Power Supplies for Propeller PCBs (and others) - use a Phone or Camera 5V supply

Cluso99

These days, 5V supplies/chargers for cameras, phones, iPods, etc·are now common-place.

So, I was thinking...
Instead of using a 6-9V power-pack with a power supply on the Prop PCB and regulating it to +5V (when 5V is required) and then to +3V3, why not use one of these supplies to get the 5V. This way we can use one of these 5V power packs (we must ensure it is regulated to 5V - I just checked the Nokia N95 supply which uses a miniature round connector and it outputs 5.95V unloaded). As an alternative, we·can also use a spare USB port on the PC (via a cable)·or a Cigarette Lighter USB charger/adapter in the car (once again need to verify it is regulated to·5V). These items are now common-place and probably most of you have one or more in your kit already.

To do this, we have a few options to get 5V to the prop pcb...

• Use the existing 2.1mm pcb connector we mostly use already and make a conversion cable (e.g. 2.1mm plug to USB male)
• Use a USB B?·socket on the Propeller PCB (cable is a USB extension cable if type B or USB host to host cable if type A)
• Use a mini-USB B or AB on the Propeller PCB (you probably have a mini-USB cable to USB host from a camera or phone in your kit)

I am considering using a mini-USB AB connector on my new Propeller·PCBs to bring in the 5V.

Why have I chosen the mini-USB AB connector...

• Adapter cables for cameras and phones to the PC USB are readily available if you don't have one or more already.
• The AB is so I can use the connector elsewhere to provide either a slave or a host using the recent USB Object.
• A pair of series resistors and I should be able to use the USB object to communicate to my PC over the same connector.

One word of caution... USB hosts are limited in how much current they can supply. My Propeller PCBs (for now at least) are way under the limitation.

What do you think? Any unforseen problems?

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
· Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz

Beau Schwabe

Cluso99,

I do this all of the time ... at least for the 5V. Instead of a plug, I usually just connect a small piece of #22 gauge wire to each stranded end, and then wrap electrical tape around that connection. I denote my positive lead by tying a knot in it. <- ya I know high tech

I have tried a few different brands.... The Motorola that I have puts out 5V @ 550mA, The Nokia works but it doesn't have any marks to indicate what it puts out, other than testing it with a meter to me at 5V.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Sal Ammoniac

That's exactly what I power my ARM boards with: surplus Blackberry chargers plugged into the board's mini-USB connector.

Coley

@cluso99

I'm thinking along the same lines, currently I am powering my HybridX3 from a USB Hub power supply and I use this lead, it works really well.
Most of my phone chargers now have a USB B mini on the end now so I guess would make perfect sense to go with something like that.

Regards,

Coley

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PropGFX - The home of the Hybrid Development System and PropGFX Lite

Leon

I use cheap 5V switcher wall-wart PSs.

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Leon Heller
Amateur radio callsign: G1HSM

Toby Seckshund

On "quick lash ups" I have used a voltage selectable SM. All was lovely, until I picked up the 9V lead that I usually use prior to regulators. The result was a hot Prop, a hot eeprom, a hot 74HC373 and a hot SD card.

Only the SD card survived. Now I try to always use a regulator, to isolate the Prop from my stupidity.

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Why did I think a new, more challenging, job was a good idea ??

Cluso99

Coley: That cable is a nice find from Sparkfun.

The mini-USB requires the same width but is only half the depth and much lower in height that the common CP202 barrel connector.

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
· Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz

tonyp12

As cell/mobile phones finally made it a standard to use mini-usb for charging.

I say we should make any future proto/demo board us this standard too.


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KenBash

I use these power supplies for most of my boards as well. I have the typical collection of power warts from phones gone by so shouldn't have to actually BUY one for several decades. However for those of you out there looking for the best deals, almost any second-hand store has a selection of these power supplies sitting in a plastic tub somewhere selling for one to two dollars each. With the price being so right, I usually just clip the wires, check the polarity with a meter and solder them to the correct power inputs.

Another power option that I have been surprised works so well is a small 4 AA battery pack I bought from Radio Shack. I use this with one of the demo boards inside of a little case I sometimes carry with me for demonstrating portable designs. The Prop pulls so little current that the same batteries have lasted for months for most of my applications.

I had to laugh at Beau's description of his wrapped wire, taped up power connection. I have a test system in my office with this exact same power connection. ( It ain't broke... I haven't fixed it. )

Another potential power option are the tiny sealed lead-acid batteries you can get at a battery store. Some of them are just a few inches on a side and take up little more room than one of the "Power Warts" would. I have a 6-volt that I have used for a couple of years... I hook it to a charger every few weeks when I think about it, I've never drained it so I don't really know how long it would last.

I have some friends working on nanotube batteries that are... frankly amazing in their size to storage capability, but given the current (pardon the pun) cost of nanotubes... it'll be a while down the road before they become economical, but boy... will they be great!

