diff --git a/micropython/aiorepl/aiorepl.py b/micropython/aiorepl/aiorepl.py
index 8ebaef079..8b3ce4f8c 100644
--- a/micropython/aiorepl/aiorepl.py
+++ b/micropython/aiorepl/aiorepl.py
@@ -1,6 +1,7 @@
 # MIT license; Copyright (c) 2022 Jim Mussared
 
 import micropython
+from micropython import const
 import re
 import sys
 import time
diff --git a/micropython/drivers/codec/wm8960/wm8960.py b/micropython/drivers/codec/wm8960/wm8960.py
index 573fce5e9..dc0dd655d 100644
--- a/micropython/drivers/codec/wm8960/wm8960.py
+++ b/micropython/drivers/codec/wm8960/wm8960.py
@@ -683,7 +683,7 @@ def alc_mode(self, channel, mode=ALC_MODE):
         )
         self.regs[_ALC3] = (_ALC_MODE_MASK, mode << _ALC_MODE_SHIFT)
         try:
-            rate = _alc_sample_rate_table[self.sample_rate]
+            rate = self._alc_sample_rate_table[self.sample_rate]
         except:
             rate = 0
         self.regs[_ADDCTL3] = (_DACCTL3_ALCSR_MASK, rate)
diff --git a/micropython/drivers/imu/bmm150/bmm150.py b/micropython/drivers/imu/bmm150/bmm150.py
index b7b4aad30..036b2b258 100644
--- a/micropython/drivers/imu/bmm150/bmm150.py
+++ b/micropython/drivers/imu/bmm150/bmm150.py
@@ -165,9 +165,6 @@ def _compensate_z(self, raw, hall):
             z = (z5 / (z4 * 4)) / 16
         return z
 
-    def reset(self):
-        self._write_reg(_CMD, 0xB6)
-
     def magnet_raw(self):
         for i in range(0, 10):
             self._read_reg_into(_DATA, self.scratch)
diff --git a/micropython/drivers/imu/lsm6dsox/lsm6dsox.py b/micropython/drivers/imu/lsm6dsox/lsm6dsox.py
index 1e4267ae7..1952c5bb1 100644
--- a/micropython/drivers/imu/lsm6dsox/lsm6dsox.py
+++ b/micropython/drivers/imu/lsm6dsox/lsm6dsox.py
@@ -46,6 +46,7 @@
 
 import array
 from micropython import const
+import time
 
 _CTRL3_C = const(0x12)
 _CTRL1_XL = const(0x10)
diff --git a/micropython/drivers/imu/lsm9ds1/lsm9ds1.py b/micropython/drivers/imu/lsm9ds1/lsm9ds1.py
index 7123a574b..e3d46429d 100644
--- a/micropython/drivers/imu/lsm9ds1/lsm9ds1.py
+++ b/micropython/drivers/imu/lsm9ds1/lsm9ds1.py
@@ -44,6 +44,7 @@
     time.sleep_ms(100)
 """
 import array
+from micropython import const
 
 
 _WHO_AM_I = const(0xF)
diff --git a/micropython/drivers/sensor/lps22h/lps22h.py b/micropython/drivers/sensor/lps22h/lps22h.py
index ca29efce2..1e7f4ec3e 100644
--- a/micropython/drivers/sensor/lps22h/lps22h.py
+++ b/micropython/drivers/sensor/lps22h/lps22h.py
@@ -38,6 +38,7 @@
     time.sleep_ms(10)
 """
 import machine
+from micropython import const
 
 _LPS22_CTRL_REG1 = const(0x10)
 _LPS22_CTRL_REG2 = const(0x11)
diff --git a/micropython/mip/mip/__init__.py b/micropython/mip/mip/__init__.py
index 5f6f4fcd6..68daf32fe 100644
--- a/micropython/mip/mip/__init__.py
+++ b/micropython/mip/mip/__init__.py
@@ -1,6 +1,7 @@
 # MicroPython package installer
 # MIT license; Copyright (c) 2022 Jim Mussared
 
+from micropython import const
 import requests
 import sys
 
diff --git a/micropython/net/webrepl/webrepl.py b/micropython/net/webrepl/webrepl.py
index 56767d8b7..48c181968 100644
--- a/micropython/net/webrepl/webrepl.py
+++ b/micropython/net/webrepl/webrepl.py
@@ -1,6 +1,7 @@
 # This module should be imported from REPL, not run from command line.
 import binascii
 import hashlib
+from micropython import const
 import network
 import os
 import socket
diff --git a/micropython/uaiohttpclient/example.py b/micropython/uaiohttpclient/example.py
index 4134c7ee7..5c03ee29f 100644
--- a/micropython/uaiohttpclient/example.py
+++ b/micropython/uaiohttpclient/example.py
@@ -9,7 +9,7 @@ def print_stream(resp):
     print((yield from resp.read()))
     return
     while True:
-        line = yield from reader.readline()
+        line = yield from resp.readline()
         if not line:
             break
         print(line.rstrip())
diff --git a/pyproject.toml b/pyproject.toml
index 6828563c9..1aa9c1122 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,7 +62,6 @@ ignore = [
   "F403",
   "F405",
   "F541",
-  "F821",
   "F841",
   "ISC003",  # micropython does not support implicit concatenation of f-strings
   "PIE810",  # micropython does not support passing tuples to .startswith or .endswith
@@ -91,3 +90,10 @@ max-statements = 166
 
 [tool.ruff.per-file-ignores]
 "micropython/aiorepl/aiorepl.py" = ["PGH001"]
+
+# manifest.py files are evaluated with some global names pre-defined
+"**/manifest.py" = ["F821"]
+"ports/**/boards/manifest*.py" = ["F821"]
+
+# ble multitests are evaluated with some names pre-defined
+"micropython/bluetooth/aioble/multitests/*" = ["F821"]
diff --git a/python-ecosys/cbor2/cbor2/decoder.py b/python-ecosys/cbor2/cbor2/decoder.py
index f0784d4be..48ff02d89 100644
--- a/python-ecosys/cbor2/cbor2/decoder.py
+++ b/python-ecosys/cbor2/cbor2/decoder.py
@@ -160,7 +160,7 @@ def decode_simple_value(decoder):
 
 def decode_float16(decoder):
     payload = decoder.read(2)
-    return unpack_float16(payload)
+    raise NotImplementedError  # no float16 unpack function
 
 
 def decode_float32(decoder):
@@ -185,7 +185,7 @@ def decode_float64(decoder):
     20: lambda self: False,
     21: lambda self: True,
     22: lambda self: None,
-    23: lambda self: undefined,
+    # 23 is undefined
     24: decode_simple_value,
     25: decode_float16,
     26: decode_float32,
diff --git a/python-ecosys/iperf3/iperf3.py b/python-ecosys/iperf3/iperf3.py
index 62ee01683..a5c54445d 100644
--- a/python-ecosys/iperf3/iperf3.py
+++ b/python-ecosys/iperf3/iperf3.py
@@ -380,9 +380,11 @@ def client(host, udp=False, reverse=False, bandwidth=10 * 1024 * 1024):
     ticks_us_end = param["time"] * 1000000
     poll = select.poll()
     poll.register(s_ctrl, select.POLLIN)
+    buf = None
     s_data = None
     start = None
     udp_packet_id = 0
+    udp_last_send = None
     while True:
         for pollable in poll.poll(stats.max_dt_ms()):
             if pollable_is_sock(pollable, s_data):