Difference between revisions of "ARM Embedded Tutorial - Raspberry Pi Pico saying Hello via UART"

From Lazarus wiki
Jump to navigationJump to search
m (→‎See also: New section)
 
(3 intermediate revisions by one other user not shown)
Line 1: Line 1:
 
{{ARM Embedded Tutorial - Raspberry Pi Pico saying Hello via UART}}
 
{{ARM Embedded Tutorial - Raspberry Pi Pico saying Hello via UART}}
  
−
The next peripheral on the tutorial list is the UART.
+
== Introduction ==
  
 +
UART Interfaces are often used for debugging output, the pico is no exception to this rule.
 +
 +
This application is best tested with picoprobe, when you connect it to your development board as described in the Getting Started Guide chapter then the GPIO pins 0 and 1 are connected to the debug probe which makes them visible as a serial interface on your computer.
 +
 +
Here's again our debugging setup on a breadboard, the picoprobe is on the right, the pico that will run our code is on the left:
 +
 +
[[File:picoPicoDebug_Steckplatine.png|800px]]
  
 
<syntaxhighlight lang=pascal>
 
<syntaxhighlight lang=pascal>
Line 8: Line 15:
 
{$MODE OBJFPC}
 
{$MODE OBJFPC}
 
{$H+}
 
{$H+}
 +
{$MEMORY 10000,10000}
  
 
uses
 
uses
Line 31: Line 39:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
One notable change is that you may have seen that we do not provide <tt>__aeabi_uidiv</tt> anymore, instead we link to <tt>libgcc.a</tt> and get (hopefully) best possible performance for the unsigned integer division.
 
  
−
This application is best tested with picoprobe, when you connect it to your development board as described in the Getting Started Guide chapter then the GPIO pins 0 and 1 are connected to the debug probe which makes them visible as a serial interface on your computer.
 
  
 
Connect your terminal program to the UART port and enjoy the message from your Pico.
 
Connect your terminal program to the UART port and enjoy the message from your Pico.
 +
In this example we are using ansistrings, so the $MEMORY setting is important as we will use dynamically allocated AnsiStrings.
 +
To visually get confirmation that the app is running we additionally blink the LED on each turn of the main loop.
 +
 +
== See also ==
  
−
[[ARM Embedded Tutorial - FPC and the Raspberry Pi Pico|Back to main Pico Page]]
+
* [[ARM Embedded Tutorial - FPC and the Raspberry Pi Pico|ARM Embedded Raspberry Pi Pico Tutorials]]

Latest revision as of 02:53, 30 December 2021

│ English (en) │

Introduction

UART Interfaces are often used for debugging output, the pico is no exception to this rule.

This application is best tested with picoprobe, when you connect it to your development board as described in the Getting Started Guide chapter then the GPIO pins 0 and 1 are connected to the debug probe which makes them visible as a serial interface on your computer.

Here's again our debugging setup on a breadboard, the picoprobe is on the right, the pico that will run our code is on the left:

picoPicoDebug Steckplatine.png 

program uart;
{$MODE OBJFPC}
{$H+}
{$MEMORY 10000,10000}

uses
  pico_uart_c,
  pico_gpio_c,
  pico_timer_c;
const
  BAUD_RATE=115200;
begin
  gpio_init(TPicoPin.LED);
  gpio_set_dir(TPicoPin.LED,TGPIODirection.GPIO_OUT);
  uart_init(uart0, BAUD_RATE);
  gpio_set_function(TPicoPin.GP0_UART0_TX, TGPIOFunction.GPIO_FUNC_UART);
  gpio_set_function(TPicoPin.GP1_UART0_RX, TGPIOFunction.GPIO_FUNC_UART);
  repeat
    gpio_put(TPicoPin.LED,true);
    uart_puts(uart0, 'Hello, UART!'+#13+#10);
    busy_wait_us_32(500000);
    gpio_put(TPicoPin.LED,false);
    busy_wait_us_32(500000);
  until 1=0;
end.


Connect your terminal program to the UART port and enjoy the message from your Pico. In this example we are using ansistrings, so the $MEMORY setting is important as we will use dynamically allocated AnsiStrings. To visually get confirmation that the app is running we additionally blink the LED on each turn of the main loop.

See also

Retrieved from "http://wiki.freepascal.org/index.php?title=ARM_Embedded_Tutorial_-_Raspberry_Pi_Pico_saying_Hello_via_UART&oldid=148831"