de-LEDing a USB proto-board

smbaker

I have a project I want to make, but I don't want it blinking and illuminating the entire room like my PDB does. So, I'm wondering what it would take to eliminate the on-board LEDs? The little one by the power supply shouldn't be too hard to get to, but the ones by the USB chip look a bit tightly packed (my skill with the hot air iron does not discriminate and may inflict some collateral damage). Is there a way to programmatically turn off those USB LEDs? Looking at the USB proto-board schematic, it doesn't say what chip is used, describing it only as 'U3'.

hmm now that I think of it, some black tape over the USB LEDs might suffice. Still, it would be nice to simply turn them off.

Also, is it possible to power the board using +5 V directly to one of the 5V pads? Would it cause any grief that VR1 (LM1086-5.0) sees +5V on it's output, but it's input is unconnected?

Thanks,
Scott

davidsaunders

Just a thought:
Why not use a Propeller Proto Board without USB, and a Prop Plug?

smbaker

davidsaunders wrote: »

Just a thought:
Why not use a Propeller Proto Board without USB, and a Prop Plug?

I actually have a use for the USB interface, so the USB proto will actually work out quite nicely.

I suppose a few hints of the actual application might be handy... I have a "Chumby" alarm clock in the bedroom. I rigged up a prop to sample a photocell every so often and then output a character out the serial/USB port to tell whether it's light or dark. A corresponding script on the Chumby (it's a Linux device) reads the /dev/ttyUSB0 and dims the display accordingly. Right now it's hacked up with my professional development board. Looking to miniaturize it a little bit without bothering to have a 1-off PCB fabbed. USB Proto board seemed to fit the bill.

Pence128

IC3 is an FT232. You can use this to configure the pins the LEDs are connected to. The LED by the regulator is fixed and cannot be turned off. I suggest putting a piece of electrical tape on it.

tonyp12

http://www.ftdichip.com/Support/Utilities/FT_Prog_v1.12.zip

C0 and C1 are the LEDs

Change C0, default is TXLED#
Change C1, default is RXLED#
Change C2 ,default is TXDEN
Change C3, default is PWREN#
Change C4, default is SLEEP#

Sapieha

Hi smbaker. If You look carefully You will see traces that go from IC to led's on both sides of USB connector One by side. If You carefully cut this traces -- Led's will be disabled.

smbaker wrote: »

I actually have a use for the USB interface, so the USB proto will actually work out quite nicely.

I suppose a few hints of the actual application might be handy... I have a "Chumby" alarm clock in the bedroom. I rigged up a prop to sample a photocell every so often and then output a character out the serial/USB port to tell whether it's light or dark. A corresponding script on the Chumby (it's a Linux device) reads the /dev/ttyUSB0 and dims the display accordingly. Right now it's hacked up with my professional development board. Looking to miniaturize it a little bit without bothering to have a 1-off PCB fabbed. USB Proto board seemed to fit the bill.

kwinn

Rather than risk damaging your board by cutting or soldering just put a small blob of black silicone sealant over the led.

smbaker

Some black silicone for the power LED is the best idea yet.

Also, thanks for the replies on the FT232. Reprogramming it seems like an excellent solution to the problem. I think it's time to order a 4-pack of USB proto boards. I only wish they were smaller.