MQTT with Contiki OS

Try to refer to processors.wiki.ti.com/.../Cc26xx_contiki_ibm_cloud

Thanks! I have a doubt. The Contiki OS is written in C or C++?

It’s C.

Hi Yikay, I working with MQTT communication. I downloaded the PAHO eclipse libraries on Instant Contiki and added them to the contiki / apps folder to create an example. I added in the Makefile of hello-world APPS + = paho.mqtt.c and in the compilation not from errors, but it gives me "undefined reference to". What could it be?

I don't have experience to do such porting so I cannot help.

In contiki os, do we necessarily need processes in a code?

I couldn't understand your question.

In Contiki OS, the PROCESS_NAME, PROCESS_BEGIN and PROCESS_END can they not use?

No, I think you have to use them.

Hi YiKai, the library of MQTT that uses Contiki OS, supports the TLS1.2 connection?

If I remember correctly, Contiki OS only supports DTLS.

Ok Thanks. How can I add the address Ipv6 of sensor on list of Coap page?

I couldn’t understand your question.

I want to add the resource on CoAP page of Ipv6 address of device

Try to refer to sunmaysky.blogspot.tw/.../how-to-add-coap-resource-to-read-adc.html and do accordingly.

For to add the voice Ipv6 address of device?

Yikai, I want to see the string on web coap.

For example:

I open the CoAP of the device, core-discover, click on "text" for example and GET. I want read the string, not value. How can i do?

Basically, it’s similar to show value or string. I have show you an example so I suppose you should be able to revise on it accordingly.

I put the varible how char, but when I digit GET I see the number

I want to see the printf("Close heard") on CoAP

I don’t understand what you mean you want to see the printf("Close heard") on CoAP.

Yes, in this photo, I want "close heard" instead of 140. It's possible?

Yes

In the code that I sent you, there is something wrong? When I write this code, I see 140 but not close heard

I don't see you add coap resource like I did in sunmaysky.blogspot.tw/.../how-to-add-coap-resource-to-read-adc.html so I don't think your code would work.

Yes i did it!

I entered the value variable
I entered the DEMO SENSOR
I entered the reading publish
I entered the list add
I entered the process start
I entered the code I sent you

in the coap-server.c

I entered extern resources
I entered the rest activate

in the cc26xx-web-demo.h

I added the resource

in the res-sensor.c

I added the static void and the resource

Did I mistake something in the code I sent you before?

The code you attached just do printf when receiving from UART and I don't see you how you connect it to any coap resource.

1) cc26xx-web-demo.c I add:

#include "dev/cc26xx-uart.h"
"dev/serial-line.h"

PROCESS(test_serial_process, "Serial process");

static uint16_t valor;
static struct etimer et_cen;

DEMO_SENSOR(heard, CC26XX_WEB_DEMO_SENSOR_HEARD,
"Heard", "heard", "heard",
CC26XX_WEB_DEMO_UNIT_VOLT);

static char value;
char *buf;

if(heard_reading.publish) {
value = valor;
buf = heard_reading.converted;
memset(buf, 0, CC26XX_WEB_DEMO_CONVERTED_LEN);
snprintf(buf, CC26XX_WEB_DEMO_CONVERTED_LEN, "%d", value);
}

list_add(sensor_list, &heard_reading);

process_start(&test_serial_process, NULL);

PROCESS_THREAD(test_serial_process, ev, data)
{
PROCESS_BEGIN();
cc26xx_uart_set_input(serial_line_input_byte);

while(1) {
PROCESS_YIELD();
if(ev == serial_line_event_message && data != NULL) {
if(strcmp(data,"OPEN")==0) {
printf("Open heard");
} else if(strcmp(data,"CLOSE")==0) {
printf("Close heard");
} else {
continue;
}
valor = data;

etimer_set(&et_cen, CLOCK_SECOND * 1 + random_rand() % (CLOCK_SECOND * 1));
PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et_cen));
}

get_heard_reading(NULL);
}
PROCESS_END();
}

2) In cc26xx-web-demo.

define CC26XX_WEB_DEMO_SENSOR_HEARD 15

3) coap-server.h

extern resource_t res_heard;
rest_activate_resource(&res_heard, "Heard/State");

4) res-sensor.c

static void
res_get_handler_heard(void *request, void *response, uint8_t *buffer,
uint16_t preferred_size, int32_t *offset)
{
res_get_handler_all(CC26XX_WEB_DEMO_SENSOR_HEARD, request, response,
buffer, preferred_size, offset);
}

RESOURCE(res_heard, "title=\"State \";rt=\"mV\"",
res_get_handler_heard, NULL, NULL, NULL);

I wrong something?

I suppose your valor should be string type instead of uint16_t .

I suggest you to use value 0 and 1 instead of string first to make sure your code works in COAP interface.

while(1) {
PROCESS_YIELD();
if(ev == serial_line_event_message && data != NULL) {
if(data == 0) {
leds_on(LEDS_RED);
valor = data;
} else if(data == 1) {
leds_off(LEDS_RED);
valor = data;
} else {
continue;

It's ok?

No need to change UART command. Just change valor to 0 and 1.

while(1) {
PROCESS_YIELD();
if(ev == serial_line_event_message && data != NULL) {
if(strcmp(data, "ON")==0) {
data = 0;
} else if(strcmp(data, "OFF")==0) {
data = 1;
} else {
continue;

Yes, the value change of 0 to 1

If you can see 0/1 change on COAP, you can try to change it to use string.

Instead of 0/1, What am I wearing?

I couldn’t understand your question.

I change the uint16_t to char and the int value to char. Instead of 0/1, What I should change?

I write this, but instead of OpenHeard, I see 148


while(1) {
PROCESS_YIELD();
if(ev == serial_line_event_message && data != NULL) {
if(strcmp(data, "ON")==0) {
leds_on(LEDS_RED);
data = ("Open Heard, 10");
} else if(strcmp(data, "OFF")==0) {
leds_off(LEDS_RED);
data = 1;

I cannot do such debug for you. Please check your code thoroughly to see where the problem is.

I did not ask to be debugged, just how to pass the string on the CoAP.

Yikai can you give me some advice on how to insert the string? I do not know how to do