Error in sending ADC reading to MQTT broker

[yeo]

Dear Nordic community,

I am currently trying to send ADC sensor reading to MQTT broker(hivemq). I have successfully sent some data to the mqtt broker. However, the reading fo the data that I am sending is 0, which is not the adc sensor reading that it should be (meaning that the data_value is not updated and remains in its initial value). Below is my attached file, can anyone give me some suggestions?

 mqtt_simple_sensor (3).zip

[Håkon Alseth]

Hi,

 

I tested your program, and when connecting AIN1 to VDD (3.0V), I get this output:

ADC raw value(s): 851

calculated value: 0.6V/(1/6) * 851/2^10 = 2.992 V

 

Please note that AIN1 is P0.14, and if you're enabling modem traces, this corresponds to uart1 RTS pin.

 

Your timer "my_timer" is being overwritten, so that my_work_handler isn't called.

Try issuing your workqueue from the timer (ie. adc_sample_event()) instead, and do not re-init the k_timer instance.

 

Kind regards,

Håkon

[yeo]

Hi, thanks for the help. However, I am still having trouble trying to update "data_value". Could you please help me to modify the code?

[yeo]

mqtt_simple_sensor (4).zip

Hi, I tried to modify my code and arrange the sequence of the timer. Now I am not able to print and publish anything. 

[yeo]

I have issue workqueue from the timer in adc_sample_evemnt() and modified the code. However, now I am not able to print and publish anything. Please refer to the latest code below. 

  mqtt_simple_sensor (5).zip

Best regards,

Yeo

[Håkon Alseth]

Hi,

 

In your latest .zip file, the adc event handler is defined multiple times, and the timer itself is not started. 

I would recommend that you start from scratch, by taking mqtt_simple, and add one component until you get that working, and then add your next component.

 

Kind regards,

Håkon