Receipt capture and Tesseract OCR processing device

We require a skilled developer with knowledge on on linux. main goal of the project : We are looking to do a tapping device that will be plugged between a POS (or cashregister) and POS printer behing merchants desk. POS can send print to printer by USB, RS232 or IP. What we need to do : 1- capture a print job sent from a POS, 2- prehook and posthook print : we want to be able to add QRCODE or Coupon before or at the bottom of the receipt captured. Check this 3- after adding Posthook job, print the receipt to the POS printer with the additional information 4- do OCR using tesseract to find amount on the ticket, and put it on a database, waiting to be consulted by another device by trough a rest api. 5 - send the raw data captured, to a remote server where he will be processed. Setup : 1 - The box that we need to use will be a linux based mini board like odroid C1+ or higher. the linux box will not have display connected on it, so the developper has to permet a process for the out of box first setup, like a router that is set up by http. In other word, our customer has to succeed easily to connect the device to his wifi, and internet. 2 - One connected to the internet, the box will have to take his parameter from file sent by an existing server that manage other device. any other pragmatics technics proposals are welcome to acheive this. More details will be made available to the developer that is awarded the project. We will ask you to write the final specification.