Implement async uart receive

Cargo.toml

@@ -11,25 +11,29 @@ bench = false
 [dependencies]
 panic-halt = "1.0.0"
 ch32-hal = {git = "https://github.com/ch32-rs/ch32-hal", features = [
-	"ch32v003f4p6",
-	"embassy",
+    "ch32v003f4p6",
+    "embassy",
+    "time-driver-tim2",
 ]}
-qingke-rt = { version = "0.4.0", features = ["highcode"] }
-qingke = "0.4.0"
+qingke-rt = { version = "0.5.0", features = ["highcode"] }
+qingke = "0.5.0"
 embedded-hal = "1.0.0"
 
 embassy-executor = {version = "0.6.0", features = [
-#    "integrated-timers",
+    "integrated-timers",
     "arch-spin",
     "executor-thread",
-    "task-arena-size-128", # or better use nightly, but fails on recent Rust versions
+    "task-arena-size-320", # see https://docs.embassy.dev/embassy-executor/git/cortex-m/index.html#task-arena-size
 ]}
-embassy-time = { version = "0.3.0" }
 fugit = "0.3.7"
 
+[profile.release]
+strip = true
+opt-level = "z"
+lto = "fat"
+
 [profile.dev]
 strip = false   # symbols are not flashed to the microcontroller, so don't strip them.
-lto = true
 opt-level = "s" # Optimize for size.
 
 [dev-dependencies]