Document limitations of I2C hardware

As discussed in #678, the hardware does not support zero-length read/write transactions.
rp-rs · Aug 30, 2023 · d5371de · d5371de
1 parent a12bcda
commit d5371de
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/rp2040-hal/src/i2c.rs b/rp2040-hal/src/i2c.rs
@@ -83,8 +83,16 @@ pub enum Error {
     /// I2C abort with error
     Abort(u32),
     /// User passed in a read buffer that was 0 length
+    ///
+    /// This is a limitation of the RP2040 I2C peripheral.
+    /// If the slave ACKs its address, the I2C peripheral must read
+    /// at least one byte before sending the STOP condition.
     InvalidReadBufferLength,
     /// User passed in a write buffer that was 0 length
+    ///
+    /// This is a limitation of the RP2040 I2C peripheral.
+    /// If the slave ACKs its address, the I2C peripheral must write
+    /// at least one byte before sending the STOP condition.
     InvalidWriteBufferLength,
     /// Target i2c address is out of range
     AddressOutOfRange(u16),