TM4C129X - Amazon Web Services(AWS)/Ubidots IoT API

Hello Chuck

Thank you for the reply. Ubidots has a C language based API, 'Ubidots-C', The Github link for the project is github.com/.../ubidots-c.
I tried compiling the same on GCC and ARM compiler (through CCS). The code compiled successfully with GCC, but it failed for ARM compiler(CCS). Wanted to know if there is any way out for this.

Also wanted to know if there are any other cloud services available that could be used with this board(i.e TM4C129X). Basically, we want to grab a value from a sensor and upload it on a cloud server via the board.

Again, any help would be greatly appreciated.

Thanks & Regards
Yash Bhan

I think a TM4C, and other Cortex M4, are representing the minimum of resources and performance for the kind of application(s) you think of.

Having had a brief look at the ubidots C-API, basic HTTP is surely doable, choosing a proper TCP/IP stack. IMHO forget about HTTPS.

I tried compiling the same on GCC and ARM compiler (through CCS). The code compiled successfully with GCC, but it failed for ARM compiler(CCS). Wanted to know if there is any way out for this.

AFAIK, the CCS default toolchain is also GCC based (needing more than single-vendor support, I don't use CCS). It is probably helpful if you can post a log of the build errors here.

While compiling the code on CCS, i get the following error:

**** Build of configuration Debug for project ubidots ****

"C:\\ti\\ccsv5\\utils\\bin\\gmake" -k all 
'Building file: ../ubidots.c'
'Invoking: ARM Compiler'
"C:/ti/ccsv5/tools/compiler/arm_5.0.4/bin/armcl" -mv7M4 --code_state=16 --float_support=FPv4SPD16 --abi=eabi -me -g --include_path="C:/ti/ccsv5/tools/compiler/arm_5.0.4/include" --include_path="F:/CCS_workspace/include" --diag_warning=225 --display_error_number --diag_wrap=off --preproc_with_compile --preproc_dependency="ubidots.pp"  "../ubidots.c"
"F:\CCS_workspace\include\curl\curlbuild.h", line 122: fatal error #5: could not open source file "windows.h"
1 fatal error detected in the compilation of "../ubidots.c".
Compilation terminated.
gmake: *** [ubidots.obj] Error 1

>> Compilation failure
'Building file: ../ubirequest.c'
'Invoking: ARM Compiler'
"C:/ti/ccsv5/tools/compiler/arm_5.0.4/bin/armcl" -mv7M4 --code_state=16 --float_support=FPv4SPD16 --abi=eabi -me -g --include_path="C:/ti/ccsv5/tools/compiler/arm_5.0.4/include" --include_path="F:/CCS_workspace/include" --diag_warning=225 --display_error_number --diag_wrap=off --preproc_with_compile --preproc_dependency="ubirequest.pp"  "../ubirequest.c"
"F:\CCS_workspace\include\curl\curlbuild.h", line 122: fatal error #5: could not open source file "windows.h"

1 fatal error detected in the compilation of "../ubirequest.c".
>> Compilation failure
Compilation terminated.
gmake: *** [ubirequest.obj] Error 1
gmake: Target `all' not remade because of errors.

**** Build Finished ****

Im using the sample code available at the ubidots-c github repo.

Code:

/*
 * Ubidots C client.
 *
 * Copyright (c) 2013 Ubidots.
 */

#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <curl/curl.h>
#include <jansson.h>
#include "ubidots.h"
#include "ubirequest.c"

/**
 * Save a value to Ubidots.
 * @arg client       Pointer to UbidotsClient
 * @arg variable_id  The ID of the variable to save to
 * @arg value        The value to save
 * @arg timestamp    Timestamp (millesconds since epoch). Pass TIMESTAMP_NOW
 *                   to have the timestamp automatically calculated.
 * @return Zero upon success, Non-zero upon error.
 */
int ubidots_save_value(UbidotsClient *client, char *variable_id, double value, long long timestamp) {
  char url[80];
  char json_data[80];

  if (timestamp == TIMESTAMP_NOW)
    timestamp = (long long)time(NULL) * 1000;

  sprintf(url, "%s/variables/%s/values", client->base_url, variable_id);
  sprintf(json_data, "{\"value\": %g, \"timestamp\": %lld}", value, timestamp);

  return ubi_request("POST", url, client->token, json_data, NULL);
}


/**
 * Initialize a Ubidots session. This is most likely the first Ubidots
 * library function you will call.
 * @arg api_key  Your API key for the Ubidots API.
 * @return Upon success, a pointer to a UbidotsClient. Upon error, NULL.
 */
UbidotsClient* ubidots_init(char *api_key) {
  return ubidots_init_with_base_url(api_key, DEFAULT_BASE_URL);
}


UbidotsClient* ubidots_init_with_base_url(char *api_key, char *base_url) {
  // Perform an API request to generate a new token for the given API key.
  char url[80];
  char token_hack[80];
  int rc;
  json_t *j_root, *j_token;
  
  sprintf(url, "%s/auth/token", base_url);
  sprintf(token_hack, "/%s", api_key);
  
  rc = ubi_request("POST", url, token_hack, "", &j_root);
  
  if (rc)
    return NULL;
  
  j_token = json_object_get(j_root, "token");

  // Allocate and set fields of struct
  UbidotsClient *client = malloc(sizeof(UbidotsClient));  

  strncpy(client->base_url, base_url, STRLEN_BASE_URL);
  strncpy(client->api_key, api_key, STRLEN_API_KEY);
  strncpy(client->token, json_string_value(j_token), STRLEN_TOKEN);

  json_decref(j_root);

  return client;
}


/**
 * End a ubidots session. After calling this function with UbidotsClient* client,
 * no more functions may be called with it.
 */
void ubidots_cleanup(UbidotsClient *client) {
  free(client);
}


int main() {
	char API_KEY[] = "4eab4440fe98e0eb5ab432691f80fbc3434b76f4";
	char VARIABLE_ID[] = "57d7ba927625425b779a7340";
     UbidotsClient *client = ubidots_init(API_KEY);

     //while ( keepGoing() ) {
       double value = 10; //getValue();
       ubidots_save_value(client, VARIABLE_ID, value, TIMESTAMP_NOW);
     //}
  
     ubidots_cleanup(client);

     return 0;
   }

I just want to send a value(10) to ubidots cloud server. while compiling with GCC, im not getting any error and the binary is getting generated succesfully, but when compiling with CCS, im getting errors as shown in the build error log above.

Is there any sample program that demonstrates how to send data to Cloud (AWS /Ubidots) using REST api via the board.

Thanks & Regards

Yash Bhan 

I'm not much in IoT projects, for several reasons.

"F:\CCS_workspace\include\curl\curlbuild.h", line 122: fatal error #5: could not open source file "windows.h"

Well, there is no "windows.h" here for the TM4C, for obvious reasons.

I think you need to get / make a "matching" build of the curl library, not one based on the Windows OS (or Linux). Or perhaps change the curl sources "in place".

I'm afraid you won't find too much of this competence here in a "hardcore bare-metal" forum ...

Hello Chuck

Thank you for the reply. I will try setting up the board with the exosite cloud server. However, i don't have the default application("qs_iot") in the tivaware software which was bundled with the board, the said app is bundled with the board with model no: EK-TM4C1294XL, whereas, i have model DK-TM4C129X. Both the boards have the same MCU. Wanted to know if i could flash the default cloud application("qs_iot"), on this board(DK-TM4C129X)?

Thanks & Regards
Yash Bhan