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hantek-6xxx: properly set encoding digits

This commit is contained in:
Aurelien Jacobs 2016-08-24 00:55:12 +02:00 committed by Uwe Hermann
parent 545101338a
commit 1e1fdbc994
1 changed files with 34 additions and 30 deletions
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64
src/hardware/hantek-6xxx/api.c
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@ -18,6 +18,7 @@
*/
#include <config.h>
#include <math.h>
#include "protocol.h"
/* Max time in ms before we want to check on USB events */
@ -561,55 +562,58 @@ static void send_chunk(struct sr_dev_inst *sdi, unsigned char *buf,
struct sr_analog_meaning meaning;
struct sr_analog_spec spec;
struct dev_context *devc = sdi->priv;
int num_channels, data_offset, i;
GSList *channels = devc->enabled_channels;
const float ch1_bit = RANGE(0) / 255;
const float ch2_bit = RANGE(1) / 255;
const float ch1_center = RANGE(0) / 2;
const float ch2_center = RANGE(1) / 2;
const gboolean ch1_ena = !!devc->ch_enabled[0];
const gboolean ch2_ena = !!devc->ch_enabled[1];
const float ch_bit[] = { RANGE(0) / 255, RANGE(1) / 255 };
const float ch_center[] = { RANGE(0) / 2, RANGE(1) / 2 };
sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
num_channels = (ch1_ena && ch2_ena) ? 2 : 1;
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
analog.meaning->channels = devc->enabled_channels;
analog.num_samples = num_samples;
analog.meaning->mq = SR_MQ_VOLTAGE;
analog.meaning->unit = SR_UNIT_VOLT;
analog.meaning->mqflags = 0;
analog.data = g_try_malloc(analog.num_samples * sizeof(float) * num_channels);
analog.data = g_try_malloc(num_samples * sizeof(float));
if (!analog.data) {
sr_err("Analog data buffer malloc failed.");
devc->dev_state = STOPPING;
return;
}
data_offset = 0;
for (i = 0; i < num_samples; i++) {
/*
* The device always sends data for both channels. If a channel
* is disabled, it contains a copy of the enabled channel's
* data. However, we only send the requested channels to
* the bus.
*
* Voltage values are encoded as a value 0-255, where the
* value is a point in the range represented by the vdiv
* setting. There are 10 vertical divs, so e.g. 500mV/div
* represents 5V peak-to-peak where 0 = -2.5V and 255 = +2.5V.
*/
if (ch1_ena)
((float *)analog.data)[data_offset++] = (ch1_bit * *(buf + i * 2) - ch1_center);
if (ch2_ena)
((float *)analog.data)[data_offset++] = (ch2_bit * *(buf + i * 2 + 1) - ch2_center);
}
for (int ch = 0; ch < 2; ch++) {
if (!devc->ch_enabled[ch])
continue;
sr_session_send(sdi, &packet);
float vdivlog = log10f(ch_bit[ch]);
int digits = -(int)vdivlog + (vdivlog < 0.0);
analog.encoding->digits = digits;
analog.spec->spec_digits = digits;
analog.meaning->channels = g_slist_append(NULL, channels->data);
for (int i = 0; i < num_samples; i++) {
/*
* The device always sends data for both channels. If a channel
* is disabled, it contains a copy of the enabled channel's
* data. However, we only send the requested channels to
* the bus.
*
* Voltage values are encoded as a value 0-255, where the
* value is a point in the range represented by the vdiv
* setting. There are 10 vertical divs, so e.g. 500mV/div
* represents 5V peak-to-peak where 0 = -2.5V and 255 = +2.5V.
*/
((float *)analog.data)[i] = ch_bit[ch] * *(buf + i * 2 + ch) - ch_center[ch];
}
sr_session_send(sdi, &packet);
g_slist_free(analog.meaning->channels);
channels = channels->next;
}
g_free(analog.data);
}