1 files changed, 105 insertions, 0 deletions
diff --git a/test/sdcc18/usart_test.c b/test/sdcc18/usart_test.c
new file mode 100644
index 0000000..1b611d9
--- /dev/null
+++ b/test/sdcc18/usart_test.c
@@ -0,0 +1,105 @@
+// read and write eeprom of PIC18F2550 (and 18F2455, 18F4455, 18F4550)
+// EEPROM size is 256 bytes
+// (c) Raphael Wimmer. Licensed under GNU GPL v2 or higher
+#include <pic18f452.h>
+//#include <pic18fregs.h>
+#include <stdio.h>
+#include <usart.h>
+#include <adc.h>
+
+code char at __CONFIG1H config1h = 0xFF & _OSC_XT_1H & _OSCS_OFF_1H;
+code char at __CONFIG2L config2l = 0xFF & _PUT_ON_2L & _BODEN_OFF_2L & _BODENV_2_7V_2L;
+code char at __CONFIG2H config2h = 0xFF & _WDT_OFF_2H;
+code char at __CONFIG3H config3h = 0xFF & _CCP2MUX_RC1_3H;
+code char at __CONFIG4L config4l = 0xFF & _LVP_OFF_4L & _BACKBUG_ON_4L & _STVR_OFF_4L;
+code char at __CONFIG5L config5l = 0xFF & _CP_0_OFF_5L & _CP_1_OFF_5L;
+code char at __CONFIG5H config5h = 0xFF & _CPD_OFF_5H & _CPB_OFF_5H;
+code char at __CONFIG6L config6l = 0xFF & _WRT_0_OFF_6L & _WRT_1_OFF_6L;
+code char at __CONFIG6H config6h = 0xFF & _WRTD_OFF_6H & _WRTB_OFF_6H & _WRTC_OFF_6H;
+code char at __CONFIG7L config7l = 0xFF & _EBTR_0_OFF_7L & _EBTR_1_OFF_7L;
+code char at __CONFIG7H config7h = 0xFF & _EBTRB_OFF_7H;
+
+#pragma stack 0x300 0xff // set 64 byte stack at 0x300, needed by sdcc
+
+static void isr(void) interrupt 1 {
+/*
+n Interrupt     Vector  Interrupt Vector Address
+0 RESET         vector  0x000000
+1 HIGH priority interrupts 0x000008
+2 LOW priority interrupts 0x000018
+*/
+}
+
+void ee_write_byte(unsigned char address, unsigned char *_data){
+
+    EEDATA = *_data;
+    EEADR = address;
+    // start write sequence as described in datasheet, page 91
+    EECON1bits.EEPGD = 0;
+    EECON1bits.CFGS = 0;
+    EECON1bits.WREN = 1; // enable writes to data EEPROM
+    INTCONbits.GIE = 0;  // disable interrupts
+    EECON2 = 0x55;
+    EECON2 = 0x0AA;
+    EECON1bits.WR = 1;   // start writing
+    while(EECON1bits.WR){
+        _asm nop _endasm;}
+    if(EECON1bits.WRERR){
+       // printf("ERROR: writing to EEPROM failed!\n");
+    }
+    EECON1bits.WREN = 0;
+    INTCONbits.GIE = 1;  // enable interrupts
+}
+
+void adc_start() {
+
+        adc_open(ADC_CHN_1, ADC_FOSC_4, ADC_CFG_5A_0R, ADC_FRM_RJUST);
+        while (adc_busy()) ;
+        adc_read();
+//unsigned char channel, unsigned char fosc, unsigned char pcfg, unsigned char config
+
+}
+
+void ee_read_byte(unsigned char address, unsigned char *_data){
+    EEADR = address;
+    EECON1bits.CFGS = 0;
+    EECON1bits.EEPGD = 0;
+    EECON1bits.RD = 1;
+    *_data = EEDATA;
+}
+
+void initUsart()
+{
+    usart_open(    // Use USART library to initialise the hardware
+            USART_TX_INT_OFF
+            & USART_RX_INT_OFF
+            & USART_BRGH_HIGH
+            & USART_ASYNCH_MODE
+            & USART_EIGHT_BIT,
+            10                      // '10' = 115200 Baud with 20 MHz oscillator and BRGH=1
+            );
+    stdout = STREAM_USART;
+}
+
+
+
+// very simple example. use on an erased eeprom
+
+void main(){
+
+    char save_me = 'c';
+    char from_eeprom;
+       adc_start();
+    initUsart();
+
+    printf("E");
+    ee_read_byte(0x00, &from_eeprom);
+    printf("%c", from_eeprom);
+
+    ee_write_byte(0x00, &save_me);
+    printf("%c", save_me);
+
+    ee_read_byte(0x00, &from_eeprom);
+    printf("%c", from_eeprom);
+while (1){}
+}