Lesson 13 - Wrong DAI price wih the Data Feed

[SebasAran16]

Hello,

I am creating this discussion to now if this what is happening to me is some kind of mistake from me or, in another hand, is an issue.

What happens is that when I am tryg to consoleLog the DAI/ETH price, I get another price, this: 634551646080931. When actually the ETH price is in 1580 rigth now, actually. This is my code:

async function getDaiPrice() {
    const daiEthPriceFeed = await ethers.getContractAt(
        "AggregatorV3Interface",
        "0x773616E4d11A78F511299002da57A0a94577F1f4"
    );
    const price = (await daiEthPriceFeed.latestRoundData())[1];
    console.log(`The DAI price is: ${price.toString()}`);
    return price;

When changing the return value of the function in: const price = (await daiEthPriceFeed.latestRoundData())[1]; to [2]/[3], it gives me a close value: 1662327363, but in the Interface those values are the startedAt and updatedAt and the answer is not accurate enough.

Thank you very much, hope that somebody knows that more about this help me with this.

[alymurtazamemon]

@SebasAran16 This is the DAI/ETH price without conversion. The starting 4 digits tells the exact price, and after that it includes the additional digits. After getting it, we convert it to only DAI and WEI amount.

// * convert to dai amount user can borrow.
  const amountDaiToBorrow =
    availableBorrowsETH.toString() * 0.95 * (1 / daiPrice.toNumber());
  console.log(`You can borrow ${amountDaiToBorrow.toString()} DAI`);

  // * convert to wei
  const amountToDaiBorrowWie = ethers.utils.parseEther(
    amountDaiToBorrow.toString()
  );

[SebasAran16]

Yeah, but the numbers I am getting are 6345 (those are the first 4) when Patrick was given the correct price (at the time of recording). Could I be doing something wrong?

[alymurtazamemon]

@SebasAran16 I am also getting 6410

[alymurtazamemon]

@SebasAran16 Price gets updated with time when Patrick recorded video, ETH price was $4000 and now it $1500

[SebasAran16]

Ok, thank you so much!

[rguillou118]

I guess with price feed of 0x773616E4d11A78F511299002da57A0a94577F1f4, we have the inverse price of ETH/USD (1 DAI = x ETH, and not 1 ETH = y DAI)

[SkyHustle]

This was pretty confusing for me as well, until I realized that the answer is essentially how much ETH you could buy for 1 DAI.
Here's a code snippet that you could use to help clear up the confusion.

async function getDaiPrice() {
    // don't need to connect to deployer account since we are not sending any txs
    const daiEthPriceFeed = await ethers.getContractAt(
        "AggregatorV3Interface",
        networkConfig[network.config.chainId].daiEthPriceFeed
    )
    const price = (await daiEthPriceFeed.latestRoundData())[1] // answer
    console.log(`This how much ETH you could buy with 1 DAI ${ethers.utils.formatEther(price)}`)
    const ethPriceInDai = ethers.utils.parseEther("1").div(price)
    console.log(`This how much DAI you could buy with 1 ETH i.e. price of 1 ETH ${ethPriceInDai}`)
    return price
}