1 files changed, 147 insertions, 0 deletions
diff --git a/assets/js/xymini.js b/assets/js/xymini.js
new file mode 100644
index 0000000..a1fd1ca
--- /dev/null
+++ b/assets/js/xymini.js
@@ -0,0 +1,147 @@
+/* XYMini Sender - Minimal implementation of file transfer through serial
+ * Copyright (C) Ernesto Castellotti <mail@ernestocastellotti.it>
+ * SPDX-License-Identifier: MPL-2.0-no-copyleft-exception
+ *
+ * Warning: This does not comply with XMODEM and YMODEM standards
+*/
+
+const STX = 0x02;
+const ACK = 0x06;
+const NAK = 0x15;
+const EOF = 0x04;
+const XYMINI_1K_MAGIC = 0x43;
+const PAYLOAD_LEN = 1024;
+const BLOCK_LEN = PAYLOAD_LEN + 5;
+const CRC_POLY = 0x1021;
+
+function uint16 (n) {
+  return n & 0xFFFF;
+}
+
+function updateCrc(crcIn, incr) {
+    const xor = uint16(crcIn >> 15);
+    let result = uint16(crcIn << 1);
+
+    if (incr) {
+        result = uint16(result + 1);
+    }
+
+    if (xor) {
+        result = uint16(result ^= CRC_POLY);
+    }
+
+    return result;
+}
+
+function crc16(data) {
+    let crc;
+
+    for (let i = 0; i < data.length; i++) {
+        for (let j = 0x80; j; j >>= 1) {
+            crc = updateCrc(crc, data[i] & j);
+        }
+    }
+
+    for (let n = 0; n < 16; n++) {
+        crc = updateCrc(crc, 0);
+    }
+
+    return crc;
+}
+
+async function detectXYMini(reader) {
+    const textDecoder = new TextDecoder();
+
+    while (true) {
+        const { value, done } = await reader.read();
+
+        if (value[0] == XYMINI_1K_MAGIC) {
+            console.log("XYMini: detected");
+            break;
+        }
+    }
+}
+
+function generateXYMiniBlock(blockId, payload) {
+    let buf = new Uint8Array(BLOCK_LEN);
+    let i = 0;
+
+    buf[i++] = STX;
+    buf[i++] = blockId;
+    buf[i++] = 0xFF - blockId;
+
+    if (payload.length > PAYLOAD_LEN) {
+        throw new Error("Payload too large to be transmitted in one block");
+    }
+
+    for (let j = 0; j < payload.length; j++) {
+        buf[i++] = payload[j];
+    }
+
+    while (i < BLOCK_LEN - 2) {
+        buf[i++] = 0xFF;
+    }
+
+    let crcBuf = buf.slice(3, PAYLOAD_LEN + 3)
+    let crc = crc16(crcBuf);
+
+    buf[i++] = (crc >> 8) & 0xFF;
+    buf[i++] = crc & 0xFF;
+
+    return buf;
+}
+
+async function sendXYMini(portReader, portWriter, data, baudRate = 115200, progressCallback) {
+    let blockId = 1;
+    let size = data.length;
+    let i = 0;
+    let nakN = 0;
+    let wrongCharN = 0;
+
+    await detectXYMini(portReader);
+
+    while(true) {
+        const payloadSize = Math.min(PAYLOAD_LEN, size);
+
+        if (size) {
+            const payload = data.slice(i, payloadSize + i);
+
+            const block = generateXYMiniBlock(blockId, payload);
+            await portWriter.write(block);
+        } else {
+            portWriter.write(new Uint8Array([EOF]));
+        }
+
+        const { value, done } = await portReader.read();
+
+        if (value[0] == ACK) {
+            if (!size) {
+                console.log("XYMini: End of transmission");
+
+                return;
+            }
+
+            blockId++;
+            size -= payloadSize;
+            i += payloadSize;
+            nakN = 0;
+            wrongCharN = 0;
+            progressCallback(data.length - size);
+        } else if (value[0] == NAK) {
+            if (nakN >= 10) {
+                throw new Error("Received 10 NAK, receiver is rejecting file transmission");
+            }
+
+            console.log("XYMini: NAK");
+            nakN++;
+        } else {
+            if (wrongCharN >= 30) {
+                throw new Error("Received 30 wrong characters, the receiver is rejecting the transmission or the connection is too noisy");
+            }
+
+            console.log("XYMini: wrong character");
+            console.log(value);
+            wrongCharN++;
+        }
+    }
+}