I recently picked up a Sparkfun LoRa Serial Kit.
Admittedly I’m pretty green when it comes to Serial so I’m struggling through this a bit with limited success.
My main question is what serial is this device okay to support?
LoRaSerial is designed to get small amounts of data from point A to point B as easily as possible. If you’ve got a sensor, or Arduino, or any device that can output serial, then it can transmit data over long distances. LoRaSerial has been used to send data over 9 miles (14 km) line-of-sight.
My lizard brain was like “hmmm I have a sensor, yes it’s serial. Great! this is all i need”
Details you probably don’t need but I’ll vomit into the universe:
I’m in the bit of an I/O pinch and need to get a serial pressure sensor, either an in-situ rugged troll 200 or GeoKon 8960 interface, to talk to a Campbell Scientific Data Logger Com port (only Tx and Rx). Unsurprisingly both of these sensors are RS-485.
The Campbell Scientific Logger has 0-5V RS-232 on the com port: e.g. Com2 has Ground TX and RX. I can also switch to TTL which I think just inverts the logic.
COMMUNICATION 9.1 – 8 10 30 RS-232 PORTS: DCE nine-pin: (not electrically isolated) for computer connection or connection of modems not manufactured by Campbell Scientific. COM1 to COM2: two independent Tx/Rx pairs on control ports (non-isolated); 0 to 5 Vdc UART Baud Rate: selectable from 300 bps to 115.2 kbps. Default Format: eight data bits; one stop bits; no parity. Optional Formats: seven data bits; two stop bits; odd, even parity.
From what I can tell this should work.
Unfortunately when I plug this into a rs-232→rs-485 converter the return logic level is 0-10V. I didn’t realize the return logic was out of spec (both for the CS logger and the Lora Serial Kit). I did test it this way (sans LoRa) which did work. but not something I plan on repeating.
I’m not sure if the LoRa Serial kit can handle 0-5V RS232 or if it’s worth my time trying to find level shifter or isolated converter or something that will keep both sides of the LoRa happy.
This kit would be fire if it could support RS-485 
@TS-Russell
I work with hundreds of RS-485 instruments that need like 6 registers polled every 4 hours LoRa with RS-485 that isn’t proprietary would definitely be a hard item to keep in stock.
My next step may be to try a TTL to RS 485 converter rather than RS-232. But I do have to say running down the rabbit hole of what is RS-232 has not been an enlightening experience
