Merge pull request #8 from jetannenbaum/master

[micorpython_ir.git] / README.md

diff --git a/README.md b/README.md
index e2c10d8152d05f871c54492e3fed5a2ac380da20..48259c5f25034e06ae3c675d27b87bae22be717c 100644 (file)
--- a/README.md
+++ b/README.md
@@ -13,15 +13,14 @@ and data values associated with buttons on a remote control. The transmitter is
 then used in an application to send those codes, emulating the remote control.
 
 Other use cases involve running the receiver in an application. This enables an
-IR remote to control a device such as a robot.
+IR remote to control a device such as a robot. This may be problematic on some
+platforms. Please see [section 4](./README.md#4-receiver-limitations).
 
 ## Raspberry Pi Pico note
 
 Early firmware has [this issue](https://github.com/micropython/micropython/issues/6866)
-affecting USB communication with some PC's. It particularly affects code which
-issues `print()` only occasionally: the application appears to have failed. The
-missing messages appear when you press a key. Hopefully this will be fixed soon
-(note dated 8th March 2021).
+affecting USB communication with some PC's. This is now fixed. Please ensure
+you are using up to date firmware.
 
 #### [Receiver docs](./RECEIVER.md)
 
@@ -96,7 +95,15 @@ proprietary protocols and are not supported by these drivers.
 | Samsung   | 38    | Measured      | N       |
 | Panasonic | 36.3  | Measured      | N       |
 
-# 4. References
+# 4. Receiver limitations
+
+The receiver uses a pin interrupt and depends on a quick response to a state
+change on the pin. This is guaranteed on platforms which support hard IRQ's
+such as the Pyboard and the RP4 Pico. The ESP32 and ESP8266 only support soft
+IRQ's. This means that, if code such as WiFi communication is running
+concurrently, reliable reception may be problematic.
+
+# 5. References
 
 Sources of information about IR protocols. The `sbprojects.net` site is an
 excellent resource.