I'm trying to interface an XSens IMU with my computer, and I'm running into interesting difficulties. The IMU has an RS232 connector that just uses the pins VCC, GND, TX, RX, nothing else. The SDK comes with it has a custom RS232-USB adapter that uses the FT232R and MAX3160, but apart from that it doesn't seem to do anything special.
The manufacturer claims that the IMU uses standard RS232 (and I have no reason to doubt them), so, in order to save space (their converter is quite bulky), I am trying to use a Sparkfun FTDI Basic Breakout 5V.
If I set all the COM settings the same (baudrate, parity, stop, etc), and I connect to the device, I do get data back, but it just seems like gibberish. I issue commands, the TX LED on the FTDI blink, the RX one too, and I get data, but it's nothing like what I am expecting.
Can anyone think of any "gotchas" I may be missing?
Is there a FooBar that needs to be connected to the DingDing to Actuate?
Best Answer
Standard rs-232 (like your IMU) and TTL level rs-232 (like the FTDI chip) are different.
Standard rs-232 switches between +V and -V ( where V was originally 12, but now most devices will work on much lower voltages). TTL level rs-232 switches between 0 and 5V. You need an rs-232 transceiver to convert the voltages, such as that MAX3160 chip (Though that's an unusual one - something like the max2332 is more common).
The USB to TTL level rs-232 converters like the one you linked to are are used to connect to a microcontroller, not to a typical rs-232 device.