ASA DDM60 (PRO) USB Fix

We had a nearby lightning strike in June 2024 and although there is an UPS there was an impact on the DDM 60 mount. No connection was possible anymore from Autoslew to the mount, just throwing an error and switching to sim mode.

After inspection it was obvious that the onboard FTDI chip was fried by the overcurrent.

Since an replacement PCB is 1.000+ EUR, I searched for an alternative.

The heart of the PCB is a TMS 320F2808PZA Digital Signal Processor from Texas Instrument, which is directly connected with it’s serial lines to a FTDI FT232RQ serial-to-USB converter. The later is going to the „COM“ labeled port and will handle all communiction with Autoslew.

My solution was to look for the RX/TX wires of the TMS980, and useage of an external USB Dongle.

Details of the FTDI Chip

Details of the TMS Chip

It is necessary to use a TTL converter for the TX and RX lines and to find a 3.3 or 5V source. Luckily there are some unused ports which exactly delivers these voltages.

You can find detailled images of the complete process here:

https://photos.app.goo.gl/crkguBYPYr7sXahM7

Please note that you need an USB Dongle with FTDI chip, others won’t work.

For me these devices were working:

If you have more than one device with an FTDI converter, it’s necessary to reprogram the Description of the USB dongle connected to the DDM.