diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,8 +1,14 @@
+zephyr-copilot (1.0.2) upstream; urgency=medium
+
+  * Update to copilot-3.9.
+
+ -- Joey Hess <id@joeyh.name>  Sun, 08 May 2022 15:14:11 -0400
+
 zephyr-copilot (1.0.1) upstream; urgency=medium
 
   * Small documentation fixes.
 
- -- Joey Hess <id@joeyh.name>  Tue, 15 Feb 2022 11:13:41 -0400
+ -- Joey Hess <id@joeyh.name>  Sun, 08 May 2022 15:12:10 -0400
 
 zephyr-copilot (1.0.0) unstable; urgency=medium
 
diff --git a/Examples/Blink/stack.yaml b/Examples/Blink/stack.yaml
--- a/Examples/Blink/stack.yaml
+++ b/Examples/Blink/stack.yaml
@@ -3,13 +3,13 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- sketch-frp-copilot-1.0.1
-- copilot-3.7
-- copilot-c99-3.7
-- copilot-core-3.7
-- copilot-language-3.7
-- copilot-libraries-3.7
-- copilot-theorem-3.7
+- sketch-frp-copilot-1.0.2
+- copilot-3.9
+- copilot-c99-3.9
+- copilot-core-3.9
+- copilot-language-3.9
+- copilot-libraries-3.9
+- copilot-theorem-3.9
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/Button/stack.yaml b/Examples/Button/stack.yaml
--- a/Examples/Button/stack.yaml
+++ b/Examples/Button/stack.yaml
@@ -3,13 +3,13 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- sketch-frp-copilot-1.0.1
-- copilot-3.7
-- copilot-c99-3.7
-- copilot-core-3.7
-- copilot-language-3.7
-- copilot-libraries-3.7
-- copilot-theorem-3.7
+- sketch-frp-copilot-1.0.2
+- copilot-3.9
+- copilot-c99-3.9
+- copilot-core-3.9
+- copilot-language-3.9
+- copilot-libraries-3.9
+- copilot-theorem-3.9
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/Feather/stack.yaml b/Examples/Feather/stack.yaml
--- a/Examples/Feather/stack.yaml
+++ b/Examples/Feather/stack.yaml
@@ -3,13 +3,13 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- sketch-frp-copilot-1.0.1
-- copilot-3.7
-- copilot-c99-3.7
-- copilot-core-3.7
-- copilot-language-3.7
-- copilot-libraries-3.7
-- copilot-theorem-3.7
+- sketch-frp-copilot-1.0.2
+- copilot-3.9
+- copilot-c99-3.9
+- copilot-core-3.9
+- copilot-language-3.9
+- copilot-libraries-3.9
+- copilot-theorem-3.9
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/TODO b/TODO
--- a/TODO
+++ b/TODO
@@ -1,8 +1,7 @@
-for first release:
+for second release:
 	USB serial interface
-
-	PWM (or remove unported code) 
-	ADC (or remove unported code)
+	PWM
+	ADC
 
 later:
 	Write more board modules for Zerphyr's many boards.
@@ -11,8 +10,8 @@
 	etc). Unfortunately does not include GPIO pins beyond the user led
 	and switch for most boards.
 	
-	Also see arduino-copilot's TODO list for some generic ideas that
-	are also applicable here.
-	
 	Zephyr has many libraries and capabilities, that could all be
 	supported.
+	
+	Also see arduino-copilot's TODO list for some generic ideas that
+	are also applicable here. And sketch-frp-copilot's TODO.
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,13 +2,13 @@
 - '.'
 resolver: lts-18.9
 extra-deps:
-- sketch-frp-copilot-1.0.1
-- copilot-3.7
-- copilot-c99-3.7
-- copilot-core-3.7
-- copilot-language-3.7
-- copilot-libraries-3.7
-- copilot-theorem-3.7
+- sketch-frp-copilot-1.0.2
+- copilot-3.9
+- copilot-c99-3.9
+- copilot-core-3.9
+- copilot-language-3.9
+- copilot-libraries-3.9
+- copilot-theorem-3.9
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/zephyr-copilot.cabal b/zephyr-copilot.cabal
--- a/zephyr-copilot.cabal
+++ b/zephyr-copilot.cabal
@@ -1,5 +1,5 @@
 Name: zephyr-copilot
-Version: 1.0.1
+Version: 1.0.2
 Cabal-Version: >= 1.10
 License: BSD3
 Maintainer: Joey Hess <id@joeyh.name>
@@ -72,10 +72,10 @@
     Copilot.Zephyr.Main
   Build-Depends:
     base (>= 4.5 && < 5),
-    sketch-frp-copilot (== 1.0.1),
-    copilot (== 3.7.*),
-    copilot-c99 (== 3.7.*),
-    copilot-language (== 3.7.*),
+    sketch-frp-copilot (== 1.0.2),
+    copilot (== 3.9.*),
+    copilot-c99 (== 3.9.*),
+    copilot-language (== 3.9.*),
     filepath,
     directory,
     mtl,