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SmartRF05 EB with CC2541 EM using ADC

Jose Flavio Goulart Mendes
Prodigy 20 points
Other Parts Discussed in Thread: CC2541, LM35, CC2530

Hello,

I'm trying to make an prototype of an thermometer. I'd like to know if it's possible to connect the sensor to SmartRF05 GPIO and use it in CC2541 EM ADC pin. Is it possible?

Then i'll go to the codes and get the converted V of ADC and display it on the display. After that i'll use the BLE to transfer data.

Thank you.

  • 0
    TI__Guru 56590 points

    Hello Jose, 

    What kind of sensor do you mean?

    If you download the CC2541/43/44/45 Peripherals Software Examples you can find the pin out for the CC2541EM mounted on the SmartRF05EB at the end of the following document: cc2541_43_44_45_Peripherals_Software_Examples_Overview.pdf 

  • 0 in reply to Eirik V
    Prodigy 20 points

    Hello Eirik V,

    Thanks for replying. The sensor I want to use is a NTC type, can be the LM35 or any sensor that I can measure human temperature, or water liquid temperature.

    So, I know it is a starting question but I don't know how to connect the sensor to send the Voltage to ADC pins on the cc2541. I think the correct is to connect the sensor to SmartRF05 gpio pins and with programming I'll send the V to ADC, is that correct? I can get any IO pin or have to be specified?

    http://www.ti.com/lit/ds/symlink/lm35.pdf

    Thanks,

    Jose Flavio

  • 0 in reply to Jose Flavio Goulart Mendes
    TI__Guru 56590 points

    Hello Jose,

    To connect to the ADC you will have to use on of the port 0 pins (P0.X) as this is the only place the ADC channels are routed (refer to Table 7-1. "Peripheral I/O Pin Mapping" in the CC253x/4x User Guide ). The Sensor should have a common ground with the CC2541 Module.

    But the problem here is that the temperature sensor needs a higher supply voltage than the max rating for the CC2541 (3.6 V). So you need a DCDC converter to step up the voltage above 4 Volts. I can see that the usual operating range of the sensor signal should be within the limits for the CC2541, but you have to make sure that the voltage from the sensor pin that is connected to the CC2541 GPIO stays within the limits ( VDD + 0.3 ≤ 3.9 V ) or else you can damage the chip and your measurements will be wrong.

    . 

  • 0 in reply to Eirik V
    Intellectual 545 points

    Hai Jose,

    is there any example Peripheral codes available for CC2530..???

    if there please suggest me link.