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Powering 633 with just USB - no molex

halsmgd

New member
I want to use the CFA633 in my living room, to control a PC located in my garage. I have a USB1.1 extension; one end is connected to the PC in the garage, the other to a 4-port hub in the living room.

But if I'm not mistaken, this CFA-633 will only work if a 3.5" floppy power connector is plugged into it. I've been playing around with it this week-end, and the data-sheet is not 100% clear to me, but it seems the CFA-633 needs the 5 VDC on PWR (J1?) to get power to the LCD screen and backlight. And the USB to RS-232 bridge does not seem to be supplying any power (RS-232 is a control-only interface, no pins for power supply, right?).

Does this mean the 5V line from the USB plug is not being used for anything on the CFA-633? Could I solder a line from USB's 5V line and GND to the PWR's 5V line and GND? I know USB doesn't supply many amps (0.5 is max I think), but I'm guessing its enough to power the LCD screen and backlight.

I'm surprised this question hasn't been asked before (how to power 633 with just one USB cord), but I searched the forums and couldn't find any topic related to it. Is the issue amps?

Thanks for the help, in advance!
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CF Tech

Administrator
We can configure a CFA-633-YYB (yellow) to operate from the USB with no other power (be sure to request this in your order).

The CFA-631 and CFA-635 operate from USB only with no mods, in blue or yellow or red.
 

halsmgd

New member
Thanks for the reply.

What about a CFA-633-TMC? I've already bought a pair, with the USB interface (USB633) attached. But looks like the USB633 is only connected to the RS232 interface. Can I direct the +5v and GND from USB633 to the PWR's +5v and GND?

I was reading the specs of all the jumpers, but it doesn't sound like any of the have much to do with PWR settings, except JP8 and JP9. And I don't think switching those jumpers will do my any good.
 

CF Tech

Administrator
The white & blue LEDs (TMC) have a higher forward voltage than the yellow ones. We have two in series on the CFA-633, and they will not turn on with 5v. The display itself can be jumpered to come up with the USB, but the backlight will not.

The CFA-631 and CFA-635 were designed fro USB from the start, so they work fine that way.

If you write support@crystalfontz.com and refer to this post, we will open a ticket, and maybe we can come up with a solution.
 

halsmgd

New member
That's okay. No need for a ticket. Just wondering if it was feasible.

My work-around will be to get an AC Adapater with a Molex Power Plug. I've found a "USB/IDE kit" that goes for $10.99 and includes a simple molex/AC adapter, which should do the trick. The $11 won't break me, I just didn't want to have to run another cord to the unit if I didn't have to.

So if I understand this correctly, it uses 12 VDC to power the backlight?

BTW, thanks for your replies. You guys have an awesome little gadget.

Also, if anyone is interested on how to make this work C# in VS2005, I've some code I could post. The new System.IO.Ports.SerialPort class makes it a snap. The only real trick was reading the doco to find the correct baud rate (I thought the default 9600 would do, but it turned out the CFA-633-TMC is 19200). Be sure to set that in Device Manager, or the commands you issue won't be recognized by the unit.
 

TrickyD

New member
That's okay. No need for a ticket. Just wondering if it was feasible.

My work-around will be to get an AC Adapater with a Molex Power Plug. I've found a "USB/IDE kit" that goes for $10.99 and includes a simple molex/AC adapter, which should do the trick. The $11 won't break me, I just didn't want to have to run another cord to the unit if I didn't have to.

So if I understand this correctly, it uses 12 VDC to power the backlight?

BTW, thanks for your replies. You guys have an awesome little gadget.

Also, if anyone is interested on how to make this work C# in VS2005, I've some code I could post. The new System.IO.Ports.SerialPort class makes it a snap. The only real trick was reading the doco to find the correct baud rate (I thought the default 9600 would do, but it turned out the CFA-633-TMC is 19200). Be sure to set that in Device Manager, or the commands you issue won't be recognized by the unit.

I would love to see your C# code example, I'm playing with one of these and could really use a sample on the C# platform.

Thanks in advance.
 

inno

New member
We can configure a CFA-633-YYB (yellow) to operate from the USB with no other power (be sure to request this in your order).

The CFA-631 and CFA-635 operate from USB only with no mods, in blue or yellow or red.
Is there a standard part number to request this modification? Is it available for the RS-232 (-KS) version as well?

Thanks!
 

CF Support2

Administrator
Since we have had a few requests for this modification recently, we wanted to pass on that it is no longer supported.

The introduction of the CFA533 series has eliminated the need to make this modification to the CFA633-YYB-KU. The CFA533 operates with a 3.3v to 5v supply and is powered through the USB header on the USB interface variants. Since there is no +12v supply, there is also no fan support. When the CFA633-YYB-KU was modded for +5v only operation, fan support was also lost.

https://www.crystalfontz.com/product/cfa533yyhku-16x2-display-character-module-usb

https://www.crystalfontz.com/product/cfa533tmiku-display-module-usb-16x2-character

This way, we can fully support a +5v only part.

If you require fan control support, then you'll need to use a CFA633 series.
 

topteks

New member
That's okay. No need for a ticket. Just wondering if it was feasible.

My work-around will be to get an AC Adapater with a Molex Power Plug. I've found a "USB/IDE kit" that goes for $10.99 and includes a simple molex/AC adapter, which should do the trick. The $11 won't break me, I just didn't want to have to run another cord to the unit if I didn't have to.

So if I understand this correctly, it uses 12 VDC to power the backlight?

BTW, thanks for your replies. You guys have an awesome little gadget.

Also, if anyone is interested on how to make this work C# in VS2005, I've some code I could post. The new System.IO.Ports.SerialPort class makes it a snap. The only real trick was reading the doco to find the correct baud rate (I thought the default 9600 would do, but it turned out the CFA-633-TMC is 19200). Be sure to set that in Device Manager, or the commands you issue won't be recognized by the unit.
halsmgd, would if be possible to take a look at the code you mentioned you have in C# / VS2005?
 
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