From 85df63591a2024cf809ac8082804e9f1613958bb Mon Sep 17 00:00:00 2001
From: Anton Pozharskiy <apozharski@gmail.com>
Date: Tue, 4 Aug 2020 12:50:50 -0400
Subject: [PATCH] Unhiding twi functionality
---
libraries/Wire/src/utility/twi.c | 20 ++++++++++----------
libraries/Wire/src/utility/twi.h | 2 +-
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/libraries/Wire/src/utility/twi.c b/libraries/Wire/src/utility/twi.c
index e6e45e54..a3231462 100644
--- a/libraries/Wire/src/utility/twi.c
+++ b/libraries/Wire/src/utility/twi.c
@@ -175,8 +175,11 @@ uint8_t TWI_MasterReady(void)
* Sets the baud rate used by TWI Master.
*
* \param frequency The required baud.
+ *
+ * \retval 0 If baud set correctly
+ * \retval 1 If baud not set due to being too high. > 1MHz
*/
-void TWI_MasterSetBaud(uint32_t frequency){
+uint8_t TWI_MasterSetBaud(uint32_t frequency){
// Formula is: BAUD = ((F_CLKPER/frequency) - F_CLKPER*T_RISE - 10)/2;
// Where T_RISE varies depending on operating frequency...
@@ -184,26 +187,23 @@ void TWI_MasterSetBaud(uint32_t frequency){
uint16_t t_rise;
- if(frequency < 200000){
- frequency = 100000;
+ if(frequency <= 100000){
t_rise = 1000;
- } else if (frequency < 800000){
- frequency = 400000;
+ } else if (frequency <= 400000){
t_rise = 300;
- } else if (frequency < 1200000){
- frequency = 1000000;
+ } else if (frequency <= 1000000){
t_rise = 120;
} else {
- frequency = 100000;
- t_rise = 1000;
+ return 1;
}
uint32_t baud = ((F_CPU_CORRECTED/frequency) - (((F_CPU_CORRECTED*t_rise)/1000)/1000)/1000 - 10)/2;
TWI0.MBAUD = (uint8_t)baud;
+ return 0;
}
/*! \brief TWI write transaction.
@@ -781,4 +781,4 @@ ISR(TWI0_TWIM_vect){
ISR(TWI0_TWIS_vect){
TWI_SlaveInterruptHandler();
-}
\ No newline at end of file
+}
diff --git a/libraries/Wire/src/utility/twi.h b/libraries/Wire/src/utility/twi.h
index a5c01e19..ceb279a1 100644
--- a/libraries/Wire/src/utility/twi.h
+++ b/libraries/Wire/src/utility/twi.h
@@ -75,7 +75,7 @@ void TWI_Flush(void);
void TWI_Disable(void);
TWI_BUSSTATE_t TWI_MasterState(void);
uint8_t TWI_MasterReady(void);
-void TWI_MasterSetBaud(uint32_t frequency);
+uint8_t TWI_MasterSetBaud(uint32_t frequency);
uint8_t TWI_MasterWrite(uint8_t slave_address,
uint8_t *write_data,
uint8_t bytes_to_write,