+++ /dev/null
-/*
- * This file is part of the libsigrok project.
- *
- * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "protocol.h"
-
-#define MAX_PACKET_LEN 22
-
-/* Flags passed from the DMM. */
-struct brymen_flags {
- gboolean is_low_batt, is_decibel, is_duty_cycle, is_hertz, is_amp;
- gboolean is_beep, is_ohm, is_fahrenheit, is_celsius, is_capacitance;
- gboolean is_diode, is_volt, is_dc, is_ac;
-};
-
-struct bm850_command {
- uint8_t dle;
- uint8_t stx;
- uint8_t cmd;
- uint8_t arg[2];
- uint8_t checksum;
- uint8_t dle2;
- uint8_t etx;
-};
-
-struct brymen_header {
- uint8_t dle;
- uint8_t stx;
- uint8_t cmd;
- uint8_t len;
-};
-
-struct brymen_tail {
- uint8_t checksum;
- uint8_t dle;
- uint8_t etx;
-};
-
-/*
- * We only have one command because we only support the BM-857. However, the
- * driver is easily extensible to support more models, as the protocols are
- * very similar.
- */
-enum {
- BM_CMD_REQUEST_READING = 0x00,
-};
-
-static int bm_send_command(uint8_t command, uint8_t arg1, uint8_t arg2,
- struct sr_serial_dev_inst *serial)
-{
- struct bm850_command cmdout;
- int written;
-
- cmdout.dle = 0x10;
- cmdout.stx = 0x02;
- cmdout.cmd = command;
- cmdout.arg[0] = arg1;
- cmdout.arg[1] = arg2;
- cmdout.checksum = arg1 ^ arg2;
- cmdout.dle2 = 0x10;
- cmdout.etx = 0x03;
-
- /* TODO: How to compute the checksum? Hardware seems to ignore it. */
-
- /* Request reading. */
- written = serial_write(serial, &cmdout, sizeof(cmdout));
- if (written != sizeof(cmdout))
- return SR_ERR;
-
- return SR_OK;
-}
-
-SR_PRIV int brymen_packet_request(struct sr_serial_dev_inst *serial)
-{
- return bm_send_command(BM_CMD_REQUEST_READING, 0, 0, serial);
-}
-
-SR_PRIV int brymen_packet_length(const uint8_t *buf, int *len)
-{
- struct brymen_header *hdr;
- int packet_len;
- size_t buflen;
-
- buflen = *len;
- hdr = (void *)buf;
-
- /* Did we receive a complete header yet? */
- if (buflen < sizeof(*hdr))
- return PACKET_NEED_MORE_DATA;
-
- if (hdr->dle != 0x10 || hdr->stx != 0x02)
- return PACKET_INVALID_HEADER;
-
- /* Our packet includes the header, the payload, and the tail. */
- packet_len = sizeof(*hdr) + hdr->len + sizeof(struct brymen_tail);
-
- /* In case we pick up an invalid header, limit our search. */
- if (packet_len > MAX_PACKET_LEN) {
- sr_spew("Header specifies an invalid payload length: %i.",
- hdr->len);
- return PACKET_INVALID_HEADER;
- }
-
- *len = packet_len;
- sr_spew("Expecting a %d-byte packet.", *len);
- return PACKET_HEADER_OK;
-}
-
-SR_PRIV gboolean brymen_packet_is_valid(const uint8_t *buf)
-{
- struct brymen_header *hdr;
- struct brymen_tail *tail;
- int i;
- uint8_t chksum = 0;
- uint8_t *payload;
-
- payload = (uint8_t *)(buf + sizeof(struct brymen_header));
-
- hdr = (void *)buf;
- tail = (void *)(payload + hdr->len);
-
- for (i = 0; i< hdr->len; i++)
- chksum ^= payload[i];
-
- if (tail->checksum != chksum) {
- sr_dbg("Packet has invalid checksum 0x%.2x. Expected 0x%.2x.",
- chksum, tail->checksum);
- return FALSE;
- }
-
- return TRUE;
-}
-
-static int parse_value(const char *strbuf, int len, float *floatval)
-{
- int s, d;
- char str[32];
-
- if (strstr(strbuf, "OL")) {
- sr_dbg("Overlimit.");
- *floatval = INFINITY;
- return SR_OK;
- }
-
- memset(str, 0, sizeof(str));
- /* Spaces may interfere with parsing the exponent. Strip them. */
- for (s = 0, d = 0; s < len; s++) {
- if (strbuf[s] != ' ')
- str[d++] = strbuf[s];
- }
