sibo-playground/code/inventory/README.md

inventory

A demo inventory application for the Psion Workabout MX: scan UPC barcodes, and (Phase 2) keep stock counts in a database file, adding stock or consuming it by scanning.

Written in PLIB C, built with the TopSpeed compiler (tsc /m scan).

Phases

• Phase 1 (this commit): scan and validate. Reads barcodes from the scanner and prints each one, flagging whether it is a valid UPC-A. Modules: upc (validation), bcode (scanner input), scan (the demo).
• Phase 2 (next): inventory database. A DBF file keyed on UPC holding a quantity and a name. Scan to add stock (increment, or create on first sight), scan to consume by a quantity unit. Built on the SIBO Dbf* API.

Build

tsc /m scan

Produces scan.img. scan.pr compiles upc.c, bcode.c and scan.c and links them.

How the scanner is read

On the Workabout the barcode module decodes the label in hardware and sends the result as an RS232 stream, so there is no special barcode driver call: the app opens the serial port and reads it. The scanner is on the top internal slot, which is port D, so the device is TTY:D (bcode.c).

The scan loop is asynchronous: it waits on the scanner and the keyboard at the same time, so a scan is processed immediately and Esc quits at any point.

Things to confirm on the device

Because this cannot be compiled or run off-device, these points are written to the SDK docs but may need adjusting once you build and test:

• Serial line settings. bcodeOpen opens TTY:D with the default mode. If the scanner needs a specific baud/parity/framing, configure the channel with p_iow(chan, P_FSET, &config) (E_CONFIG, p_config.h) after opening.
• Terminator. BCODE_TERM in bcode.h is set to CR (0x0D), the common case. Change it if your scanner suffixes LF or something else.
• Esc key code. KEY_ESC in scan.c is 27; adjust if the console delivers a different code.
• CON: async read. Phase 1 reads single keystrokes asynchronously from CON:; if that behaves differently on your unit, the keyboard handling in scan.c is where to look.