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" Anything worth doing... is worth overdoing. "

··············································· ( R.A.H. )
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WBA Consulting

I don't recall the last time I bought a power supply (wall wart style) other than the 7.5V from Parallax for my PPDB. I have a boxful in my garage that have been salvaged from obsoleted equipment, the latest being from my last cell phone which is a 5v, 400mA switching power supply with a mini USB connector on it. I also salvage the car adapters for cell phones, because the nice ones typically have a basic 12v to 5v switching power supply circuit. I even have an old cordless phone setup that's been partially dismantled so that I can still use the battery packs. I have one of the handsets frankensteined into a battery charger.

I also use a 9.6v NiCad battery pack meant for an RC car for most of my demoboard stuff. Picked it up at Wallymart with the charger for $5. For 12v circuits, I have two Energizer rechargeable packs that were designed as a backpack for digital picture frames. Wallymart had those on clearance for $10 (normally $40!), so I bought the 2 they had left.


Couple notes:
1) ALWAYS verify the output of a wall wart under a load. I had a 6v wall wart (unregulated, non-switching design) that had an output over 14 volts until the current draw was over 100mA, then it dropped to 6v at around 150mA. The wall wart label stated "6VDC, 400mA".

2) Use caution when using your USB ports to power your development boards. Some USB controller power management circuits don't survive surge currents or short circuits. They are supposed to per spec, but I have lost a few desktop USB ports on P4 machines by having a USB device fail and pull an excessive amount of current. It would be best to use a 250mA fuse (could be resettable type) so that if current draw is the full 500mA allowed, it will blow (Cooper Bussman AGC fuses are rated for 200% rating for 120 seconds for fast acting fuses)

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Andrew Williams
WBA Consulting
WBA-TH1M Sensirion SHT11 Module
My Prop projects: Reverse Geo-Cache Box, Custom Metronome, Micro Plunge Logger

HollyMinkowski

I have some 5v switching camera chargers that came
with a mini USB type cable. One was packed in the box of each
of those tiny keychain cameras.

Tubular

While mini USB AB is probably the "standard" way to go, a strong case can be made for USB A

1) USB A - A cables are readily available in 1/2/3/5m. If you need to connect to anything else just chop in half
2) USB A can mount in many more orientations - straight, board edge, right angle, vertical, etc
3) We can plug in usb keyboards and mice directly (with USB compatibility)
4) If Micah gets his host talking with a wide variety of devices, the cheap end of those (blueooth wifi memory sticks) are USB A

just my 2c

Ariba

I've bought some of this iPod Charging adapters: www.dealextreme.com/details.dx/sku.25863
As you see from the reviews, they do not really work as chargers for iPods, but work well to supply a Propeller
Board.
So on my new designs I only put an USB socket on the Board for PC communication, Prop programming and power supply.
No DC connector anymore. If the board is used without a PC, the USB cable goes to the adapter above. This spares:
DC connector, diode, 5V regulator.

Andy

Cluso99

miniUSB AB will accept both mini A & B cables. Cameras and phones use miniUSB-B unless they can be a master also (some cameras can output to printers). I have chosen this because I want to buy in volume and use them elsewhere on my pcbs. Since I may require a host version in the future, this makes sense to me.

Many USB keyboards still support the old PS2 mode, the USB-A connector makes most sense for these. Even the new silicon flexible keyboards support PS2 mode. Of course, the newer keyboards no doubt use less power too. I can combine the PS2 and USB-A footprints together so I can fit either.

Thanks to Micah, we now have a USB Object that can do both slave and host. The miniUSB-AB can connect to either using only adapter cables whereas you cannot buy a USB-AB. I am unsure if you can buy (readily) a cable to convert the USB-A connector (host) to a USB-B (slave). This would be a cable with the same USB connector (as on a keyboard) on both ends. Anyway, I do not want to use the full size USB A for most things because of space.

So, to recap...
* For power: Use miniUSB-AB (or miniUSB-B) as in phones and cameras (cables readily available)
* For keyboard: Use USB-A and use a USB keyboard that supports PS2 mode. (Possibly Micah could get USB mode working in 1 cog for a USB keyboard???)
* For others: Either miniUSB-AB (slave and host) or USB-A (host)

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
· Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz

Tubular

Cluso99 said...
I am unsure if you can buy (readily) a cable to convert the USB-A connector (host) to a USB-B (slave). This would be a cable with the same USB connector (as on a keyboard) on both ends. Anyway, I do not want to use the full size USB A for most things because of space.

Yes space is really the issue. Just for the record the USB A - USB A are very common, even Jaycar has 3 or 4 variants (USB2 / USB3 and different lengths). The triple USB A's used for external 2.5" drives are rarer - these have 2 USB A's at the host to grab more current, and one USB A at the drive end.

Here's a battery box I've found useful from Jaycar. Unfortunately it only contains a series power diode to drop the voltage down, rather than a LDO regulator. However the cavity has a fair bit space and you could easily install your own pcb.