2 Lub Cav
Ntau lub suab los yog cov ntaub ntawv tuaj yeem ua si los ntawm FT800. Cov zis yog muab ua PWM
teeb liab ntawm ib tus pin, AUDIO_L. Muaj ob qhov suab, Lub suab Synthesizer thiab cov
Suab Playback.
-2.1 Suab Synthesizer
Cov teebmeem zoo muaj pre-loaded nyob rau hauv ib lub tsev qiv ntawv ROM yoj thiab tsis tas yuav siv ib yam ntawm FT800
RAM chaw. Cov neeg siv tswv yim feem ntau muaj peev xwm muab tau los ntawm cov teebmeem no, xws li nias
thaum lub on-screen khawm yog nias, DTMF tones rau xov tooj lossis lub tswb siab ceeb toom. Feem ntau
cov teebmeem yuav ua si ib zaug thiab tom qab ntawd nres. Lwm tus yuav ua si tsis tu ncua. Tag nrho cov npe ntawm tones thiab
cov nta muaj nyob hauv qab:
| Tus nqi | Nyhuv | Nruam | Suab kho | Tus nqi | Nyhuv | Nruam | Suab kho |
| 00h | Silence | Y | N | 32h | DTMF 2 | Y | N |
| 01h | square nthwv | Y | Y | 33h | DTMF 3 | Y | N |
| 02h | sine wave | Y | Y | 34h | DTMF 4 | Y | N |
| 03h | sawtooth yoj | Y | Y | 35h | DTMF 5 | Y | N |
| 04h | daim duab peb sab | Y | Y | 36h | DTMF 6 | Y | N |
| 05h | Beeping | Y | Y | 37h | DTMF 7 | Y | N |
| 06h | Tswb | Y | Y | 38h | DTMF 8 | Y | N |
| 07h | Warble | Y | Y | 39h | DTMF 9 | Y | N |
| 08h | Carousel | Y | Y | 40h | sau ntawv | N | Y |
| 10h | 1 luv luv kav | N | Y | 41h | xylophone | N | Y |
| 11h | 2 pips luv | N | Y | 42h | tuba | N | Y |
| 12h | 3 luv pips | N | Y | 43h | glockenspiel | N | Y |
| 13h | 4 luv pips | N | Y | 44h | hloov khoom nruab nrog | N | Y |
| 14h | 5 luv pips | N | Y | 45h | trumpet | N | Y |
| 15h | 6 daim ntawv luv luv | N | Y | 46h | piano | N | Y |
| 16h | 7 pips luv | N | Y | 47h | chimes | N | Y |
| 17h | 8 daim ntawv luv luv | N | Y | 48h | suab paj nruag lub thawv | N | Y |
| 18h | 9 pips luv | N | Y | 49h | tswb | N | Y |
| 19h | 10 pips luv | N | Y | 50h | nyem | N | N |
| 1Ah | 11 daim ntawv luv luv | N | Y | 51h | hloov | N | N |
| 1Bh | 12 luv pips | N | Y | 52h | cowbell | N | N |
| 1Ch | 13 luv pips | N | Y | 53h | nqis siab tshaj | N | N |
| 1Dh | 14 luv pips | N | Y | 54h | hihat | N | N |
| 1Eh | 15 luv pips | N | Y | 55h | kickdrum | N | N |
| 1Fh | 16 pips luv | N | Y | 56h | pop | N | N |
| 23h | DTMF # | Y | N | 57h | clack | N | N |
| 2Ch | DTMF * | Y | N | 58h | chack | N | N |
| 30h | DTMF 0 | Y | N | 60h | ruam | N | N |
| 31h | DTMF 1 | Y | N | 61h | unmute | N | N |
Muaj ntau ntawm cov teebmeem cia lub suab tswj (MIDI faj seeb), yog li ntau lub tones yuav tsum generated. Cov ntawv xeem MIDI ua yog siv:
| MIDI faj seeb | ANSI nco | Freq (Hz) | MIDI faj seeb | ANSI nco | Freq (Hz) |
| 21 | A0 | 27.5 | 65 | F4 | 349.2 |
| 22 | A # 0 | 29.1 | 66 | F # 4 | 370.0 |
| 23 | B0 | 30.9 | 67 | G4 | 392.0 |
| 24 | C1 | 32.7 | 68 | G # 4 | 415.3 |
| 25 | C # 1 | 34.6 | 69 | A4 | 440.0 |
| 26 | D1 | 36.7 | 70 | A # 4 | 466.2 |
| 27 | D # 1 | 38.9 | 71 | B4 | 493.9 |
| 28 | E1 | 41.2 | 72 | C5 | 523.3 |
