14awg stranded speaker wire) down to the second used DSL router in the ROV. Then that router is connected to another ethernet switch, then to the ROV's Pi3, which is connected via I2C to an SSC-32 servo-controller, which controls all my LED lights, ballast, buoyancy control, manipulator arms, etc. The Pi3 is separately connected to a Pixhawk flight controller reflashed with Ardusub firmware, that controls my thrusters. The reason i have the ethernet switch onboard the ROV is because i have an 8-camera security-system DVR connected to 8 onboard cameras, which sends all 8 video feeds over the internet link to topside.
Doing it this way allows me to have EIGHT video feeds, an autopilot-controlled ROV, and 32 separate functions via just two wires to the surface. Instead of trying to figure out how to control my ROV via only eight wire Cat5, i actually have plenty of spare functions i can take advantage of.
If you have any more questions or want to clarify what you are doing/hardware/funds, just ask.
Re: How do I minimize the number of wires going through my C
Oops! I forgot about another way to do it.
Some older RC radio Tx/Rx sets had what's called DSC (direct servo control). Basically you could plug a cord into the Tx and the Rx, bypassing the RF radio. Moving the joysticks on the Tx would control the servos/esc's plugged into the Rx without transmitting any signal over the airwaves. This allowed you to test your servos/motor on your airplane at a flying field back in the days when there were limited channels available (before 2.4Ghz), without transmitting RF and possibly crashing some other guy's expensive plane.
People have used DSC to control their ROV over several hundred feet of Cat5 via just two wires. If you need more functions than the Tx has channels, use another Tx/Rx pair. Since everyone has gone to 2.4Ghz, the old radios are available cheap on eBay/ Craigslist/ garage sales. You'd still want to have onboard batteries and want to use one twisted pair with video baluns on each end to send clean video topside from an analog camera such as this...
https://www.banggood.com/Eachine-1000TV ... rehouse=CN
Thread on here explaining DSC...
viewtopic.php?t=532
Some older RC radio Tx/Rx sets had what's called DSC (direct servo control). Basically you could plug a cord into the Tx and the Rx, bypassing the RF radio. Moving the joysticks on the Tx would control the servos/esc's plugged into the Rx without transmitting any signal over the airwaves. This allowed you to test your servos/motor on your airplane at a flying field back in the days when there were limited channels available (before 2.4Ghz), without transmitting RF and possibly crashing some other guy's expensive plane.
People have used DSC to control their ROV over several hundred feet of Cat5 via just two wires. If you need more functions than the Tx has channels, use another Tx/Rx pair. Since everyone has gone to 2.4Ghz, the old radios are available cheap on eBay/ Craigslist/ garage sales. You'd still want to have onboard batteries and want to use one twisted pair with video baluns on each end to send clean video topside from an analog camera such as this...
https://www.banggood.com/Eachine-1000TV ... rehouse=CN
Thread on here explaining DSC...
viewtopic.php?t=532