- if (sr_atof_ascii(str, floatval) != SR_OK)
- return SR_ERR;
-
- return SR_OK;
-}
-
-static void parse_flags(const uint8_t *buf, struct brymen_flags *info)
-{
- info->is_low_batt = (buf[4 + 3] & (1 << 7)) != 0;
-
- info->is_decibel = (buf[4 + 1] & (1 << 5)) != 0;
- info->is_duty_cycle = (buf[4 + 1] & (1 << 3)) != 0;
- info->is_hertz = (buf[4 + 1] & (1 << 2)) != 0;
- info->is_amp = (buf[4 + 1] & (1 << 1)) != 0;
- info->is_beep = (buf[4 + 1] & (1 << 0)) != 0;
-
- info->is_ohm = (buf[4 + 0] & (1 << 7)) != 0;
- info->is_fahrenheit = (buf[4 + 0] & (1 << 6)) != 0;
- info->is_celsius = (buf[4 + 0] & (1 << 5)) != 0;
- info->is_diode = (buf[4 + 0] & (1 << 4)) != 0;
- info->is_capacitance = (buf[4 + 0] & (1 << 3)) != 0;
- info->is_volt = (buf[4 + 0] & (1 << 2)) != 0;
- info->is_dc = (buf[4 + 0] & (1 << 1)) != 0;
- info->is_ac = (buf[4 + 0] & (1 << 0)) != 0;
-}
-
-SR_PRIV int brymen_parse(const uint8_t *buf, float *floatval,
- struct sr_datafeed_analog *analog, void *info)
-{
- struct brymen_flags flags;
- struct brymen_header *hdr;
- uint8_t *bfunc;
- int asciilen;
-
- (void)info;
-
- hdr = (void *)buf;
- bfunc = (uint8_t *)(buf + sizeof(struct brymen_header));
-
- analog->mqflags = 0;
-
- /* Give some debug info about the package. */
- asciilen = hdr->len - 4;
- sr_dbg("DMM flags: %.2x %.2x %.2x %.2x",
- bfunc[3], bfunc[2], bfunc[1], bfunc[0]);
- /* Value is an ASCII string. */
- sr_dbg("DMM packet: \"%.*s\"", asciilen, bfunc + 4);
-
- parse_flags(buf, &flags);
- if (parse_value((const char *)(bfunc + 4), asciilen, floatval) != SR_OK)
- return SR_ERR;
-
- if (flags.is_volt) {
- analog->mq = SR_MQ_VOLTAGE;
- analog->unit = SR_UNIT_VOLT;
- }
- if (flags.is_amp) {
- analog->mq = SR_MQ_CURRENT;
- analog->unit = SR_UNIT_AMPERE;
- }
- if (flags.is_ohm) {
- if (flags.is_beep)
- analog->mq = SR_MQ_CONTINUITY;
- else
- analog->mq = SR_MQ_RESISTANCE;
- analog->unit = SR_UNIT_OHM;
- }
- if (flags.is_hertz) {
- analog->mq = SR_MQ_FREQUENCY;
- analog->unit = SR_UNIT_HERTZ;
- }
- if (flags.is_duty_cycle) {
- analog->mq = SR_MQ_DUTY_CYCLE;
- analog->unit = SR_UNIT_PERCENTAGE;
- }
- if (flags.is_capacitance) {
- analog->mq = SR_MQ_CAPACITANCE;
- analog->unit = SR_UNIT_FARAD;
- }
- if (flags.is_fahrenheit) {
- analog->mq = SR_MQ_TEMPERATURE;
- analog->unit = SR_UNIT_FAHRENHEIT;
- }
- if (flags.is_celsius) {
- analog->mq = SR_MQ_TEMPERATURE;
- analog->unit = SR_UNIT_CELSIUS;
- }
- if (flags.is_capacitance) {
- analog->mq = SR_MQ_CAPACITANCE;
- analog->unit = SR_UNIT_FARAD;
- }
-
- /*
- * The high-end Brymen models have a configurable reference impedance.
- * When the reference impedance is changed, the DMM sends one packet
- * with the value of the new reference impedance. Both decibel and ohm
- * flags are set in this case, so we must be careful to correctly
- * identify the value as ohm, not dBmW.
- */
- if (flags.is_decibel && !flags.is_ohm) {
- analog->mq = SR_MQ_POWER;
- analog->unit = SR_UNIT_DECIBEL_MW;
- /*
- * For some reason, dBm measurements are sent by the multimeter
- * with a value three orders of magnitude smaller than the
- * displayed value.
- */
- *floatval *= 1000;
- }
-
- if (flags.is_diode)
- analog->mqflags |= SR_MQFLAG_DIODE;
- /* We can have both AC+DC in a single measurement. */
- if (flags.is_ac)
- analog->mqflags |= SR_MQFLAG_AC;
- if (flags.is_dc)
- analog->mqflags |= SR_MQFLAG_DC;
-
- if (flags.is_low_batt)
- sr_info("Low battery!");
-
- return SR_OK;
-}
projects / libsigrok.git / blobdiff