| 29 | F1 | 43.7 | 73 | C # 5 | 554.4 |
| 30 | F # 1 | 46.2 | 74 | D5 | 587.3 |
| 31 | G1 | 49.0 | 75 | D # 5 | 622.3 |
| 32 | G # 1 | 51.9 | 76 | E5 | 659.3 |
| 33 | A1 | 55.0 | 77 | F5 | 698.5 |
| 34 | A # 1 | 58.3 | 78 | F # 5 | 740.0 |
| 35 | B1 | 61.7 | 79 | G5 | 784.0 |
| 36 | C2 | 65.4 | 80 | G # 5 | 830.6 |
| 37 | C # 2 | 69.3 | 81 | A5 | 880.0 |
| 38 | D2 | 73.4 | 82 | A # 5 | 932.3 |
| 39 | D # 2 | 77.8 | 83 | B5 | 987.8 |
| 40 | E2 | 82.4 | 84 | C6 | 1046.5 |
| 41 | F2 | 87.3 | 85 | C # 6 | 1108.7 |
| 42 | F # 2 | 92.5 | 86 | D6 | 1174.7 |
| 43 | G2 | 98.0 | 87 | D # 6 | 1244.5 |
| 44 | G # 2 | 103.8 | 88 | E6 | 1318.5 |
| 45 | A2 | 110.0 | 89 | F6 | 1396.9 |
| 46 | A # 2 | 116.5 | 90 | F # 6 | 1480.0 |
| 47 | B2 | 123.5 | 91 | G6 | 1568.0 |
| 48 | C3 | 130.8 | 92 | G # 6 | 1661.2 |
| 49 | C # 3 | 138.6 | 93 | A6 | 1760.0 |
| 50 | D3 | 146.8 | 94 | A # 6 | 1864.7 |
| 51 | D # 3 | 155.6 | 95 | B6 | 1975.5 |
| 52 | E3 | 164.8 | 96 | C7 | 2093.0 |
| 53 | F3 | 174,6 | 97 | C # 7 | 2217.5 |
| 54 | F # 3 | 185.0 | 98 | D7 | 2349.3 |
| 55 | G3 | 196.0 | 99 | D # 7 | 2489.0 |
| 56 | G # 3 | 207.7 | 100 | E7 | 2637.0 |
| 57 | A3 | 220.0 | 101 | F7 | 2793.8 |
| 58 | A # 3 | 233.1 | 102 | F # 7 | 2960.0 |
| 59 | B3 | 246.9 | 103 | G7 | 3136.0 |
| 60 | C4 | 261.6 | 104 | G # 7 | 3322.4 |
| 61 | C # 4 | 277.2 | 105 | A7 | 3520.0 |
| 62 | D4 | 293.7 | 106 | A # 7 | 3729.3 |
| 63 | D # 4 | 311.1 | 107 | B7 | 3951.1 |
| 64 | E4 | 329.6 | 108 | C8 | 4186.0 |
Lub suab synthesis yog tswj los ntawm cov npe hauv qab no:
REG_SOUND
o Teeb 31-16 = Tsis txhob tu
o Ntaus 15-8 = MIDI faj seeb (pitch)
o Khoom 7-0 Effect
REG_PLAY
o Khoom 31-1 = Tsis txhob tu
o Bit0 = Pib Ua Si / Ua Si
Sau ntawv = 1 mus pib ua si xaiv hauv REG_SOUND
Nyeem = 1 qhia tias qhov tshwm sim tam sim no ua si
Nyeem = 0 qhia tias qhov tshwm sim tiav lawm
REG_VOL_SOUND
o Khoom 31-8 = tsis saib xyuas
o Khoom 7-0 = tso zis
Nyeem thiab sau ntawv rau FT800 nco chaw yog siv los ntawm "hom xov tooj me me", qhov twg
tus thawj byte yuav yog qhov tseem ceeb kawg. Piv txwv, xav txog qhov kev txav thuam lub piano (0x46) ua si A4
(0x45). Cov ntaub ntawv ntawm SPI los yog I2C interface yuav txhaj ib lub Hoob Hwm Lus Sau ntawv nrog
cov ntaub ntawv nram qab no, ntawm kev txiav txim:
0x90 = Host Memory Sau ntawv hloov (0x80) ntxiv rau thawj qhov chaw nyob ntawm chaw sau npe (0x10)
0x24 = ob byte ntawm chaw sau npe
0x84 = peb byte ntawm chaw nyob
0x46 = piano nyhuv
0x45 = lus cim / suab = A4 (440Hz)
0x00 = tsis saib xyuas, yeem
0x00 = tsis saib xyuas, yeem
Nco ntsoov tias ob lub bytes dhau los tsis tas yuav sau, yog li 16-ntsis Lub Hauv Paus Tsev Kawm Ntawv Sau ntawv tuaj yeem ua tau
txaus siab rau qhov tseem ceeb uas yuav tsum muaj nyob rau hauv lub npe. Ntxiv kev piav qhia ntawm Lub Hoob Hwm Lus Sau, Hawm
Nco Kev Nyeem Ntawv thiab Hwm Lub Neej Hloov cov ntaub ntawv hloov tsheb muaj nyob hauv AN_240 FT800 Los ntawm
Av tuaj.
