README.txt
==========

psmq is publish subscribe message queue. It's a set of programs and libraries
to implement publish/subscribe way of inter process communication on top of
POSIX message queue.

Manuals, source code and more info at:
https://psmq.kurwinet.pl


Little demo using psmqd broker, psmq_pub and psmq_sub:

# start broker and make it log to file
  nsh> psmqd -b/brok -p/sd/psmqd/psmqd.log

# start subscribe thread that will read all messages send on /can/* topic
  nsh> psmq_sub -n/sub -b/brok -t/can/* -o/sd/psmq-sub/can.log
  n/connected to broker /brok
  n/subscribed to /can/*
  n/start receiving data

# publish some messages
  nsh> psmq_pub -b/brok -t/can/engine/rpm -m50
  nsh> psmq_pub -b/brok -t/adc/volt -m30
  nsh> psmq_pub -b/brok -t/can/room/10/temp -m23
  nsh> psmq_pub -b/brok -t/pwm/fan1/speed -m300

# check out subscribe thread logs
  nsh> cat /sd/psmq-sub/can.log
  [1970-01-01 00:00:53] topic: /can/engine/rpm, priority: 0, paylen: 3, payload:
  [1970-01-01 00:00:53] 0x0000  35 30 00                                         50.
  [1970-01-01 00:00:58] topic: /can/room/10/temp, priority: 0, paylen: 3, payload:
  [1970-01-01 00:00:58] 0x0000  32 33 00                                         23.

As you can see /adc/volt and /pwm/fan1/speed haven't been received by subscribe
thread.

Content:

* psmqd - broker, relays messages between clients
* psmq_sub - listens to specified topics, can be used as logger for
  communication (optional)
* psmq_pub - publishes messages directly from shell. Can send binary data, but
  requires pipes, so on nuttx it can only send ASCII.
* libpsmq - library used to communicate with the broker and send/receive
  messages