how to swap Token for ETH with swapExactTokensForETH() using UniswapV2Router02 Contract

korchix picture korchix · Feb 13, 2021 · Viewed 9.4k times · Source

i'm traying to swap some DAI for ETH on the Ropsten Network using the UniswapV2Router02 on Etherscan (Ropsten Test Network).

DAI Address on Ropsten = 0xad6d458402f60fd3bd25163575031acdce07538d WETH = 0xc778417E063141139Fce010982780140Aa0cD5Ab

in my Wallet i have 2000 DAI (Ropsten)

but when i put the data there. like this: enter image description here

Metamask shows that there is an Error thrown by the Contract. So i might be missing something or am'i doing it wrong.

enter image description here

can please someone help and show me how can i make a successful transaction there ?

Answer

korchix picture korchix · Feb 13, 2021

i got this to work. if someone is interested to know how, here is what i have done.

1- amountIn should be in 10^18, that means 100 was wrong, it should be 100x10^18 = 100000000000000000000

2- first i had to approve the UniswapRouterAddress to spend this 100 DAI. so on the DAI contract Address i had to put the data like this:

enter image description here

after that i was able t swap the 100 DAI for ETH (as much as 100 DAI is worth of ETH)