correct ini file offset sign (same value as in EEPROM), fix comments

see: OpenHantek/OpenHantek6022#352

Signed-off-by: Martin <[email protected]>

Author: Ho-Ro

CHANGELOG

@@ -1,3 +1,4 @@
+2022-10-18: update build process, create OpenHantek6022 header file with FW version [01b82fd]
 2022-07-29: update README, add status badges [00a965f]
 2022-07-29: upversion to 2.10.4 [6737826]
 2022-07-29: fix for #17 provided by guerby [b5fbe7b]

PyHT6022/Firmware/DSO6022BE/scope6022.inc

@@ -258,18 +258,18 @@ static BOOL set_samplerate( BYTE rate ) {
 }
 
 // new functon to set the calibration pulse frequency that allows
-// to set all possible frequencies between 40 Hz and 100 kHz
-// integer dividers of 2MHz Hz will be exact
+// to set all possible frequencies between 32 Hz and 100 kHz
+// integer dividers of 2MHz will be exact
 // frequencies between 40 Hz and 1000 Hz can be multiples of 10 Hz
-// frequencies between 100 Hz to 10 kHz can be multiples of 100 Hz
-// frequencies between 1 kHz to 100 kHz can be multiples of 1 kHz
+// frequencies between 100 Hz and 5500 Hz can be multiples of 100 Hz
+// frequencies between 1 kHz and 100 kHz can be multiples of 1 kHz
 // calibration frequency is coded into one byte parameter freq:
 // freq == 0   -> 100 Hz (compatibility to old sigrok coding)
 // freq 1..100 -> freq in kHz
 // freq 101, 102 -> not possible
 // freq == 103 -> 32 Hz (lowest possible frequency due to 16bit HW timer2)
-// freq 104..200  -> (value-100)*10 is freq in Hz
-// freq 201..255  -> (value-200)*100 is freq in Hz
+// freq 104..200  -> (value-100)*10 is freq in Hz (40, 50, ... 1000)
+// freq 201..255  -> (value-200)*100 is freq in Hz (100, 200, ... 5500)
 // e.g. 105 -> 50 Hz, 216 -> 1600 Hz, 20 -> 20 kHz
 //
 static BOOL set_calibration_pulse( BYTE freq ) {

examples/calibrate_6022.py

@@ -184,21 +184,23 @@ def read_avg( voltage_range, sample_rate=110, repeat = 1, samples = 12 * 1024 ):
     config.write( calFile )
     config.write( "\n;Created by tool 'calibrate_6022.py'\n\n" )
 
+    # offset as measured: values > 0 correct downwards, values < 0 correct upwards
     config.write( "[offset]\n" )
     for index, gainID in enumerate( gains ):
         voltID = V_div[ index ]
         if ( abs( offset1[ gainID ] ) <= 25 ):   # offset too high -> skip
-            config.write( "ch0\\%dmV=%6.2f\n" % ( voltID, -offset1[ gainID ] ) )
+            config.write( "ch0\\%dmV=%6.2f\n" % ( voltID, offset1[ gainID ] ) )
     for index, gainID in enumerate( gains ):
         voltID = V_div[ index ]
         if ( abs( offset2[ gainID ] ) <= 25 ):   # offset too high -> skip
-            config.write( "ch1\\%dmV=%6.2f\n" % ( voltID, -offset2[ gainID ] ) )
+            config.write( "ch1\\%dmV=%6.2f\n" % ( voltID, offset2[ gainID ] ) )
 
 
 for index, gainID in enumerate( gains ):
     # print( gains[index], offlo1[gainID], offlo2[gainID], offhi1[gainID], offhi2[gainID],  )
     # prepare eeprom content
     # store values in offset binary format (zero = 0x80, as in factory setup)
+    # offset as measured: values > 0x80 correct downwards, values < 0x80 correct upwards
     if ( abs( offlo1[ gainID ] ) <= 25 ):                           # offset too high -> skip
         ee_calibration[ 2 * index ] = 0x80 + offlo1[ gainID ]       # CH1 offset integer part
     if ( abs( offlo_1[ gainID ] ) <= 125 ):                         # frac part not plausible