NVType C Reference¶

A file for organising configuration data stored in Non-Volatile memory.

These data are read by several parts of the encoder, where it is declared as an external global variable.

The variable definition depends on how the encoder is being run:

When running under CFFI (see PyEncoder) nv is defined in nvtype.c
When running as part of a larger project (e.g. the cupl Tag firmware) nv must be defined elsewhere.

The intention is for nv to occupy the 512 byte MSP430 information FRAM.

Date: 6 Aug 2018
Author: Malcolm Mackay
Copyright: Plotsensor Ltd.

Defines

SERIAL_LENBYTES¶: Length of the tag serial string in bytes.

SECKEY_LENBYTES¶: Length of the secret key used for HMAC-MD5 in bytes.

BASEURL_LENBYTES¶: Maximum length of the base URL string in bytes.

SMPLINT_LENBYTES¶: Length of the sample interval (minutes) integer in bytes.

VFMTINT_LENBYTES¶: VFmt character array length in bytes.

FORMAT_ASCII_MAXLEN¶: Maximum length of the format ASCII string.

MINVOLTAGEMV_ASCII_MAXLEN¶: Maximum length of the minimum voltage (mV) ASCII string.

SMPLINTERVAL_ASCII_MAXLEN¶: Maximum length of the sample interval string.

Typedefs

typedef struct nvstruct nv_t¶: Structure to hold configuration data held in non-volatile memory.

struct nvstruct¶

#include <nvtype.h>

Structure to hold configuration data held in non-volatile memory.

Public Members

char serial[SERIAL_LENBYTES]¶: Alphanumeric serial of the tag running the cupl encoder.

char seckey[SECKEY_LENBYTES]¶: Secret key string used for HMAC-MD5.

char smplintervalmins[SMPLINT_LENBYTES]¶: Time interval betweeen samples in minutes.

char baseurl[BASEURL_LENBYTES]¶: URL of the cupl Web Application frontend.

char format¶: Codec format byte.

unsigned int minvoltagemv¶: Minimum startup voltage in mV.

unsigned int usehmac¶: When non-zero enable HMAC otherwise use MD5 only.

unsigned int httpsdisable¶: When non-zero use HTTP in the URL otherwise use HTTPS.

unsigned int sleepintervaldays¶: Number of days to wait without scans before putting the cupl Tag into deep sleep mode.

unsigned int allwritten¶: When non-zero all required NV parameters have been set.

unsigned int resetsperloop¶: Incremented each time the tag microcontroller resets. Zeroed when the circular buffer loops around (see ds_looparound).

unsigned int resetsalltime¶: Incremented each time the tag microcontroller resets.

Functions

void fram_write_enable(): Enable writes to FRAM. Should be defined in the processor-specific cuplTag project.

void fram_write_disable(): Disable writes to FRAM. Should be defined in the processor-specific cuplTag project.

Variables

nv_t nv = {.serial="AAAACCCC", .seckey="AAAACCCC"}: Externally defined parameters stored in non-volatile memory.