OpenRov controller board issue


#1

hi i am new to the openrov family and i have an issue with my controller board. i have v 2.6 i had the motors and the camera working until i went to put every thing in the main tube. when i was putting it in the wires on the DB-25 bridged and caused the whole thing to shut down know i no longer have the solid green and red LED's and the one blinking LED. the only LED that comes on is the green power LED and the BRX LED4 that is blinking orange. what does this mean? is my board ruined? thanks for any help given!


#2

Hi Matt:

If the Green PWR LED is on and BRX is blinking, that means that the Arduino is up and running and sending telemetry to the BeagleBone. If you don't see the three HomePlug LEDs operating (the furthest one of the left- HPWR I believe - is power to the Homeplug adapter), then there may be a problem with the Homeplug adapter, or there may be a problem with the 3.3V power supply. I'd start by removing the BeagleBone and reseating the HomePlug adapter, then making sure you insulate whatever things bridged on your DB-25 before trying to re-install it in the tube.

-W


OpenROV #439 - insert name here
#3

I have a similar problem. The only light I get on the board is the Power LED. I've bypassed my home plug Ethernet and connected directly to the beaglebone and tried swapping out the beaglebone with a new one. Still same problem. I have also rewired my DB25 connector all contact stuff checks out.

The Beaglebone boots and provides the web interface. No information at all from the board is coming through (battery V etc..).

Could it be a problem with the 3.3 or 5V from the topside adapter? Or is my controller board toast?


#4

If you removed the HomePlug adapter did you install the two jumpers to turn the power on manually? J12 & J17 on the controller board. I Installed pins in these locations and just use Jumpers that are used on computer boards to slip on the pins to jumper them. This is great for bench testing.


#5

To dig up an old thread - did you get any closure on this?

I think i have done something stupid powering the main board (2.5B ) and ‘cooked’ it resulting in the symptoms above.
BRX LED 4 blinking rapidly and Power LED on ( actually i believe its also blinking at the same speed but the off phase is very short you so can hardly see it ) - couple of times per second.
The inductor coil is also ticking at the same frequency.
The power system seems to be switching on and off rapidly judging by the above and the corresponding current draw indicated on my power supply.

so i fear that the board is ruined but i will first try over-riding the tether on/off using J12 and see if i can identify what component(s) are fried - nothing to lose !

regards
stuart


#6

So, i will update this since it may have been the same issue the OP had.

i removed the ESC’s from the board and powered it up, now i have 5V power LED on, and pulsing BRX LED , it seems to pulse gently several times per second with one more distinct pulse each second. this seems like a healthier LED sequence. wish i had paid more attention to the led sequence before the malfunction so i knew what it ‘should’ be doing!
there is no ticking, and a nice constant current is being drawn from the power supply -
0.02A @ 12 volts. does that sound correct for a working openrov board with no ancillaries connected ? ( homeplug, BBB, servo, leds, ESC all disconnected ) would be that ‘ballpark’ current for an arduino i think.
so touch wood, there may be hope yet for the openrov board.

HOWEVER my beaglebone has definitely been killed, no life at all when powered directly from USB. at least i will be able to pick one up a replacement used one cheap via ebay. it must have suffered due to the power rapidly switching on and off.

back to the ESC’s which i had removed from the main board and which i now suspect may have a part to play in this.
i made a simple test rig for the ESC’s using a servo tester and 1nr motor , testing each ESC in turn. results ESCs 1 and 3 seem to perform OK though they are not calibrated properly .
low and behold ESC2 is scrap - it makes my power supply go crazy and no response from motor - So here is the culprit i think!

outcome :- i need to replace ESC2 and find myself a cheap BBB. and…‘hopefully’…the openrov board is saved.

This has been a big set-back since the electronics were working great, but on the plus side i have learned from the mistake since i had to read the schematics properly and have certainly gained a much better understanding of the system as a result.

i will post a verdict when i get a replacement BBB

cheers
stuart


#7

Hi Stuart:

A bad (shorted) ESC will cause the set of symptoms that you originally saw with your controller board. Here’s what happens:

When you apply voltage over the ROV tether, battery power is applied to the +5V switching power supply, which turns on the Atmega 2560 (Arduino Mega) that is embedded on the controller board. After this processor boots, it flips a switch which sends battery power to the ESCs. If an ESC is shorted, it pulls down the battery voltage below ~6V, which stops the +5V switching power supply, which then stops the processor, which then opens the switch. Lather, rinse, repeat.

Unfortunately I have no idea whether your board can be salvaged by just replacing the BBB and the one ESC. I’d fix the ESC first, and if that seems to work, then install and try the new BBB.

BTW, the pulsing BRX LED is indicative of the Atmega chip sending telemetry to the BBB over a serial port, and means that the Atmega is up and running. BRX = BeagleBone receive.

Hope this helps.

-W


#8

Thanks Walt, your explanation of the power switching scenario makes sense.

i have a replacement hobbywing 18A esc ordered from hong kong
( got one of their program cards too - since it will pay dividends with configuring the ESC modes )

assuming the new ESC sorts it, i will then proceed with extreme caution and check that the 5V and 3.3V are absolutely stable before replacing the BBB, i certainly don’t wish to wreck another one.

i will update in due course.

regards
stuart


#9

well… i managed to get a replacement Beaglebone black - waited for one to come up second hand on flea-bay but they were selling for not much less than new price so i just bit the bullet & purchased new one to get things moving. i have sold some other surplus stuff so ‘swings and roundabouts’

( if anyone is looking for a BBB in UK the best price currently seems to be from CPC Farnell Ltd. its the element 14 branded item , don’t know if that makes a hoot of difference for openrov? )

With the utmost of care i flashed it with openrov image which took about 10minutes from 8gb micro SD card. And verified by connecting direct to PC with ethernet cable. all good, straight into cockpit. have they made the blue LED’s brighter on the BBB ? ive got blue spots burnt in my retinas !

Then re-fitted the BBB into my openrov board ,with homeplugs etc. i checked everything over twice with a fine tooth comb before applying power from 12v bench supply ( after previous disaster! ) And i am delighted to say that the main board seems to have survived the previous ordeal , and everything seems to be working. re-installed arduino software, LED’s, lasers, camera, & IMU all fully working with cockpit communicating perfectly over the tether.
im very relieved since i was very concerned that the openrov board itself may have been destroyed and even more worried about the possible cost of replacement!

My openrov controller board is still without ESC’s fitted since i want to be absolutely sure that all 3x work perfectly before i solder them in and risk ruining things again. Im awaiting a hobbywing program card to help with this purpose.

Once again thanks to all forum contributors and Openrov team

Stuart