Problem with fredorch f21s

memnongr · December 10, 2025, 2:32pm

when i load funscripts it actually feels like ignoring some commands. also making huge steps as if it tries to make the movement with max intensity. lets say it is commanded to do a 7 cm stroke in 1 sec it tries to do it wit full speed as soon as possble in 0.2 secs any idea how to modify the scripts or what to do? i tried modifying giving more commands and splitting the movement in more steps but it eds up in a machinegun movemen hahaha like small fast jumps. Solutions?

er0s1 · December 10, 2025, 2:55pm

giphy

I have no advice for you sorry, you just made me laugh

memnongr · December 10, 2025, 3:37pm

From the info i gathered so far. it has something to do with the fact that f21s doesn’t support free mode, or something. I also found the protocol of the machine here:
Document Fredorch F21S/T8 protocol

github.com/buttplugio/stpihkal

Document Fredorch F21S/T8 protocol

opened 02:07PM - 19 Jul 21 UTC

blackspherefollower

BLE Name: YXlinksSPP Service UUID: 0000ffb0-0000-1000-8000-00805f9b34fb Tx Cha…racteristic UUID: 0000ffb1-0000-1000-8000-00805f9b34fb Rx Characteristic UUID: 0000ffb2-0000-1000-8000-00805f9b34fb Device is a positional belt driven linear actuator: * 9 oscillation patterns (speed and range controllable) * Programmable sequences * On-demand movements Pattern mode: * Initialisation: `01 06 00 64 00 00 CRC16` * On: `01 06 00 65 00 01 CRC16` * Off: `01 06 00 65 00 00 CRC16` * Speed up: `01 06 00 66 00 02 CRC16` * Speed down: `01 06 00 66 00 01 CRC16` * Range up: `01 06 00 67 00 02 CRC16` * Range down: `01 06 00 67 00 01 CRC16` * Pattern select `01 06 00 68 00 0X CRC16` (X 1-9 pattern number) Free mode: * Initialisation: `01 06 00 64 00 02 CRC16` * Move: `01 06 00 A7 XX YY CRC16` (XX YY position 16-bit hex value which seems to max out at 225 but app sends 0-100, like 0x00 0x99 for 99, in decimal, like 0x00 0x99 for 99, which I bet this is a bug in their app) Program mode: * Initialisation: `01 06 00 64 00 01 CRC16` * Play: `01 06 00 69 00 01 CRC16` * Program: `01 06 00 69 00 00 CRC16` * Loop: `01 06 00 6a 00 01 CRC16`/ `01 06 00 6a 00 00 CRC16` * Set phase: At this point some of the protocol became clearer (or so I though, since the data doesn't match my assertions): * All messages start 0x01 * The second byte is the message length, until now always 6 * The 3rd/4th bytes are the command or storage location (programs are stored on 6B+3N) * `01 10 00 6B 00 05 0a [speed out] [speed in] [position in] [position out] [repeat count] CRC16` Turns out that if you initialise the program with: * `01 06 00 64 00 01 CRC16`: Set to program mode * `01 06 00 69 00 00 CRC16`: Set to record state * `01 10 00 6b 00 05 0a 00 05 00 05 00 00 00 00 00 01 CRC16`: Set the first oscillation pattern to move to 0 and stay * `01 06 00 69 00 01 CRC16`: Run the program * `01 06 00 6a 00 01 CRC16`: Enable loop You can then send follow-up position/speeds by just sending: * `01 10 00 6b 00 05 0a 00 05 00 05 00 90 00 90 00 01 CRC16`: Move to 144 at speed 5 ```javascript _auchCRCHi = [0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64, 0, 193, 129, 64, 1, 192, 128, 65, 0, 193, 129, 64, 1, 192, 128, 65, 1, 192, 128, 65, 0, 193, 129, 64]; _auchCRCLo = [0, 192, 193, 1, 195, 3, 2, 194, 198, 6, 7, 199, 5, 197, 196, 4, 204, 12, 13, 205, 15, 207, 206, 14, 10, 202, 203, 11, 201, 9, 8, 200, 216, 24, 25, 217, 27, 219, 218, 26, 30, 222, 223, 31, 221, 29, 28, 220, 20, 212, 213, 21, 215, 23, 22, 214, 210, 18, 19, 211, 17, 209, 208, 16, 240, 48, 49, 241, 51, 243, 242, 50, 54, 246, 247, 55, 245, 53, 52, 244, 60, 252, 253, 61, 255, 63, 62, 254, 250, 58, 59, 251, 57, 249, 248, 56, 40, 232, 233, 41, 235, 43, 42, 234, 238, 46, 47, 239, 45, 237, 236, 44, 228, 36, 37, 229, 39, 231, 230, 38, 34, 226, 227, 35, 225, 33, 32, 224, 160, 96, 97, 161, 99, 163, 162, 98, 102, 166, 167, 103, 165, 101, 100, 164, 108, 172, 173, 109, 175, 111, 110, 174, 170, 106, 107, 171, 105, 169, 168, 104, 120, 184, 185, 121, 187, 123, 122, 186, 190, 126, 127, 191, 125, 189, 188, 124, 180, 116, 117, 181, 119, 183, 182, 118, 114, 178, 179, 115, 177, 113, 112, 176, 80, 144, 145, 81, 147, 83, 82, 146, 150, 86, 87, 151, 85, 149, 148, 84, 156, 92, 93, 157, 95, 159, 158, 94, 90, 154, 155, 91, 153, 89, 88, 152, 136, 72, 73, 137, 75, 139, 138, 74, 78, 142, 143, 79, 141, 77, 76, 140, 68, 132, 133, 69, 135, 71, 70, 134, 130, 66, 67, 131, 65, 129, 128, 64]; function padLeft(e, t, n) { void 0 == n && (n = "0"); for (var o = 0, i = t - e.length; o < i; o++) { e = n + e; } return e; } function CRC16(t) { for (var n = 255, o = 255, i = 0; i < t.length; i++) { var a = n ^ t[i]; n = o ^ e._auchCRCHi[a]; o = e._auchCRCLo[a] } return [n, o]; } ```

I Don’t know if this helps someone to give any advise on how to correct this or on how to make scripts that will translate ok with the machine

Pepsi · January 23, 2026, 9:34am

The problem is the machine executes position commands in sequence and will only execute the next command after the previous one is finished. I just vibe coded a dodgy converter that you use in combination with the f21s sequence player to approximate a funscript.

Try it out, I can’t test it properly at the moment.