PIC24 selection advice

[joesaliba]

Been a while since posting something, but very, very busy.

This is the first time to try using a PIC24, so I tried looking up on Microchip MAPS to find a suitable 14-pin to 18-pin PIC24.

The most requirement I am looking for is 2x USART with one of them the capability to invert both Tx and Rx signal, and an IOC on 1 pin.

Internal oscillator of 20MHz or more will be perfect.

Thank you
Kind regards

Joe

[tumbleweed]

There aren't too many 16-bit parts in the smaller packages to pick from.
You might have a better choice if you can switch to a 20-pin package...

[joesaliba]

20 pin will do. I have no pcb dome yet.

[Gamboa]

Joesaliba,

Look at this family PIC24FJ256GA705 of processors, they are cheap and powerful. You have them from 28 pins.

Regards,
Gamboa

[SCV]

Critically, look to what's available from your normal supplier and select from there.

[tumbleweed]

For a 20 pin parts with 2 uarts you could look at the pic24FxxKA102 family.

[trastikata]

Critically, look to what's available from your normal supplier and select from there.

And to add to this, check if the device is supported by Positron16.

[joesaliba]

Sorry for the late reply.

Thank you so much for information

For a 20 pin parts with 2 uarts you could look at the pic24FxxKA102 family.

.

Cannot find on datasheet if I can invert a USART Tx/Rx.

[trastikata]

Cannot find on datasheet if I can invert a USART Tx/Rx.

Helo Joe,

Not sure what do you mean by inverting Tx/Rx? Swapping the TX/RX pins or invert their idle state?

[joesaliba]

Invert their idle state, polarity inverse I read in one data sheet.

[trastikata]

Invert their idle state, polarity inverse I read in one data sheet.

https://ww1.microchip.com/downloads/en/DeviceDoc/en026583.pdf

bit4 RXINV: Receive Polarity Inversion bit in UxMODE
bit14 UTXINV: Transmit Polarity Inversion bit in UxSTA

[John Lawton]

You beat me to it!

I'd like to know how you found DS39708 on the Microchip website, I couldn't

John

[trastikata]

I'd like to know how you found DS39708 on the Microchip website, I couldn't

Google knows everything  . It seems many links in MC datasheets are outdated, thus I simply google the document number and it is usually among the first 3 results.

[John Lawton]

Ah, thanks. I don't use Google search because of their censorship on certain topics, but I see it has its uses. The search on the Microchip site is awful for finding these docs.

[trastikata]

@joesaliba

Peripherals in the same 16b family usually share the same registers and functionality, so instead of repeating the same information in every datasheet, MC decided to make a common reference datasheet for each peripheral module and refer to it in the device datasheet.

Thus if you look for example in the PIC24FJ256GA705 datasheet, section UNIVERSAL ASYNCHRONOUS RECEIVER TRANSMITTER (UART), you will see this note:

Note: This data sheet summarizes the features of
this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information, refer to
the "dsPIC33/PIC24 Family Reference
Manual", "UART" (DS39708), which is
available from the Microchip web site
(www.microchip.com). The information
in this data sheet supersedes the
information in the FRM.

As I said in my previous post to John, links usually don't work, so just google the document number.

[trastikata]

Ah, thanks. I don't use Google search because of their censorship on certain topics, but I see it has its uses. The search on the Microchip site is awful for finding these docs.

I gave up on MC site for any datasheets or other reference too, indeed it's terrible and really hard to find anything.

[John Lawton]

Indeed.

I found this list of site links on a Microchip forum post which some might find useful:

https://www.microchip.com/forums/m391727.aspx#391728

John

[joesaliba]

Sorry for the late reply.

Thank you so much for the help. I will read through the datasheets and reference manual.

Regards

Joe