qb64 subroutines for ascii com port communications

  • Status Closed
  • Budget $30 - $250 USD
  • Total Bids 4

Project Description

We have a controller that connects to the pc using the usb port using virtual com port. We have the drivers for the com port and need to use qb64 to communicate with the controller. QB64 is a modern version of quick basic or qbasic with more features and is available for download free of charge. Just google QB64. The subroutines are needed to be written using this program for testing and in house refinement.

The subroutines will have integer variables that need to be passed to the controller over the open com port in a specific order. We will create the data and the data has to be sent to the controller in ascii format. Each text line consists of the following: an ASCII colon character followed by a list of ASCII encoded integer command values followed by a terminating newline character. The command values will be variables that our program will create. The ASCII encoded command values are all interpreted as integer values and must be separated by either an ASCII comma character or an ASCII period character. Thus, legal command characters are: the colon, the comma, the period, the digits 0 through 9, and the new-line. Each ASCII packet is from 3 to 38 comma separated values. The command packet diagram is attached as a jpeg to this request. You will notice in the diagram that there is a checksum. This is not necessary and only needs to send a value of 0.

The controller uses 14-bit values to control our product. Since the protocol is based upon 8-bit values, the transmission of 14-bit values is achieved by sending two values each containing 7-bits of the 14-bit message. For multi-byte value transmission, the most-significant portion (MSB) is always sent first and the least-significant portion (LSB) is sent second. The MSB is composed of bits 7-13 and the LSB is composed of bits 0-6.

There are several commands with variable command values that need to be set up as subroutines to create the appropriate ascii character string to send out of the com port. We will provide the command set. Please let me know if you have any questions on this.


Jim Nordquist

Get free quotes for a project like this

Looking to make some money?

  • Set your budget and the timeframe
  • Outline your proposal
  • Get paid for your work

Hire Freelancers who also bid on this project

    • Forbes
    • The New York Times
    • Time
    • Wall Street Journal
    • Times Online