Imported from GitHub: mariosgit/VFD · commit 9c29bc6 · license MIT

Description

Drivers for a bunch of VFD displays, like the MN12832, ...

README

FreeDSP Controller with MN12832L

Usage

Top left encoder - Select EQ chanel

Top right encoder - turn EQ channel up/down

Center - Volume

Bottom Left - Crunchines

Bottom Right - Volumem press to toggle Mute states.

Main page

Center Encoder - Volume up/down Bottom Right Encoder - Volume up/down, Click toggles mute between Headphone and Speaker.

Not much more implemented so far.

Bugs

DSP does not boot itself !?. Press reset while panel has not started connecting - 4sec. Maybe put dsp-reset on the panel. Would be better for consistency when the prog is uploaded by the teensy.

XL6009

• voltage divider values are wrong. Old 2.2k / 91k -> New: 2k / 39k
• unstable, add input caps 10-47uF + 100nF, a 100nF over R39k removed 25Hz flicker dropouts !???

HC132 Oszilator Values are wrong. Old 2.7k 4.7n -> New: 2.7k / 100nF???

Check Value of R3 New: 4.7ohm.

Add Caps 100n, 10u

• close to Display

Add mounting holes ? Spacer for DSP board?

Fillet at outlines

Add rev polarity safety diode

Add Fuse, ~100mA

Add backlight (LEDs behing the knobs ?)

Add IR receiver and Ambient Lt sensor.

Todo

Control more stuff.

    // todo: fix 8th frequency, post level could be sum behind speaker eq to track max level ?!
    //       merge input level as 0 in the mux and remove the 2 inputLevels, frees 60 more instructions

Peak meter !?

Avoid output cliping/overflows ! https://ez.analog.com/dsp/sigmadsp/w/documents/14313/monitoring-average-and-instantaneous-signal-levels

Done

Spectrum Analyser

Using the provided 7 Band or Designer Things uses a lot of DSP prog !

PlanB:

Index selectable filter before the EQ level det. Try to sycle through these to get Spectral readings ?!

Saveload Write
Cell Name:  EQFilterIDX
Param Value:  0-8
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0x02

The first filter is flat, the others are 8 bands 100,200,400,800,1600,3200,6400,12800,Hz.

The emChecker loop sets these filters one after another and reads the levelmeter behind. This Results in a Spectrum analyser which seems to kind of work somewhat. Good enouth for the beginning.

References

SigmaStudio docs, recipes for filters

Evaluation of EQ settings versus Max Gain... and finding most usefull frequency and Q settings... The mute in front off the EQ will be used as a level to scale down by the max EQ gain.

The strangly vintage universe of SigmaDSP

Dear analog devices, you web resources did'nt age so well.

Documentation of the DSP blocks... best to search with Ggl https://wiki.analog.com/resources/tools-software/sigmastudio/toolbox/leveldetectorslookuptables/singlebandleveldetector

Reading Levels and other tutorials ... https://ez.analog.com/dsp/sigmadsp/w/documents/14313/monitoring-average-and-instantaneous-signal-levels

SigmaStudio logs

SoftClip

Link SigmaWiki SoftClip:

Block Write
Time:  17:31:17 - 173ms
IC:  IC 1
Cell Name:  SoftClip1
Param Name:  SoftClipAlgG21alpha
Param Address:  0x0062
Param Value:  10
Bytes:  4
Param Data:
0x05, 	0x00, 	0x00, 	0x00

Change to "9" which is off. Range is 0.1 - 10. You always write the value and it's reciproke, so 1/9. SigStud does a block write here. Values 3,4 are static.

Cell Name:  SoftClip1
Param Name:  SoftClipAlgG21alpha
Param Address:  0x0062
Param Value:  9
Bytes:  4
Param Data: 0x04, 	0x80, 	0x00, 	0x00

Cell Name:  SoftClip1
Param Name:  SoftClipAlgG21alpham1
Param Address:  0x0063
Param Value:  0.111111164093018
Bytes:  4
Param Data:
0x00, 	0x0E, 	0x38, 	0xE4

// constant.. ?

Cell Name:  SoftClip1
Param Name:  SoftClipAlgG21onethird
Param Address:  0x0064
Param Value:  0.333333373069763
Bytes:  4
Param Data: 0x00, 	0x2A, 	0xAA, 	0xAB

Cell Name:  SoftClip1
Param Name:  SoftClipAlgG21twothird
Param Address:  0x0065
Param Value:  0.666666626930237
Bytes:  4
Param Data: 0x00, 	0x55, 	0x55, 	0x55

turn to bypass

Cell Name:  Nx2-1
Param Name:  StMuxSwSlew1coeffname
Param Address:  0x0097
Param Value:  0
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0x00

turn switch on

Cell Name:  Nx2-1
Param Name:  StMuxSwSlew1coeffname
Param Address:  0x0097
Param Value:  1
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0x01

Turning the Crossover to 110Hz

It writes B0,B1,A1 only ? Yes, first order lowpass and highpass only change these, the others are 0 or 1...