-2.2 Suab Ntaub Ntawv
Tej zaum yuav muaj kev siv qhov twg ntau dua li cov laus yooj yim synthesis tsim nyog. Rau
Piv txwv li ib lub suab los yog lwm cov ntawv tshaj tawm yuav tsum tau muab rau tus neeg siv
cov lus qhia. Qhov FT800 txhawb kev ua si ntawm cov ntaub ntawv hauv cov nram qab no ib leeg-channel (mono) tawm tswv yim:
8-khoom tau kos npe rau PCM - tsis muaj suab nrov
8-qhov khoom μLAW - cov duab tsis muaj linear
4-theem IMA-ADPCM - ntxiv compressed μLAW qhov twg txhua tus byte muaj ob tug 4-ntsis
kuaj
Tus FT800 muaj 256Kbytes ntawm kwv ram (RAM_G) tuav cov khoom yees duab (dluab thiab cov ntawv) thiab
suab khoom (cov suab kaw tseg). Lub chaw yuav tsum tswj hwm los ntawm tus tswv tsev MCU li ntawd
cov ntaub ntawv tsis muaj sau tseg kom txog rau thaum tom qab tsis tas yuav tsum tau ntxiv.
Cov ntaub ntawv audio yog loaded los ntawm lub Hoob Hwm Lus Sau xov tooj sau kev sib pauv mus rau qhov chaw thiab muaj
yuav tsum muaj 8-byte kws (64-ntsis).
Thaum ib lub suab xa mus rau hauv RAM_G nco, playback yog tswj los ntawm cov hauv qab no
sau npe:
REG_PLAYBACK_START
o Teeb 31-20 = tsis saib xyuas
o Khoom 19-0 = 20-ntsis pib qhov chaw nyob ntawm cov ntaub ntawv hauv RAM_G
REG_PLAYBACK_LENGTH
o Teeb 31-20 = tsis saib xyuas
o Khoom 19-0 = 20-ntsis ntev ntawm cov ntaub ntawv hauv RAM_G
REG_PLAYBACK_FREQ
o Teeb 31-16 = tsis saib xyuas
o Khoom 15-0 = 16-ntsis Playback sampling zaus zaus, hauv Hz
REG_PLAYBACK_FORMAT
o Teeb 31-2 = tsis saib xyuas
o Khoom 1-0 = 2-ntsis Playback hom
0 = Tawm, lossis tsis khov PCM
1 = μLaw
2 = ADPCM
3 = undefined
REG_PLAYBACK_LOOP
o Khoom 31-1 = tsis saib xyuas
o Bit 0 = 1-ntsis Playback style
0 = ua si ib zaug
1 = ua si tas li
REG_PLAYBACK_PLAY
o Khoom 31-1 = tsis saib xyuas
o Ntsuas 0 = Pib Ua Si / Ncig Ua Si
Sau ntawv = 0 los sis 1 mus pib ua si xaiv hauv REG_SOUND
Nyeem = 1 qhia tias cov ntaub ntawv yog tam sim no ua si
Nyeem = 0 qhia tias cov ntaub ntawv tiav
REG_PLAYBACK_READPTR
o Teeb 31-20 = tsis saib xyuas
o Khoom 19-0 = 20-ntsis pointer ntawm qhov chaw ua si tam sim no
REG_VOL_PB
o Khoom 31-8 = tsis saib xyuas
o Khoom 7-0 = tso zis
-2.2.1 Hloov Chaw Ua Haujlwm
FTDI muab cov ntaub ntawv tawm suab ua suab npe hu ua "AUD_CVT" mus nqa ib hom ntaub ntawv ntau thiab
tsim peb hom ntaub ntawv raws li FT800. Ib qhov txuas mus rau qhov chaw pabcuam no muaj nyob hauv
"Daim Ntawv Rhais A - Cov Lus Qhia" ntawm daim ntawv no.
Cov ntaub ntawv tau muab los ua ib qho nqaij nyoos (uncompressed) 16bit PCM, mono WAV ntaub ntawv. Xws li cov ntaub ntawv tau
raug tsim los ntawm ib qho kev pabcuam siv suab nrov, xws li Audacity. Thaum lub
cov ntaub ntawv muaj nyob, tsuas yog khiav cov dej taws ntawm kev hais kom ua:
aud_cvt -i inputfilename -f hom ntawv
qhov twg "hom ntawv" = 0 rau 8-ntsis kos npe rau PCM
= 1 rau 8-ntsis μLaw
= 2 rau 4-ntsis IMA ADPCM
Ib lub nplaub tshev nrog cov ntaub ntawv uas tau tsim yuav raug tsim. Cov ntaub ntawv no tuaj yeem siv los thauj hauv
RAM_G cheeb tsam ntawm lub FT800.
Lub tshuab ua suab paj nruag yuav tso tawm ib qho nqaij nyoos thiab compressed rau txhua hom ntawv xaiv. Nws
tej zaum yuav pab tau ntawm tus tswv tsev MCU khaws cov ntaub ntawv muab cov ntaub ntawv cia, thiab mam li nthuav lawv mus rau
RAM_G tsis thaum twg xav tau. Saib Tshooj 4 kom paub meej.