Review schematic nRF52833

[lupinn]

HI,

I am building an IoT product using NRF58233 ICs.
In which I use 3 PWM channels and 3 ADC channels.
You can review the principle I attached to make sure nothing went wrong. Thanks

[mathiaso]

Hi.

I'll have a look at the schematic and get back to you.

Best regards,
Mathias

[lupinn]

thanks

[mathiaso]

What is your crystal's load capacitance? The capacitors connected to it should have the value Ccap = 2*CL - 4 pF, where CL is the crystal's load capacitance.

Could you please upload your schematic as a vectorised pdf, rather than as a screenshot?

[lupinn]

Hi, There are a few things I'm not clear about:
1. Can P0.00/XL1 pin be used as ADC (analog input)
2. Configure the power supplynRF52833.pdf

[mathiaso]

Hi.

lupinn said:

1. Can P0.00/XL1 pin be used as ADC (analog input)

No, the pin used for the positive input to the ADC is chosen in the CH[n].PSELP register and the pin used for the negative input to the ADC is chosen in the CH[n].PSELN register. As you can see there, the inputs named AINx must be used as inputs for the ADC.

Some comments about your schematic follow.

• The 2.2 nH series inductor found in the reference schematic is also a part of the radio's matching network. The antenna is likely to have its own matching network. Do you have the antenna's datasheet?
    
• The decoupling cap connected to where VDD and VDDH are shorted should have a value of 4.7 µF, rather than 1 µF.
  

Best regards,
Mathias

[lupinn]

thank you so much. One more question, pin P0.01/XL2 can be used PWM?

[mathiaso]

The short answer is yes.

As seen in the PSEL.OUT[n] register, every GPIO pin is possible to use with PWM. Some pins are however only recommended for use with "Standard drive, low frequency I/O only", as described in the pin assignments, which could make them less suited for use with PWM. But this is not the case for the P0.01/XL2 pin.