ah and the low side is inverted due to phase...

lowpass 110

bs	as
0.007148143726676948	(1.0)
0.007148143726676948	-0.9857037125466461*-1
0	0

highpass 110

bs	as
0.9928518562733231	(1.0)
-0.992851856273323	-0.9857037125466461*-1
0	0

ok, SP1 are the lowpasses SP2 the highpasses ??? do not see this ! and the postfix _0 _1 is the channel, puh

Arrrg :-O , in the header it's named clearly as MOD_CROSSOVER1_ALG1_LOW_FILT1_PARAMB0_ADDR

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1B0_0
Param Address:  0x00FA
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1B1_0
Param Address:  0x00FB
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1A1_0
Param Address:  0x00FC
Param Value:  0.985703706741333

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1B0_1
Param Address:  0x00FD
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1B1_1
Param Address:  0x00FE
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP1A1_1
Param Address:  0x00FF
Param Value:  0.985703706741333

------SP2

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2B0_0
Param Address:  0x0107
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2B1_0
Param Address:  0x0108
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2A1_0
Param Address:  0x0109
Param Value:  0.985703706741333

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2B0_1
Param Address:  0x010A
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2B1_1
Param Address:  0x010B
Param Value:  0.0071481466293335

Cell Name:  Crossover1
Param Name:  CrossoverFilter2WayAlgSP2A1_1
Param Address:  0x010C
Param Value:  0.985703706741333

invert an/aus, mhm ok it's another param, does not effect the biquads

// on
Param Name:  CrossoverFilter2WayAlgSP1LowInvert
Param Address:  0x00F9
Param Value:  -1

Param Name:  CrossoverFilter2WayAlgSP2LowInvert
Param Address:  0x0106
Param Value:  -1

//off
Param Name:  CrossoverFilter2WayAlgSP1LowInvert
Param Address:  0x00F9
Param Value:  1

Param Name:  CrossoverFilter2WayAlgSP2LowInvert
Param Address:  0x0106
Param Value:  1

InputMixer

turn up chanel 0/1

Safeload Write
Time:  23:09:22 - 120ms
IC:  IC 1
Cell Name:  NxM Mixer1
Param Name:  NxNMixer1940Alg1_01_01
Param Address:  0x0017
Param Value:  1.99526226520538
Bytes:  4
Param Data:
0x00, 	0xFF, 	0x64, 	0xC1

Safeload Write
Time:  23:09:39 - 664ms
IC:  IC 1
Cell Name:  NxM Mixer1
Param Name:  NxNMixer1940Alg1_00_00
Param Address:  0x0011
Param Value:  1.99526226520538
Bytes:  4
Param Data:
0x00, 	0xFF, 	0x64, 	0xC1

Switching Sinus on off

Second value is freq ? 65Hz

off

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401mask
Param Address:  0x0003
Param Value:  255
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0xFF

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401increment
Param Address:  0x0004
Param Value:  0.0027087926864624
Bytes:  4
Param Data:0x00, 	0x00, 	0x58, 	0xC3

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401ison
Param Address:  0x0005
Param Value:  0
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0x00

on

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401mask
Param Address:  0x0003
Param Value:  255
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0xFF

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401increment
Param Address:  0x0004
Param Value:  0.0027087926864624
Bytes:  4
Param Data: 0x00, 	0x00, 	0x58, 	0xC3

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401ison
Param Address:  0x0005
Param Value:  1
Bytes:  4 Param Data: 0x00, 	0x80, 	0x00, 	0x00

freq 80Hz

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401mask
Param Address:  0x0003
Param Value:  255
Bytes:  4
Param Data:
0x00, 	0x00, 	0x00, 	0xFF

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401increment
Param Address:  0x0004
Param Value:  0.00333333015441895
Bytes:  4
Param Data: 0x00, 	0x00, 	0x6D, 	0x3A

Safeload Write
Cell Name:  Tone1
Param Name:  sin_lookupAlg19401ison
Param Address:  0x0005
Param Value:  0
Bytes:  4
Param Data: 0x00, 	0x00, 	0x00, 	0x00

Peak and Avg Readback

Read Init
Cell Name:  ReadBackUserEQ
Param Name:  ReadBackAlg1
Param Address:  0x081A
Bytes:  2
Param Data:   0x05, 	0xB2

Read Request
Cell Name:  ReadBackUserEQ
Param Name:  ReadBackAlg1
Param Address:  0x081A
Bytes:  3

Read Result
Cell Name:  ReadBackUserEQ
Param Name:  ReadBackAlg1
Param Address:  0x081A
Bytes:  1
Param Data:   0x10, 	0x52, 	0x1D

Comparing Biquad calculators...

SigmaStudio Bandpass produces this 100Hz BW:2

• b0 = 0.00972211360931396
• b1 = 0
• b2 = -0.00972211360931396
• a1 = 1.98038613796234
• a2 = -0.980555891990662

exactly what teensy audio biquad.h produces :)

earlevel eng.. a und b are swaped, use a results as b bi[0,1,2] , use b results inverted as a bi[3,4]