From 554a75595e6865aee30289e09b64e88b7f24fdaa Mon Sep 17 00:00:00 2001 From: Jorge Aparicio Date: Tue, 14 Jul 2020 10:01:33 +0000 Subject: [PATCH] Update embedded-workshop-book/src/beginner-next-steps.md Co-authored-by: Lotte Steenbrink --- embedded-workshop-book/src/beginner-next-steps.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/embedded-workshop-book/src/beginner-next-steps.md b/embedded-workshop-book/src/beginner-next-steps.md index 5c8363a..13db190 100644 --- a/embedded-workshop-book/src/beginner-next-steps.md +++ b/embedded-workshop-book/src/beginner-next-steps.md @@ -6,7 +6,7 @@ If you've already completed the main workshop tasks or would like to explore mor If you check the API documentation of the `Radio` abstraction we have been using you'll notice that we haven't used these methods: `energy_detection_scan()`, `set_cca()` and `try_send()`. -The first method scans the currently selected channel (see `set_channel`), measures the energy level of ongoing radio communication in this channel and returns the maximum energy observed over a span of time. This method can be used to determine what the *idle* energy level of a channel is. If there's non-802.15.4 traffic ongoing on this channel the method will return a high value. +The first method scans the currently selected channel (see `set_channe()l`), measures the energy level of ongoing radio communication in this channel and returns the maximum energy observed over a span of time. This method can be used to determine what the *idle* energy level of a channel is. If there's non-IEEE 802.15.4 traffic on this channel the method will return a high value. Under the 802.15.4 specification, before sending a data packet devices must first check if there's communication going on in the channel. This process is known as Clear Channel Assessment (CCA). The `send` method we have been used performs CCA in a loop and sends the packet only when the channel appears to be idle. The `try_send` method performs CCA *once* and returns the `Err` variant is the channel appears to be busy. In this failure scenario the device does not send any packet.