Hardware abstraction
Posted: Sat Nov 21, 2015 1:00 pmI've begun to port HWA to ESP8266. HWA is a set of C macro definitions that provide an object-oriented description of the hardware of a device, ad-hoc polymorphism and instructions that accept a variable length of arguments.
I am only at the beginning but there is an example of what it looks like in action (I need to be able to put TXD low for some time while another micro-controller leaves the reset state):
Some documentation and a bunch of gradually elaborate examples for Atmel AVRs here. The source is hosted on Github (the ESP8266 branch is not pushed yet).
I am only at the beginning but there is an example of what it looks like in action (I need to be able to put TXD low for some time while another micro-controller leaves the reset state):
Code: Select all
#include <hwa/modules/esp-wroom-02.h>
#define LED hw_pin_gpio5
#define IROM __attribute__((section (".irom.text")))
#define IRAM
/* Function called every 10 ms
* * toggle the LED on/off every 200 ms
* * when the LED is turned on, turn TXD low for 100 ms
* * when the LED if turned off, send "ON\n" on TXD
*/
void IROM every10ms ( )
{
static uint8_t count ;
static uint8_t txdlow ;
if ( txdlow ) {
txdlow-- ;
if ( txdlow == 0 )
/*
* TXD has been set low for 100 ms. Release it now: connect pin GPIO1 to
* the TXD signal
*/
hw_config( hw_pin_gpio1, function, hw_uart0_txd );
}
count++ ;
if ( count < 20 )
return ;
/* The following is done once every 200 ms
*/
count = 0 ;
if ( hw_read( LED ) == 0 ) {
/*
* Turn LED on
*/
hw_write( LED, 1 );
/*
* Turn TXD low for 100 ms: connect pin GPIO1 to the GPIO1 signal
*/
txdlow = 10 ;
hw_config( hw_pin_gpio1, function, gpio );
}
else {
/*
* Turn LED off
*/
hw_write( LED, 0 );
/*
* Send message
*/
os_printf("ON\n");
}
}
void IROM user_init()
{
hw_config( LED,
function, gpio, // Optionnal
direction, output_when_awake
);
/* Pin GPIO1 is also used as pin TXD of hw_uart0
* We want a low level on that pin when used as a GPIO
*/
hw_config( hw_pin_gpio1,
function, gpio, // Optionnal
direction, output );
hw_write( hw_pin_gpio1, 0 );
/* Configure the UART
* Note: the OS has already configured the RXD and TXD pins
*/
hw_config( hw_uart0,
baudrate, 9600,
databits, 8,
parity, none,
stopbits, 1,
/* pin_txd, hw_pin_gpio1, */
/* pin_rxd, hw_pin_gpio3, */
);
os_printf("Hello World!\n");
/* Trigger a function call every 10 ms (about)
*/
static os_timer_t timer ;
os_timer_disarm( &timer );
os_timer_setfn( &timer, (os_timer_func_t *)every10ms, NULL );
os_timer_arm( &timer, 10, 1 );
}
Some documentation and a bunch of gradually elaborate examples for Atmel AVRs here. The source is hosted on Github (the ESP8266 branch is not pushed yet).