injecting data into hardware serial

Using Arduino Programming Questions
#1

Hello,

I'm facing quite a challenge.

I have a couple of Mega 2560s with RFM22 SparkFun RFM22 Shield - 434MHz - DEV-11018 - SparkFun Electronics 433Mhz radio shields on top of each.
I've established a serial bridge between the two - easy.

Now, it gets complicated then I'm trying to use serial event libraries, like CmdMessenger (GitHub - dreamcat4/CmdMessenger2: Fork of Neil Dudman's CmdMessenger. Serial messaging system for Arduino platform) or it's light weight version - SerialCommand (A Minimal Arduino Library for Processing Serial Commands – The inability to follow simple instructions)

Since RFM22 operates on SPI bus, serial events aren't processed, meaning radio packets bypass Hardware Serial library.

I wonder how difficult would it be to programatically inject every byte received from RFM22 chip (rf22.recvfrom()) into Hardware Serial's rx_buffer?
It looks like HardwareSerial.ccp doesn't have any public variables/methods to enable manipulation of the rx_buffer (Google Code Archive - Long-term storage for Google Code Project Hosting.)

I've currently physically interconnected Mega's Serial1->Serial0, and am writing RFM22 packets into Serial1, what fills Serial0 buffer and makes Serial event libraries to work, but that's a poor-man's approach

Any advices are welcome

#2

I think you're screwed unless you modify HardwareSerial.cpp because all the variables you need are private.

Either that or write your own version and work directly with the UART.

Rob

#3

I think it would be a lot simpler to clone the library that uses serial events and reads from the hardware serial buffer, to use different type(s) of events (that you generate) and reads from a buffer that you manage (containing radio data).

#4

Did you ever find the solution to this problem? I’m trying to do pretty much the same thing and running into the same problem.

From what I’ve read I suspect it could be done by setting up a Stream to bridge between the radio library (which outputs a String) and the CmdMessenger library but I haven’t worked out how to do that yet.

#5