Can you write a list in Haskell? Then you can write embedded C code using Copilot. Here's a Copilot program that computes the Fibonacci sequence (over Word 64s) and tests for even numbers:

 fib :: Streams
 fib = do
  "fib" .= [0,1] ++ var "fib" + (drop 1 $ varW64 "fib")
  "t" .= even (var "fib")
    where even :: Spec Word64 -> Spec Bool
          even w = w `mod` const 2 == const 0

Copilot contains an interpreter, a compiler, and uses a model-checker to check the correctness of your program. The compiler generates constant time and constant space C code via Tom Hawkin's Atom (thanks Tom!). Copilot was originally developed to write embedded monitors for more complex embedded systems, but it can be used to develop a variety of functional-style embedded code.