Initial variable pwm implementation

Author: damosvil

Bluejay.asm

@@ -194,7 +194,7 @@ Flag_Dir_Change_Brake		BIT	Flags1.5		; Set when braking before direction change
 Flag_High_Rpm				BIT	Flags1.6		; Set when motor rpm is high (Comm_Period4x_H less than 2)
 
 Flags2:					DS	1			; State flags. NOT reset upon motor_start
-;						BIT	Flags2.0
+Flag_Variable_Pwm_Bits		BIT	Flags2.0		; Set when programmed variable pwm
 Flag_Pgm_Dir_Rev			BIT	Flags2.1		; Set if the programmed direction is reversed
 Flag_Pgm_Bidir				BIT	Flags2.2		; Set if the programmed control mode is bidirectional operation
 Flag_32ms_Elapsed			BIT	Flags2.3		; Set when timer2 interrupt is triggered
@@ -976,6 +976,41 @@ t1_int_zero_rcp_checked:
 	mov	Temp6, Pwm_Limit_By_Rpm
 
 
+	; Check variable pwm
+	jnb Flag_Variable_Pwm_Bits, t1_int_variable_pwm_done
+
+	; If variable pwm, set pwm bits depending on PWM_CENTERED 1 [3-1] or 0 [2-0]
+	; and 8 bit rc pulse Temp2
+	; A < 40%
+	clr C
+	mov A, Temp2
+	subb	A, #100
+	jnc t1_int_variable_pwm_gt_40percent
+
+t1_int_variable_pwm_lt_40percent:
+	; rc pulse < 40% -> choose 96khz
+	mov PwmBitsCount, 2
+	sjmp t1_int_variable_pwm_centered
+
+t1_int_variable_pwm_gt_40percent:
+	subb	A, #50
+	jnc t1_int_variable_pwm_gt_60percent
+
+	; rc pulse < 60% -> choose 48khz
+	mov PwmBitsCount, 1
+	sjmp t1_int_variable_pwm_centered
+
+t1_int_variable_pwm_gt_60percent:
+	; rc pulse >= 60% -> choose 24khz
+	mov PwmBitsCount, 0
+
+t1_int_variable_pwm_centered:
+IF PWM_CENTERED == 0
+	inc PwmBitsCount
+ENDIF
+t1_int_variable_pwm_done:
+
+
 	; Limit PWM and scale pwm resolution and invert (duty cycle is defined inversely)
 	; depending on pwm bits count
 	mov A, PwmBitsCount
@@ -1045,7 +1080,11 @@ t1_int_pwm_limit_scale_dithering_pwm10bit_limited:
 t1_int_pwm_limit_scale_dithering_pwm10bit_scaled:
 	mov A, Temp4					; 11-bit low byte
 	cpl A
-	anl A, #((1 SHL (3 - 2)) - 1)	; Get index into dithering pattern table
+	anl A, #((1 SHL (3 - 2)) - 1)	; Get index [0,1] into dithering pattern table
+
+	; Multiplying by 4, select pattern [0, 4] on unified dithering pattern table
+	rl A
+	rl A
 
 	add A, #Dithering_Patterns
 	mov Temp1, A					; Reuse DShot pwm pointer since it is not currently in use.
@@ -1107,7 +1146,10 @@ t1_int_pwm_limit_scale_dithering_pwm9bit_limited:
 
 	mov A, Temp4					; 11-bit low byte
 	cpl A
-	anl A, #((1 SHL (3 - 1)) - 1)	; Get index into dithering pattern table
+	anl A, #((1 SHL (3 - 1)) - 1)	; Get index [0-3] into dithering pattern table
+
+	; Multiplying by 2, select pattern [0, 2, 4, 6] on unified dithering pattern table
+	rl A
 
 	add A, #Dithering_Patterns
 	mov Temp1, A					; Reuse DShot pwm pointer since it is not currently in use.
@@ -4092,31 +4134,7 @@ decode_pwm_dithering:
 	add	A, #0FFh					; Carry set if A is not zero
 	mov	Flag_Dithering, C			; Set dithering enabled
 
-	; Decode dithering pattern depending on PwmBitsCount
-	mov A, PwmBitsCount
-
-decode_pwm_dithering_pwm10bit:
-	cjne A, #2, decode_pwm_dithering_pwm9bit
-
-	; Initialize pwm dithering bit patterns
-	mov	Temp1, #Dithering_Patterns	; 1-bit dithering (10-bit to 11-bit)
-	mov	@Temp1, #00h				; 00000000
-	imov	Temp1, #55h				; 01010101
-	sjmp	decode_pwm_dithering_done
-
-decode_pwm_dithering_pwm9bit:
-	cjne A, #1, decode_pwm_dithering_pwm8bit
-
-	mov	Temp1, #Dithering_Patterns	; 2-bit dithering (9-bit to 11-bit)
-	mov	@Temp1, #00h				; 00000000
-	imov	Temp1, #11h				; 00010001
-	imov	Temp1, #55h				; 01010101
-	imov	Temp1, #77h				; 01110111
-	sjmp	decode_pwm_dithering_done
-
-decode_pwm_dithering_pwm8bit:
-	cjne A, #0, decode_pwm_dithering_done
-
+	; Initialize unified dithering pattern table
 	mov	Temp1, #Dithering_Patterns	; 3-bit dithering (8-bit to 11-bit)
 	mov	@Temp1, #00h				; 00000000
 	imov	Temp1, #01h				; 00000001
@@ -4127,7 +4145,7 @@ decode_pwm_dithering_pwm8bit:
 	imov	Temp1, #77h				; 01110111
 	imov	Temp1, #7fh				; 01111111
 
-decode_pwm_dithering_done:
+	; All decoding done
 	ret
 
 ;**** **** **** **** **** **** **** **** **** **** **** **** ****
@@ -4147,6 +4165,12 @@ calculate_pwm_bits:
     ; Let Temp1 = Pgm_Pwm_Freq / 24
 	mov Temp1, #Pgm_Pwm_Freq
 
+calculate_pwm_bits_variable_pwm_bits:
+	; If pwm is variable do not substract and set variable pwm flag
+	cjne	@Temp1, #0, calculate_pwm_bits_pwm96bits
+	setb	Flag_Variable_Pwm_Bits
+	sjmp	calculate_pwm_bits_pwm_decoded
+
 calculate_pwm_bits_pwm96bits:
 	; If pwm is 96 khz substract 2
 	cjne	@Temp1, #96, calculate_pwm_bits_pwm48bits