52 lines
2.1 KiB
Markdown
52 lines
2.1 KiB
Markdown
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# inventory
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A demo inventory application for the Psion Workabout MX: scan UPC barcodes, and
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(Phase 2) keep stock counts in a database file, adding stock or consuming it by
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scanning.
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Written in PLIB C, built with the TopSpeed compiler (`tsc /m scan`).
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## Phases
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- **Phase 1 (this commit): scan and validate.** Reads barcodes from the scanner
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and prints each one, flagging whether it is a valid UPC-A.
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Modules: `upc` (validation), `bcode` (scanner input), `scan` (the demo).
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- **Phase 2 (next): inventory database.** A DBF file keyed on UPC holding a
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quantity and a name. Scan to add stock (increment, or create on first sight),
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scan to consume by a quantity unit. Built on the SIBO `Dbf*` API.
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## Build
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```
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tsc /m scan
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```
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Produces `scan.img`. `scan.pr` compiles `upc.c`, `bcode.c` and `scan.c` and
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links them.
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## How the scanner is read
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On the Workabout the barcode module decodes the label in hardware and sends the
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result as an RS232 stream, so there is no special barcode driver call: the app
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opens the serial port and reads it. The scanner is on the top internal slot,
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which is port **D**, so the device is `TTY:D` (`bcode.c`).
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The scan loop is asynchronous: it waits on the scanner and the keyboard at the
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same time, so a scan is processed immediately and Esc quits at any point.
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## Things to confirm on the device
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Because this cannot be compiled or run off-device, these points are written to
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the SDK docs but may need adjusting once you build and test:
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- **Serial line settings.** `bcodeOpen` opens `TTY:D` with the default mode. If
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the scanner needs a specific baud/parity/framing, configure the channel with
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`p_iow(chan, P_FSET, &config)` (E_CONFIG, `p_config.h`) after opening.
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- **Terminator.** `BCODE_TERM` in `bcode.h` is set to CR (`0x0D`), the common
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case. Change it if your scanner suffixes LF or something else.
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- **Esc key code.** `KEY_ESC` in `scan.c` is `27`; adjust if the console
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delivers a different code.
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- **`CON:` async read.** Phase 1 reads single keystrokes asynchronously from
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`CON:`; if that behaves differently on your unit, the keyboard handling in
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`scan.c` is where to look.
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