Enabling DSHOT on Pico Blx (was: I can flash each ESC, but two motors won't spin)


#1

Eachine 4in1 Minicube ESC + Pico Blx FC on an Arfun Pro 95 frame with those clearance-sale Racerstar 1103 6500KV motors from a couple months ago.

It was looking like this, playing around with prop sizes:

Was doing an “exercise” build, practicing my build process. Got things pretty tight IMHO, but when I finally did motor tests, two motors wouldn’t spin. This was after getting all the important bits wired up and screwed on, with a couple parts of the install being permanent-minded, so tear down would be a little painful.

Got to motor testing, but two motors wouldn’t spin. Check wiring, all looks good. No obvious damage to the ESC, though some of the soldering needed a lot more heat than I preferred.

Went to BLHeli configurator and was able to flash each of the ESCs to the very latest DSHOT, so this proved that I had comms through USB on the FC to the ESC via signal wires, right? Then I need to verify pos and neg to the ESCs, right?

How would I do that? Any other suggestions for debugging this?

Here’s the ESC on first:

Here’s the FC with most of the wiring done:


#2

Problem was setting ESC protocol to DSHOT. In spite of the product being rated as such, it will only work with MULTISHOT reliably.


#3

Thus far…


#4

You might want to check the resource mapping


#5

I’m aware of resource mapping, but how are you thinking that would help? I’ll watch the video anyway, but at first glance, I’m not understanding why you’re suggesting that.

Thanks for your consideration, though! I’ll come back after watching the video.


#6

See if this helps, it looks like you are not wired for d-shot. I’ve just set up a piko blx d-shot similar to this ans it works well.


#7

I needed to bridge the CPPM/SBUS pads for CPPM to use the OrangeRx R614XN receiver. Can I bridge the SBUS pads as well in order to do this hack?

EDIT: I see that I can NOT use PPM for this hack; line one of the CLI commands. I have a choice to make.

Think I should go for DSHOT at the cost of a bigger rx?


#8

I’m just having a look but I think if you don’t use led strip you can use that instead. Not documented anywhere but I believe it’ll work.
Cli command would be;
resource LED_STRIP NONE
resource MOTOR 1 B08
save

If you’re willing to test, I’m about for another half hour.

Edit, jumper fron motor 1 signal pad to led strip pad on the front end of uart2 strip of pads.

Edit2, I think I can see an led strip in your last pic, if you want d-shot it looks like you’ll need to change something out. Also noticed you have sbus jumper soldered.


#9

Working on this now. I changed the SBUS jumper and removed the LED wiring. I’m following your last suggestion.


#10

Didn’t work with LED strip.


#11


#12

Hmm, I was quite confident there. What does your resource list look like now? Just resource list in cli.


#13
# resource list
IO
A00: BEEPER 
A01: FREE 
A02: FREE 
A03: FREE 
A04: FREE 
A05: ADC_BATT 
A06: MOTOR 2
A07: PPM 
A08: FREE 
A09: FREE 
A10: FREE 
A11: FREE 
A12: FREE 
A13: FREE 
A14: FREE 
A15: MPU_EXTI 
B00: MOTOR 3
B01: MOTOR 4
B02: FREE 
B03: FREE 
B04: FREE 
B05: LED 2
B06: FREE 
B07: FREE 
B08: MOTOR 1
B09: LED 1
B10: FREE 
B11: FREE 
B12: MPU_CS 
B13: SPI_SCK 2
B14: SPI_MISO 2
B15: SPI_MOSI 2
C13: FREE 
C14: FREE 
C15: FREE 
F00: FREE 
F01: FREE 
F03: FREE 
F04: FREE 


DMA:
DMA1 Channel 1: FREE
DMA1 Channel 2: MOTOR 3
DMA1 Channel 3: MOTOR 4
DMA1 Channel 4: FREE
DMA1 Channel 5: FREE
DMA1 Channel 6: MOTOR 2
DMA1 Channel 7: FREE
DMA2 Channel 1: ADC
DMA2 Channel 2: FREE
DMA2 Channel 3: FREE
DMA2 Channel 4: FREE
DMA2 Channel 5: FREE

#

#14

Try, set sdcard_dma = OFF
There may be a DMA conflict.


#15

CLI says “Invalid name”.


#16

I’m having issues with this OrangeRx, not sure if it’s related. I bound it prior to install, but I get no response in BetaFlight at all when plugged in via USB. When I attach a lipo the Receiver tab goes to random values over on all channels, still no response from the transmitter.


#17

Just tested pin B08 is connected to the led strip pad and pin B08 is capable of timed pwm output so it should work unless theres a conflict. Sdcard dma is off by default on 3.1.6 onwards.


#18

Well, I’m about to replace the orange with a sat rx, so I might be able to try your original idea.


#19

Never used an orange rx before always went lemon. If its like other spektrum sats then it uses 3.3v and connects to the sat port.


#20

Here’s the Orange, says it can handle broad input voltage: