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Merged
linguini1 merged 1 commit into from
Jul 14, 2025
Merged

parallelizing ads1115 conversion triggers #97

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4 changes: 4 additions & 0 deletions .gitignore
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Original file line number Diff line number Diff line change
Expand Up @@ -7,3 +7,7 @@ Make.dep
.kconfig
/Kconfig
*.built

# Dev tools
compile_commands.json
.cache/
114 changes: 77 additions & 37 deletions pad_server/src/telemetry.c
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Original file line number Diff line number Diff line change
Expand Up @@ -338,16 +338,14 @@ static void sensor_telemetry(telemetry_args_t *args, telemetry_sock_t *telem) {
#endif

for (;;) {

/* We hopefully won't go beyond 32 sensors */

struct iovec pkt[(32) * 2];
struct iovec pkt[(32) * 2]; /* 32 possible measurements, headers and bodies */
int sensor_count = 0;

struct timespec time_t;
uint32_t time_ms;

header_p headers[32];

/* All possible sensor bodies */

union {
pressure_p pressure;
mass_p mass;
Expand All @@ -360,39 +358,78 @@ static void sensor_telemetry(telemetry_args_t *args, telemetry_sock_t *telem) {
struct adc_msg_s sample;
adc_channel_t *channel;

for (int i = 0; i < arr_len(adc_devices); i++) {
/* For each of the possible 4 channels an ADS1115 ADC can have, we loop */

if (adc_devices[i].fd < 0) {
continue;
}
for (int j = 0; j < 4; j++) {

for (int j = 0; j < adc_devices[i].n_channels; j++) {
/* For each ADC, we loop and we trigger a conversion on their `j`th channel */

channel = &adc_devices[i].channels[j];
for (int i = 0; i < arr_len(adc_devices); i++) {

/* If this ADC has an invalid file descriptor, skip it.
* If the ADC does not have a `j`th channel, skip it.
*/

if (adc_devices[i].fd < 0 || j >= adc_devices[i].n_channels) {
continue;
}

/* Read specifically the channel of interest */
/* We have a valid ADC with a channel `j`. Trigger a conversion on this channel for this ADC */

channel = &adc_devices[i].channels[j];
sample.am_channel = channel->channel_num;
err = ioctl(adc_devices[i].fd, ANIOC_ADS1115_READ_CHANNEL, &sample);
if (err < 0) {
herr("Couldn't read ADC channel %d: %d\n", i, errno);
continue; /* Skip channels with errors */

err = ioctl(adc_devices[i].fd, ANIOC_ADS1115_TRIGGER_CONVERSION, &sample);
if (err) {
herr("Couldn't trigger ADC channel %d: %d\n", channel->channel_num, errno);
continue;
}
}

/* For each channel of data we find the corresponding information */
/* Now, for each ADC again, get the completed conversion result from channel `j` and put it in the packet.
*/

int32_t sensor_val = 0;
err = adc_sensor_val_conversion(channel, sample.am_data, &sensor_val);
for (int i = 0; i < arr_len(adc_devices); i++) {

headers[sensor_count] = (header_p){.type = TYPE_TELEM, .subtype = channel->type};
pkt[sensor_count * 2] =
(struct iovec){.iov_base = &headers[sensor_count], .iov_len = sizeof(headers[sensor_count])};
/* If this ADC has an invalid file descriptor, skip it.
* If the ADC does not have a `j`th channel, skip it.
*/

if (adc_devices[i].fd < 0 || j >= adc_devices[i].n_channels) {
continue;
}

channel = &adc_devices[i].channels[j];
sample.am_channel = channel->channel_num;
err = ioctl(adc_devices[i].fd, ANIOC_ADS1115_READ_CHANNEL_NO_CONVERSION, &sample);

if (err) {
herr("Couldn't read ADC channel %d: %d\n", channel->channel_num, errno);
continue;
}

/* Get an exact time stamp */
/* Get an exact time stamp for the data body */

clock_gettime(CLOCK_MONOTONIC, &time_t);
time_ms = time_t.tv_sec * 1000 + time_t.tv_nsec / 1000000;

/* Now that we have the voltage from the ADC, convert it to a real measurement. */

int32_t sensor_val = 0;
err = adc_sensor_val_conversion(channel, sample.am_data, &sensor_val);
if (err) {
herr("Couldn't convert value from ADC channel %d: %d\n", i, err);
continue;
}

/* Put the converted value in the packet */

headers[sensor_count] = (header_p){.type = TYPE_TELEM, .subtype = channel->type};
pkt[sensor_count * 2] = (struct iovec){
.iov_base = &headers[sensor_count],
.iov_len = sizeof(headers[sensor_count]),
};

switch (channel->type) {
case TELEM_PRESSURE:
bodies[sensor_count].pressure =
Expand Down Expand Up @@ -465,28 +502,31 @@ static void sensor_telemetry(telemetry_args_t *args, telemetry_sock_t *telem) {

time_ms = sensor_temp[i].data.timestamp / 1000;
headers[sensor_count] = (header_p){.type = TYPE_TELEM, .subtype = TELEM_TEMP};
bodies[sensor_count].temp = (temp_p){.time = time_ms,
.id = sensor_temp[i].sensor_id,
.temperature = sensor_temp[i].data.temperature * 1000};
pkt[sensor_count * 2] =
(struct iovec){.iov_base = &headers[sensor_count], .iov_len = sizeof(headers[sensor_count])};
pkt[sensor_count * 2 + 1] =
(struct iovec){.iov_base = &bodies[sensor_count].temp, .iov_len = sizeof(temp_p)};

bodies[sensor_count].temp = (temp_p){
.time = time_ms,
.id = sensor_temp[i].sensor_id,
.temperature = sensor_temp[i].data.temperature * 1000,
};
pkt[sensor_count * 2] = (struct iovec){
.iov_base = &headers[sensor_count],
.iov_len = sizeof(headers[sensor_count]),
};
pkt[sensor_count * 2 + 1] = (struct iovec){
.iov_base = &bodies[sensor_count].temp,
.iov_len = sizeof(temp_p),
};
sensor_count++;
}
}
#endif

/* Send the telemetry that was collected */

if (sensor_count > 0) {
struct msghdr msg = {
.msg_iov = pkt,
.msg_iovlen = sensor_count * 2,
};
struct msghdr msg = {.msg_iov = pkt, .msg_iovlen = sensor_count * 2};
telemetry_publish(telem, &msg);
} else {
herr("No sensor data to send\n");
usleep(1000000);
}
}
}
Expand Down
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