#if 1
#include <avr/pgmspace.h>
-char base64_alphabet[64] PROGMEM = {
+const char base64_alphabet[64] PROGMEM = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
#endif
-void base64enc(char* dest, void* src, uint16_t length){
+void base64enc(char* dest,const void* src, uint16_t length){
uint16_t i,j;
uint8_t a[4];
for(i=0; i<length/3; ++i){