Power Mote from Raspberry Pi?


#1

Hi, I’m thinking about installing Mote to light up Marquee. Can I just buy a strip and power it from USB port from the Pi3?

Sorry, I haven’t started building my picade so I’m not sure how many of the USB ports are used in the build.


#2

You’ll need the Mote control board to power the Mote sticks, but this can be powered by USB although I’d be wary of the power draw on them if you are powering a Picade too. Maybe if it had a powered USB hub, then I can’t see why it wouldn’t work? Might be a bit overkill though - maybe use a Blinkt strip?


#3

How would I go about utilising Blinkt? How is it powered?

Basically, I’d like to know if I can get a light strip that constantly shines one colour (probably white) when I power up the Picade. I don’t really want to use a second power supply (My Pi 3 is powered by 1 power supply) - wonder if I could just plug something into a spare USB port on the Pi.

Thanks for the help


#4

yes, you can… Mote hooks up to USB. However, as @Mr_A pointed out, if the power draw of the whole thing outweighs your PSU, you will run into trouble.

I guess the Mote has the advantage that if you hit a wall it is specifically designed to be powered independently, if needs be. It’s also modular - up to 4x 16 pixels sticks.

On the flip side, a blinkt will draw less, not least because we’re comparing 8 pixels to 16 (minimum) in the case of Mote (although technically you could cut a Mote stick to any length if you really wanted to).

note that blinkt! hooks itself up to the Pi GPIO, so if you were looking at further GPIO based add-ons, this could also turn out not to be such a good idea, although that will be by far the cheapest option (£5 vs min £22).

If I were you I probably would go with the Blinkt in the first instance to test the water, but the installation will be a bit more fiddly.


#5

Thanks for the replies so far guys!

Yeah, I noticed Blinkt plugs into some pins(?) on a Pi is it? As my Pi will be mounted to the back of the Picade, how would I get Blinkt up in the marquee?

Apologies to all for my royal noobness 😂


#6

by hooking up 4 ‘jumper’ wires from the Pi to the back of the blinkt, as illustrated here.

like I said the installation will be more fiddly and you’ll need to find wires long enough for the desired positioning of the stick compared to the Pi.

… Mote cables on the other hand comes in length of up to 2 meters (50cm I would have thought would be more than enough), so it’s very much a plug and play experience (the software side aside).


#7

That does sound a little less plug and play for me.

In regards to Mote and its power draw, how can I calculate its power needs?

I will be using a Pi3 which will be powered by an official Raspberry Pi power supply. Then I guess I have to consider Picade’s power thirst? I haven’t a magoo when it comes to amp watt talk, sorry (embarrassed).


#8

if all you want is white LEDs, why not just use something like this? http://www.ebay.co.uk/itm/5V-30LED-USB-SMD3528-WHITE-Flexible-Light-Strip-IP65-Waterproof-Lighting-String-/152390707523?hash=item237b31a943:g:VB4AAOSwImRYdMII

Mote and Blinkt are fab, but they sound like they might be overkill for what you’re looking for?


#9

Thanks @archieroques I did go down this path. A strip of RBG LEDs which plugs into the Pi. It has brightness control (about 10 levels!) So, anything past level 2 starts to cause problems with the Pi. I have it on level 1 brightness and it’s been on for a few hours with no issues. The brightness is fine too.


#10

How are you powering them - throught the USB ports or the GPIO pins?

If over USB, you could use another power supply (like a powered USB hub) to provide separate power to go higher power if you wanted. You might be able to use [this micro USB breakout] (https://shop.pimoroni.com/products/adafruit-usb-micro-b-breakout-board) or this Sparkfun hydra power cable for no soldering to provide power to the strips if they connect to the GPIO.


#11

I have he strip plugged into a spare USB port on the Pi3. What are the benefits of using the Sparkfun instead of the method I’m using?


#12

With the method you’re using, the power is being pulled through the Raspberry Pi - so the current is limited (as I believe the Pi has current limiting on USB ports, as most PCs do (see this post for more info)) whereas if you connect it directly to the power supply, you can draw as much current as the PSU can supply without putting strain on the Pi.


#13

Yeah seems using a second power supply would be the best solution. Just thought I’d see if I do this via the Pi so I only had one psu connected. Two poorer supplies, for me, is a bit less dynamic and messy if you get my drift?