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For chips with handle.Init.Timing, do not try to guess it 

Those chips will need to #define I2Cx_100KHZ_TIMING in variant.h to work.
This commit is contained in:
Daniel Fekete 2017-04-29 06:43:10 +02:00
parent 0a2f0bbd72
commit 9ce5253c8c
1 changed files with 15 additions and 31 deletions
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46
STM32/libraries/Wire/src/Wire.cpp
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@ -131,38 +131,22 @@ void TwoWire::setClock(uint32_t frequency) {
handle.Init.ClockSpeed = frequency;
handle.Init.DutyCycle = I2C_DUTYCYCLE_2;
#else
uint32_t clock_source = stm32_apb_clock_freq(handle.Instance);
//Timing values from AN4235 / I2C Timing Configuration Tool
//TODO reverse engineer the timing tool?
//TODO get timing values for 400Khz
//Timing values for 100Khz speed for some common I2C clock sources
if (frequency == 100000) {
if (clock_source == 16000000) {
handle.Init.Timing = 0x00303D5B;
} else if (clock_source == 32000000) {
handle.Init.Timing = 0x00707CBB;
} else if (clock_source == 36000000) {
handle.Init.Timing = 0x00808CD2;
} else if (clock_source == 50000000) {
handle.Init.Timing = 0x00C0EAFF;
} else if (clock_source == 72000000) {
handle.Init.Timing = 0x10808DD3;
} else if (clock_source == 80000000) {
handle.Init.Timing = 0x10909CEC;
} else if (clock_source == 100000000) {
handle.Init.Timing = 0x10C0ECFF;
} else if (clock_source == 168000000) {
handle.Init.Timing = 0x60505F8C;
} else if (clock_source == 216000000) {
handle.Init.Timing = 0xA0404E72;
} else {
return;
//TODO error handler?
}
} else {
// Use 100Khz default for now...
}
// I2C1_100KHZ_TIMING needs to be #defined in variant.h for these boards
// Open STM32CubeMX, select your chip, clock configuration according to systemclock_config.c
// Enable all I2Cs, go to I2Cx configuration, parameter settings, copy the Timing value.
#ifdef I2C1
if (handle.Instance == I2C1) handle.Init.Timing = I2C1_100KHZ_TIMING;
#endif
#ifdef I2C2
if (handle.Instance == I2C2) handle.Init.Timing = I2C2_100KHZ_TIMING;
#endif
#ifdef I2C3
if (handle.Instance == I2C3) handle.Init.Timing = I2C3_100KHZ_TIMING;
#endif
#ifdef I2C4
if (handle.Instance == I2C4) handle.Init.Timing = I2C4_100KHZ_TIMING;
#endif
#endif