From 539b6f2a04b6f1e5d972b74b1d4ca4d00bb65387 Mon Sep 17 00:00:00 2001
From: board707 <50185434+board707@users.noreply.github.com>
Date: Fri, 23 Aug 2024 13:44:26 +0300
Subject: [PATCH] Fix issue #115 - add clock settings for overclocked RP2040

---
 DMD_STM32a.cpp | 15 +++++++++------
 DMD_STM32a.h   |  8 +++++---
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/DMD_STM32a.cpp b/DMD_STM32a.cpp
index f0156e2..2b317c7 100644
--- a/DMD_STM32a.cpp
+++ b/DMD_STM32a.cpp
@@ -143,15 +143,18 @@ void DMD::initialize_timers(voidFuncPtr handler) {
 /*--------------------------------------------------------------------------------------*/
 void DMD::initialize_timers(voidFuncPtr handler) {
 
-	
+	// test PWM WRAP for overflow
+	if ((this->scan_cycle_len * 4 / this->pwm_clk_div) > TIM_MAX_RELOAD) {
+		this->pwm_clk_div = 1 + (this->scan_cycle_len * 4 / TIM_MAX_RELOAD);
+	}
 	this->scan_cycle_len = this->scan_cycle_len / this->pwm_clk_div;
 
-	
-
-	
-
+     // Adjust pio clk divider to not overflow panel CLK > 15 MHz
+	if (CYCLES_PER_MICROSECOND/ (4* this->pio_clkdiv) > MAX_PANEL_CLK) {
+		this->pio_clkdiv = 1+ CYCLES_PER_MICROSECOND/ (4* MAX_PANEL_CLK);
+	}
 
-	//pio configs
+   //pio configs
 	sm_data = pio_claim_unused_sm(pio, true);
 	//data_prog_offs = pio_add_program(pio, &dmd_out_program);
 	data_prog_offs = pio_add_dmd_out_program(pio, this->data_pins_cnt);
diff --git a/DMD_STM32a.h b/DMD_STM32a.h
index 574099b..091f445 100644
--- a/DMD_STM32a.h
+++ b/DMD_STM32a.h
@@ -3,7 +3,7 @@
 /*--------------------------------------------------------------------------------------
  DMD_STM32a.h  - advansed version of DMD_STM32.h
 
- ****** VERSION 1.1.3 ******
+ ****** VERSION 1.1.0 ******
 
  DMD_STM32.h  - STM32 port of DMD.h library
 
@@ -63,6 +63,8 @@ typedef uint32 PortType;
 #define TIM_MAX_RELOAD ((1 << 16) - 1)
 enum OE_PWM_Polarity{ OE_PWM_POSITIVE = TIMER_OC_MODE_PWM_1, OE_PWM_NEGATIVE = TIMER_OC_MODE_PWM_2 };
 #elif (defined(ARDUINO_ARCH_RP2040))
+#define TIM_MAX_RELOAD ((1 << 16) - 1)
+#define MAX_PANEL_CLK 15
 enum OE_PWM_Polarity { OE_PWM_POSITIVE = false, OE_PWM_NEGATIVE = true };
 typedef uint16_t PortType;
 #endif
@@ -466,10 +468,10 @@ class DMD : public Adafruit_GFX
 	PIO pio = pio0;
 	uint8_t sm_data = 0;
 	uint8_t sm_mux = 1;
-	const uint8_t pwm_clk_div = 10;
+	uint8_t pwm_clk_div = 10;
 	uint16_t data_prog_offs = 0;
 	pio_sm_config pio_config;
-	const uint8_t pio_clkdiv = 3;
+	uint8_t pio_clkdiv = 3;
 #endif