Swapbox overview

Hardware

Electronics

Type	Component
Computer board	Raspberry Pi 4 model B 8GB
Cash-in device	Innovative technology NV10
Cash-out device	ICT group NDE-1000
Screen	10.1" IPS Industrial Touchscreen Display for Raspberry Pi
Camera (to scan QR codes)	16MP IMX519 Autofocus Camera Module
Power supply 1	12V DC power supply unit
Power supply 2	5V DC power supply unit

Enclosure & mounting

Enclosure parts are made of thick extruded aluminum panels (1.5cm) and strong steel plates (2mm, 3mm for the Top panel). The parts are very easy to manufacture by any metal worker.

Mounting parts are 3D printed, making them easy to replace and adapt for other electronics.

Software

Swapbox interface

The Swapbox interface is the software run on the Raspberry Pi on the machine, allowing users to interact with the machine. It is also used by the operator to:

1. Change settings
   1. Connect to deployed smart contract
   2. Set an internet connection
   3. Set / reset notes count (when changing cash cassette)
   4. Max amounts
2. Check status
   1. Internet
   2. Paper (Printer opt-in only)
   3. Note
3. Diagnostics
   1. Manual note payout
   2. Printer linefeed (Printer opt-in only) Kivy for performance & simplicity

Note
Swapbox does not provide a KYC software module. If the operator wishes to add KYC to his machines, he must need to add him manually.

Admin dApp

The Admin dApp is the backend software of Swapbox. It allows the operator to interact with the smart contract described below. To ensure maximum censorship resistance, the app will be hosted on Swarm, a decentralized hosting service.

Smart contracts

Swapbox has 3 distinct smart contracts:

1. SwapboxUniswapV3
   The contract swapping stablecoins for user desired tokens for buy transaction, and vice versa for sells, on Uniswap.
2. Swapbox
   Main Swapbox contract, used to:
   1. Hold stablecoins and accrued fees
   2. Call SwapboxUniswapV2 during a transaction
   3. Add and remove tokens from available tokens
   4. Update buy and sell fees.
3. Pricefeed
   1. Get the price of the traded asset from the Uniswap pair.