Prop to Prop communication

Damo

Can I use the fullduplexserialplus to have two props communicate and pass data back and forth. I've tried, but don't get good results.
I've also tried the fast inter-propellor-communication file from the OBEX, but can;t get my props talking that way either.
Any suggestions ?

Cluso99

I use FullDuplexSerial_rr004 which is my version set with default buffers of 256 bytes. I run at 115,200 baud without problems. The cips need to be in close proximity. There is a faster object by Beau, but at least get this running first.

Duane Degn

I usually use 10K pull-up resistors on the com lines with my Prop to Prop projects.

I've found Tracy Allen's version of a four port serial driver works well for Prop to Prop communication since it includes a check for framing errors.

I've modified Tracy's version to check for an end of message character. When this character (I usually use a carriage return) is detected by the PASM driver, it increments a variable. When the main program sees this variable has increased, it then processes the message. This way I don't have to keep moving bytes around of partial messages.

I don't think I've posted my most recent modification. I'll post it if you're interested.

The downside to using an end of message character is you need to limit your communication to ASCII characters so your data doesn't include the end of message character. This is one of many issues that come up when deciding about a Prop to Prop communication protocol.