Flow and LED deck combined?

[liebs29]

It seems like it might not be, but I cannot get heads or tails before I order. Is the flow deck and LED ring deck able to be used together?

[tobias]

Unfortunately that is not possible. It might be possible to drill a hole through the led-ring for the camera to see through or connecting a neopixel ring similar to what we once did on the CF-nano. However the light from the leds might fool the optical flow sensor when it is close to the ground though. Would be fun to test!

[kristoffer]

It is not possible out of the box, but if you are prepared to modify the LED-ring (and voiding any warranties and risk breaking it) it is. Take a look at the hack (https://www.hackster.io/krichardsson/li ... one-d050af) I wrote yesterday, it shows how it can be done.

[droneguy]

Hmm, that's very interesting! Great article!

Operationally, I have a question - the Flow deck uses the LeftExpansion7 (IO_2) pin and so does the LED Deck for the serial data for the WS2812B LEDs (labelled on the schematic as PWM_DOWN). How does that pin overloading work?

Images for reference...

Flow Deck:

LED Ring Deck:

[tobias]

In that hack I think it the front led signal line was just cut.

[droneguy]

Huh... then how does the firmware handle it?
When the drivers for the flow deck and ring deck are enabled, IO_2 is still overloaded in the firmware right?
That is, the ring deck will output a PWM on the line, and the flow deck driver will implement the RESET/MOTION logic?

[droneguy]

Nevermind.... I just saw that IO_2 is NOT used on the flow deck

Even though the schematic shows R4, R5 and R6 connected to IO_2, they are not populated on the boards.
Maybe update the schematic to reflect this?

Inkedflow_deck_400px-3_grande_LI.jpg (205.13 KiB) Viewed 5055 times

[arnaud]

The resistors to IO_2 are marked "NM" which means Not Mounted. I guess we can add some textual explanation on future schematic to mark clearly that these are intended to be not populated out of the box.