Plutus Playground Smart Contract (should adapt from https://gist.github.com/j-mueller/db9bb00b6b45fe7e475e75473c1e778b)

Playground.hs

-- This is a starter contract, based on the Game contract,
-- containing the bare minimum required scaffolding.
--
-- What you should change to something more suitable for
-- your use case:
--   * The DataScript type
--   * The Redeemer type
--
-- And add function implementations (and rename them to
-- something suitable) for the endpoints:
--   * publish
--   * redeem

import qualified Language.PlutusTx          as PlutusTx
import           Language.PlutusTx.Prelude
import           Ledger                     (Address, DataScript (DataScript), PendingTx, PubKey,
                                             RedeemerScript (RedeemerScript), ValidatorScript (ValidatorScript),
                                             applyScript, compileScript, scriptAddress, lifted, pendingTxValidRange)
import qualified Ledger.Interval           as Interval
import           Ledger.Value               (Value)
import qualified Ledger.Validation         as V
import           Ledger.Slot                (Slot, SlotRange)
import qualified Ledger.Ada                as Ada
import           Playground.Contract
import           Wallet                     (MonadWallet, WalletAPI, WalletDiagnostics, collectFromScript, ownPubKey,
                                             defaultSlotRange, payToScript_, startWatching, logMsg)
import qualified Wallet                    as W
import           Wallet.Emulator           (Wallet)
import qualified Wallet.Emulator           as EM


data Commitment = Commitment
    { commitmentDeadline :: Slot
    , commitmentWitnesses :: [PubKey]
    , owner :: PubKey
    } deriving (Generic, ToJSON, FromJSON, ToSchema)
PlutusTx.makeLift ''Commitment

mkCommitment :: Slot -> [Wallet] -> Wallet -> Commitment
mkCommitment ddl witnessWallets ownerWallet =
    Commitment
        { commitmentDeadline = ddl
        , commitmentWitnesses = fmap EM.walletPubKey witnessWallets
        , owner = EM.walletPubKey ownerWallet
        }
        
votingRange :: Commitment -> SlotRange
votingRange c =
    W.intervalFrom (commitmentDeadline c)

data WitnessVote = Confirm | Deny
    deriving (Generic, ToJSON, FromJSON, ToSchema)
    
PlutusTx.makeLift ''WitnessVote

type WitnessValidator = PubKey -> PendingTx -> Bool

validVote :: Commitment -> WitnessValidator
validVote commitment witness ptx =
    -- Check that the commitment deadline is already due
    Interval.contains (votingRange commitment) (pendingTxValidRange ptx)
    -- check that the witness is actually part of the commitment
    && witness `elem` (commitmentWitnesses commitment)
    -- Check that the vote is signed by the witness
    && (ptx `V.txSignedBy` witness)
    
votingScript :: Commitment -> ValidatorScript
votingScript c  = ValidatorScript $
    $$(Ledger.compileScript [|| validVote ||])
        `Ledger.applyScript`
            Ledger.lifted c
            
-- | The address of a [[Commitment]]
commitmentAddress :: Commitment -> Ledger.Address
commitmentAddress = Ledger.scriptAddress . votingScript

-- | Helper function used to build the DataScript.
mkDataScript :: Slot -> [Wallet] -> Wallet -> DataScript
mkDataScript ddl witnesses owner =
    DataScript $ lifted $ mkCommitment ddl witnesses owner

-- | The "publish" contract endpoint.
publish :: MonadWallet m => Slot -> [Wallet] -> Wallet -> Value -> m ()
publish ddl witnessWallets ownerWallet lockedFunds =
    payToScript_ defaultSlotRange (commitmentAddress $ mkCommitment ddl witnessWallets ownerWallet) lockedFunds (mkDataScript ddl witnessWallets ownerWallet)
    
contribute :: MonadWallet m => Slot -> [Wallet] -> Wallet -> WitnessVote -> m ()
contribute ddl witnessWallets ownerWallet vote = do
    ownPK <- ownPubKey
    let ds = DataScript $ Ledger.lifted ownPK
        range = W.interval 1 ddl
    payToScript_ range (commitmentAddress $ mkCommitment ddl witnessWallets ownerWallet) (Ada.adaValueOf 0) ds
    
    logMsg "Submitted vote"

$(mkFunctions ['publish, 'contribute])

Simulation.json

[0,[{"wallets":[{"simulatorWalletWallet":{"getWallet":1},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},{"simulatorWalletWallet":{"getWallet":2},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}}],"signatures":[{"functionName":"publish","argumentSchema":[{"contents":[["getSlot",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaArray"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},{"tag":"FormSchemaValue"}]},{"functionName":"contribute","argumentSchema":[{"contents":[["getSlot",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaArray"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},{"contents":["Confirm","Deny"],"tag":"FormSchemaRadio"}]},{"functionName":"payToWallet_","argumentSchema":[{"tag":"FormSchemaValue"},{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"}]}],"currencies":[{"knownTokens":[{"unTokenName":""}],"hash":"","friendlyName":"Ada"}],"actions":[{"simulatorWallet":{"simulatorWalletWallet":{"getWallet":1},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},"functionSchema":{"functionName":"publish","argumentSchema":[{"contents":[["getSlot",{"contents":2,"tag":"FormInt"}]],"tag":"FormObject"},{"contents":[{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},[{"contents":[["getWallet",{"contents":2,"tag":"FormInt"}]],"tag":"FormObject"}]],"tag":"FormArray"},{"contents":[["getWallet",{"contents":1,"tag":"FormInt"}]],"tag":"FormObject"},{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},2]]]],"tag":"FormValue"}]},"tag":"Action"},{"blocks":2,"tag":"Wait"},{"simulatorWallet":{"simulatorWalletWallet":{"getWallet":2},"simulatorWalletBalance":{"getValue":[[{"unCurrencySymbol":""},[[{"unTokenName":""},10]]]]}},"functionSchema":{"functionName":"contribute","argumentSchema":[{"contents":[["getSlot",{"contents":2,"tag":"FormInt"}]],"tag":"FormObject"},{"contents":[{"contents":[["getWallet",{"tag":"FormSchemaInt"}]],"tag":"FormSchemaObject"},[{"contents":[["getWallet",{"contents":2,"tag":"FormInt"}]],"tag":"FormObject"}]],"tag":"FormArray"},{"contents":[["getWallet",{"contents":1,"tag":"FormInt"}]],"tag":"FormObject"},{"contents":[["Confirm","Deny"],"Confirm"],"tag":"FormRadio"}]},"tag":"Action"}]}]]