I am bringing in RS-232 data from a weather station and want to format and output on WiFi link. I have Ardunio Uno and WiFi Shield, how do I bring in RS-232 Data?
Dennis
how do I bring in RS-232 Data
You may have to invert the rs-232 signal into a TTL signal. A transistor and two resistors could do the job.
OK first up, RS-232 is a 15 volt line driven signal - not something you want to stuff into an arduino. There are a number of devices available that quickly and simply read 232 and convert it to TTL which is at least not going to fry things.
My guess would be something based on a MAX232 chip. (or it's smarter brother the MAX3232)
Not sure if this is what I think it is, but here's an RS232 shield based on the MAX3232: http://www.ecrater.com/p/12583357/mini-max3232-rs232-shield-board?gps=1
Hope this gives you some ideas
My question is that the RX and TX lines go to the WIFI shield, where would I bring in the RS-232 data (Serial TTL) logic level?
Thanks Dennis
DennisR:
My question is that the RX and TX lines go to the WIFI shield, where would I bring in the RS-232 data (Serial TTL) logic level?
If you connect your RS232 to a shield, then obviously there is the possibility that you will get conflicts in the pin assignments of your other shields. You could look for an alternative shield that uses a different pin assignment. You could use an 'in between' shield to re-route the pins between layers. You could use a separate board (instead of a shield) which then enables you to connect it to arbitrary pins. If the logic level serial signal can't be routed to the hardware serial UART (pins 0 and 1) (and you don't have an Arduino with any other hardware UARTS free) then you have the option of using SoftwareSerial on any free pair of I/O pins. I understand that SoftwareSerial is not capable of keeping up with very high line speeds but I don't know what the limit is - just be aware that if you take this approach it may rule out higher line speeds.