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#include <GxEPD2_BW.h>
#include <Fonts/FreeSansBold9pt7b.h>
#include <Fonts/FreeSans9pt7b.h>
#include <qrcode.h>
#define BLOCK_WIDTH 4
static uint16_t sizes[] = {
17, 32, 53, 78, 106, 134, 154, 192, 230,
};
static void escape_strings(String &text) {
text.replace("\\", "\\\\");
text.replace("\"", "\\\"");
text.replace(";", "\\;");
text.replace(",", "\\,");
text.replace(":", "\\:");
}
static int version_for_len(int length) {
/* assuming ECC_LOW byte qrcodes
sizes taken from table in https://github.com/ricmoo/QRCode/blob/master/README.md */
for (int i = 0; i < sizeof(sizes)/sizeof(uint16_t); i++) {
if (length <= sizes[i])
return i + 1;
}
return -1;
}
int draw_qrcode(GxEPD2_GFX_BASE_CLASS &display, int16_t x, int16_t y, String &text) {
QRCode qrcode;
int version = version_for_len(text.length());
if (version <= 0)
return 0;
uint8_t bytes[qrcode_getBufferSize(version)];
qrcode_initText(&qrcode, bytes, version, ECC_LOW, text.c_str());
/* add quiet zone */
x += 4 * BLOCK_WIDTH;
y += 4 * BLOCK_WIDTH;
for (int row = 0; row < qrcode.size; row++) {
for (int col = 0; col < qrcode.size; col++) {
if (!qrcode_getModule(&qrcode, row, col)) {
continue;
}
display.fillRect(x + BLOCK_WIDTH * row, y + BLOCK_WIDTH * col, BLOCK_WIDTH, BLOCK_WIDTH, GxEPD_BLACK);
}
}
return qrcode.size * BLOCK_WIDTH + 8 * BLOCK_WIDTH;
}
void draw_qrcode_wlan(GxEPD2_GFX_BASE_CLASS &display, int16_t x, int16_t y, const char *ssid, const char *psk) {
String ssid_str = String(ssid);
String psk_str = String(psk);
escape_strings(ssid_str);
escape_strings(psk_str);
/* assuming WPA network; (H)idden attribute is kept at default */
String wifi_str = "WIFI:S:" + ssid_str;
if (psk_str.length() == 0) {
/* open network */
wifi_str += ";;;;";
} else {
wifi_str += ";P:" + psk_str + ";T:WPA;;";
}
int size = draw_qrcode(display, x, y, wifi_str);
/* draw text */
int16_t x2, y2;
uint16_t w, h;
String text_ssid = String("SSID:");
String text_psk = String("PSK:");
display.setFont(&FreeSansBold9pt7b);
display.getTextBounds(text_ssid, 0, 0, &x2, &y2, &w, &h);
display.setCursor(x, y + size + h);
display.print(text_ssid);
display.setFont(&FreeSans9pt7b);
display.setCursor(x + w, y + size + h);
display.print(" " + ssid_str);
if (psk_str.length() > 0) {
display.setFont(&FreeSansBold9pt7b);
display.setCursor(x, y + size + 2 * h + 10);
display.print(text_psk);
display.setFont(&FreeSans9pt7b);
display.setCursor(x + w, y + size + 2 * h + 10);
display.print(" " + psk_str);
}
}
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