Permanently installing a USB dongle

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AMDlloydsp
Posts: 99
Joined: Mon Apr 15, 2013 3:51 pm
Location: NE Central FL

Permanently installing a USB dongle

Post by AMDlloydsp » Tue Jan 28, 2014 1:51 am

I have some projects built around SuperPro boards which cannot be easily opened for service (sealed enclosures in an explosive atmosphere). Therefore, to do routine software maintenance I have to install a USB dongle and cable onto each SuperPro, and route the end of the USB cable to an easier-to-open 'service port'.

Normally, just having the dongle plugged in will cause the SuperPro to enter the programming mode, even if the cable is not connected to the PC. But, there's a way to prevent this. It takes one mod and one jumper on the USB dongle, and one jumper on the SuperPro to do.

Basically, this is the procedure, and a .pdf with photos is attached:
On the Dongle,
1) On top of the board, cut the +5V run between pin 1 of the USB Mini-B connector and pin 1 of the 4-pin header pad just down-board from the connector.
Space is tight here. Use a sharp, narrowly tapered knife like a pointed Xacto knife to cut the run in two spots, and pop off cutout piece with the tip of a hot soldering iron and light pressure on the tip.
2) solder a jumper across the steering diode which is near the USB connector, on the left as the board is viewed from the USB connector end.

On the SuperPro
3 solder a jumper or a header and shorting plug across J16, which bypasses the power steering diode on the SuperPro.

In this configuration, be careful not to connect the USB cable to un-powered equipment, because the equipment might try to power itself from the SuperPro's 5V supply!

'Hope this helps someone!

Lloyd (photos attached)
Attachments
photos and schematic.pdf
photos and schematic for USB el permanente' on SuperPro
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