Your machine can connect to an exchange so that bitcoin is automatically purchased at market rates with each bill that's inserted. In this way the price volatility of cryptocurrency is mitigated.
Bitstamp trading is supported for Bitcoin, Bitcoin Cash, Ethereum, and Litecoin on all fiat currencies.
Flow with trading
When linked to an exchange, the flow is: user inserts bills, machine places buy order with each bill inserted, bitcoins are sent from the machine's hot wallet to the user. The module will purchase the same amount of bitcoins that is dispensed to the user.
For security purposes, the admin does not initiate a withdrawal of bitcoin from your trading account to your hot wallet. You should periodically top up your machine's wallet by sending it the coins which are purchased on Bitstamp.
Please note: Though trading will occur with the machine on any currency at Bitstamp's USD market rates, their ticker API currently only supports USD or EUR. Please set your price source to any option other than Bitstamp if using another currency.
Creating an API key
To trade on Bitstamp, create a new API key from within your account. Go to Security, then API Access.
Click on 'New API key', then check the 'Account balance' and 'Buy limit order' permission boxes. For the security of your account balance, do not enable any others.
Click 'Generate key'. In the screen that follows, copy the Key and Secret fields.
On Bitstamp, click 'Activate' next to your secret key. Check your email for an activation link and follow it to enable.
Configuring the admin
In the 'Third Party Services / Bitstamp' panel of the admin, enter your Bitstamp Client ID, key, and secret into the appropriate fields and click Submit:
Then navigate to the 'Global Settings / Wallet Settings' panel for Bitcoin. Select Bitstamp from the Exchange drop-down list. If using USD or EUR, select the Bitstamp ticker as well. Then click Submit.
Test trades by placing purchases at the machine using an amount greater than $5 USD (the minimum trade Bitstamp allows.)