- Sat Jul 18, 2009 4:16 pm
#77282
Just wanted to give super thanks to Sparkfun for their FT232R Breakout board! It allowed me to test an idea for an isolated RS-232 to USB converter. Basically the FT232RL part is coupled to the new Analog Devices ADM3251 Isolated RS-232 to TTL serial chip.
I have an engine controller module (microsquirtmodule.com) and an isolated serial link arrangement is extremely desirable. As everyone knows, an automotive environment is very hostile and when you connect a PC it can be brutal.
Anyway, the arrangement with the two devices provides total isolation, and provides a RS232-to-USB conversion that is needed.
I tested this using the FT232R Breakout board and a ADI EVAL-ADM3251 eval board. The FTDI chip is powered by the PC USB link, as is half of the ADM chip. The ADM chip has an internal DC-DC converter to provide +/-12V on the other side, and the Tx and RX are isolated using the Icoupler technology - basically tiny transformers inside of the chip (and they can pass DC signals, too). Result is total isolation! Sometimes being isolated is a good thing....
The overall schematic is located here: http://www.microsquirtmodule.com/circuit_addons.html
Thanks again for making the breakout board - it really helped with mocking up the circuit
And, if you ever wanted to make an isolated RS-232 to USB board, please do! I will point a bunch of people over to it! Keep up the fantastic work, its awesome
- Bruce
Do-it-yourself EFI - www.megamanual.com
I have an engine controller module (microsquirtmodule.com) and an isolated serial link arrangement is extremely desirable. As everyone knows, an automotive environment is very hostile and when you connect a PC it can be brutal.
Anyway, the arrangement with the two devices provides total isolation, and provides a RS232-to-USB conversion that is needed.
I tested this using the FT232R Breakout board and a ADI EVAL-ADM3251 eval board. The FTDI chip is powered by the PC USB link, as is half of the ADM chip. The ADM chip has an internal DC-DC converter to provide +/-12V on the other side, and the Tx and RX are isolated using the Icoupler technology - basically tiny transformers inside of the chip (and they can pass DC signals, too). Result is total isolation! Sometimes being isolated is a good thing....
The overall schematic is located here: http://www.microsquirtmodule.com/circuit_addons.html
Thanks again for making the breakout board - it really helped with mocking up the circuit
And, if you ever wanted to make an isolated RS-232 to USB board, please do! I will point a bunch of people over to it! Keep up the fantastic work, its awesome - Bruce
Do-it-yourself EFI - www.megamanual.com