Software » Canbridge

h1. Modes

h2. Stubborn

* Send CAN messages as Broadcast messages; fire and forget

* Good enough for sensor values

* Robust code, not much that can fail

* Not good enough for e.g. Flashing firmware on remote device or even scanning nodes.

h2. Guaranteed

* Each package need an acknowledge

* Retransmitts are send if acknowledge is missing

* Heavy traffic if nodes are blocking each other.

* Complex code, but ok

h1. Retransmits

* In starting phase there is an auto-tune which requires traffic

* There are at least some CRC errors

h1. Send package

* ringTransmitted.canPush()?

* store essage there

* Send it via RFM69

h2. Receive package

* If type is "Acknowledge"

** find corresponding message

** mark slot as acked/nacked

* If regular message/resend

** If resend: is the package older than the last?, drop it

** is it not last+1? send NACK via RFM69

** fill it in the receive buffer

** directly send acknowledge via RFM69

h2. Loop

* iterate Slots

* If WAITing: is message is older than ??ms, perform an resend

* If ACKed, pop it from the ring. Not the first non-ACKed? Error

* If NACKed, resend it, if there is no WAITing before 

h2. Open points

* Acknowledge gets lost; retransmit started

** last-id for every net. Drop message if it matches

* RFM-Class receives messages in ISR as fast as possible. Sending acknowledge is done in the loop. 

** Order should be preserved.

** Makes things super slow