My daughter is getting ready to make improvements to her basic ROV that she built last year for science fair. We have been discussing the different stabilization packages, and are going to be ordering an electronics package from you. My question is the following;
I understand that the interface board set, and the addition of the Pi are the primary differences, but what are the additional differences in functionality? She needs to be able to control a pair of solenoid valves (or additional servos for mechanically operating valves), will both accomplish this task, or is one better than the other?
I understand that the video quality will be different as the advanced lets you stream HD while the basic does not, but is there a difference is other capabilities?
Also, next year she wants to do a robotic arm, which package would be best for this?
I understand that the interface board set, and the addition of the Pi are the primary differences, but what are the additional differences in functionality?
The “advanced” electronics uses the Raspberry Pi and HomePlug technology to send video and ROV control data through a single twisted pair of wires. The “standard” electronics sends an amplified NTSC video signal up one twisted pair and the control data up two twisted pairs using RS422.
She needs to be able to control a pair of solenoid valves (or additional servos for mechanically operating valves), will both accomplish this task, or is one better than the other?
No. Both versions of the electronics depend on ArduSub software to interface and control the Ardupilot controller. In order to control anything beyond what is already supported will require changes to the software.
I understand that the video quality will be different as the advanced lets you stream HD while the basic does not, but is there a difference is other capabilities?
The advanced electronics uses the Raspberry Pi to send HD quality video is somewhat limited in bandwidth / video lag. The standard electronics sends NTSC SD quality video with minimal lag (steady 28 fps).
Also, next year she wants to do a robotic arm, which package would be best for this?
As far as I know, neither system currently supports robotic arms, but since this is a planned feature, will probably be supported in the future.
Thank-you for your response, regarding your answer;
“No. Both versions of the electronics depend on ArduSub software to interface and control the Ardupilot controller. In order to control anything beyond what is already supported will require changes to the software.”
It seems from what I’ve read, that this is possible something that could be turned on or off from the Ground Control software(?) such as the relay or servo controls(?) Or is it much more complex than that?
No. Both versions of the electronics depend on ArduSub software to interface and control the Ardupilot controller. In order to control anything beyond what is already supported will require changes to the software.
You can probably control your solenoids with either package. The Pixhawk used in both packages can control a relay or servo-style pwm hardware. Can you show which solenoid/control hardware you want to use?
The major differences are:
Video
The basic package runs a standard definition analog video signal. The video needs to be displayed on a separate analog video monitor. Zero latency.
The advanced package runs HD video with ~200ms latency. The video can be viewed on the same computer that is being used to control the vehicle
Communication interface
The basic package communicates via RS422 serial.
The advanced package communicates via Ethernet. You can get much more data throughput here.
Regarding “You can probably control your solenoids with either package. The Pixhawk used in both packages can control a relay or servo-style pwm hardware. Can you show which solenoid/control hardware you want to use?”,
We haven’t decided exactly how we are going do do it yet, we are going to be collecting water samples, so we may do it mechanically with a pair of servos attached to ball valves, or electrically with solenoid valves, as long as we know that we can control something, when we get the ROV done, then we’ll finalize everything with the water collection.