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authorDeterminant <[email protected]>2017-09-21 15:50:48 -0400
committerDeterminant <[email protected]>2017-09-21 15:50:48 -0400
commitf6340e4d1f6bd9356830e0c73f0bd813912ea2cc (patch)
treeab6b1d658f1a03be0156e5354f8ee84ba4ec22bb /src
init
Diffstat (limited to 'src')
-rw-r--r--src/ds3231.rs77
-rw-r--r--src/i2c.rs101
-rw-r--r--src/main.rs96
3 files changed, 274 insertions, 0 deletions
diff --git a/src/ds3231.rs b/src/ds3231.rs
new file mode 100644
index 0000000..6ad75d8
--- /dev/null
+++ b/src/ds3231.rs
@@ -0,0 +1,77 @@
+extern crate stm32f103xx;
+use ::i2c::{I2C, TransDir};
+
+const DS3231_ADDR: u8 = 0b1101000;
+const DS3231_REG_SEC: u8 = 0x00;
+
+pub struct DS3231<'a> {
+ i2c: I2C<'a>
+}
+
+pub struct Date {
+ second: u8,
+ minute: u8,
+ hour: u8,
+ day: u8,
+ date: u8,
+ month: u8,
+ year: u8
+}
+
+impl<'a> DS3231<'a> {
+ pub fn new(i2c_reg: &'a stm32f103xx::i2c1::RegisterBlock) -> DS3231<'a> {
+ DS3231{i2c: I2C::new(i2c_reg)}
+ }
+
+ fn bcd2dec(bcd: u8) -> u8 {
+ (bcd >> 4) * 10 + (bcd & 0x0f)
+ }
+
+ fn dec2bcd(dec: u8) -> u8 {
+ ((dec / 10) << 4) | (dec % 10)
+ }
+
+ pub fn read_fulldate(&self) -> Date {
+ let mut buf: [u8; 7] = [0; 7];
+ let i2c = &self.i2c;
+ i2c.conf_ack(true); /* enable ack */
+ i2c.start(true, true); /* start condition (for writing reg addr) */
+ i2c.send_addr(DS3231_ADDR, TransDir::TRANSMITTER, true);
+ i2c.send(DS3231_REG_SEC, true);
+ /* restart condition (for reading val from the reg addr) */
+ i2c.start(true, true);
+ i2c.send_addr(DS3231_ADDR, TransDir::RECEIVER, true);
+ for i in 0..6 {
+ buf[i] = i2c.recv(true);
+ }
+ i2c.conf_ack(false); /* disable ack (send nack) */
+ buf[6] = i2c.recv(true);
+ i2c.stop(true);
+ Date{second: DS3231::bcd2dec(buf[0]),
+ minute: DS3231::bcd2dec(buf[1]),
+ hour: DS3231::bcd2dec(buf[2]),
+ day: DS3231::bcd2dec(buf[3]),
+ date: DS3231::bcd2dec(buf[4]),
+ month: DS3231::bcd2dec(buf[5]),
+ year: DS3231::bcd2dec(buf[6])}
+ }
+
+ pub fn write_fulldate(&self, date: &Date) {
+ let i2c = &self.i2c;
+ let buf: [u8; 7] = [DS3231::dec2bcd(date.second),
+ DS3231::dec2bcd(date.minute),
+ DS3231::dec2bcd(date.hour),
+ DS3231::dec2bcd(date.day),
+ DS3231::dec2bcd(date.date),
+ DS3231::dec2bcd(date.month),
+ DS3231::dec2bcd(date.year)];
+ i2c.conf_ack(true);
+ i2c.start(true, true); /* start condition for writing */
+ i2c.send_addr(DS3231_ADDR, TransDir::TRANSMITTER, true);
+ i2c.send(DS3231_REG_SEC, true);
+ for i in 0..7 {
+ i2c.send(buf[i], true);
+ }
+ i2c.stop(true);
+ }
+}
diff --git a/src/i2c.rs b/src/i2c.rs
new file mode 100644
index 0000000..8b6d4da
--- /dev/null
+++ b/src/i2c.rs
@@ -0,0 +1,101 @@
+#![allow(dead_code)]
+extern crate stm32f103xx;
+
+pub const EVENT_MASTER_STARTED: u32 = 0x00030001; /* BUSY, MSL and SB flag */
+pub const EVENT_MASTER_TRANSMITTER_MODE_SELECTED: u32 = 0x00070082; /* BUSY, MSL, ADDR, TXE and TRA flags */
+pub const EVENT_MASTER_RECEIVER_MODE_SELECTED: u32 = 0x00030002; /* BUSY, MSL and ADDR flags */
+pub const EVENT_MASTER_BYTE_RECEIVED: u32 = 0x00030040; /* BUSY, MSL and RXNE flags */
+pub const EVENT_MASTER_BYTE_TRANSMITTING: u32 = 0x00070080; /* TRA, BUSY, MSL, TXE flags */
+pub const EVENT_MASTER_BYTE_TRANSMITTED: u32 = 0x00070084; /* TRA, BUSY, MSL, TXE and BTF flags */
+
+const CR1_START_MASK: u16 = 0x0100;
+const CR1_STOP_MASK: u16 = 0x0200;
+const FLAGS_MASK: u32 = 0x00ffffff;
+
+pub struct I2C<'a> {
+ i2c: &'a stm32f103xx::i2c1::RegisterBlock,
+}
+
+pub enum TransDir {
+ TRANSMITTER,
+ RECEIVER
+}
+
+impl<'a> I2C<'a> {
+ pub fn new(reg: &'a stm32f103xx::i2c1::RegisterBlock) -> I2C<'a> {
+ I2C{i2c: reg}
+ }
+
+ pub fn start(&self, enable: bool, synced: bool) {
+ let i2c = &self.i2c;
+ unsafe {
+ match enable {
+ true => i2c.cr1.modify(|r, w| w.bits(r.bits()).start().set_bit()),
+ false => i2c.cr1.modify(|r, w| w.bits(r.bits()).start().clear_bit())
+ }
+ }
+ if synced {
+ while !self.check_event(EVENT_MASTER_STARTED) {}
+ }
+ }
+
+ pub fn stop(&self, enable: bool) {
+ let i2c = &self.i2c;
+ unsafe {
+ match enable {
+ true => i2c.cr1.modify(|r, w| w.bits(r.bits()).stop().set_bit()),
+ false => i2c.cr1.modify(|r, w| w.bits(r.bits()).stop().clear_bit())
+ }
+ }
+ }
+
+ pub fn conf_ack(&self, enable: bool) {
+ let i2c = &self.i2c;
+ unsafe {
+ match enable {
+ true => i2c.cr1.modify(|r, w| w.bits(r.bits()).ack().set_bit()),
+ false => i2c.cr1.modify(|r, w| w.bits(r.bits()).ack().clear_bit())
+ }
+ }
+ }
+
+ pub fn send_addr(&self, addr: u8, d: TransDir, synced: bool) {
+ let addr = (addr << 1) | match d {
+ TransDir::TRANSMITTER => 0,
+ TransDir::RECEIVER => 1
+ };
+ unsafe {
+ self.i2c.dr.write(|w| w.dr().bits(addr));
+ }
+ if synced {
+ match d {
+ TransDir::TRANSMITTER =>
+ while !self.check_event(EVENT_MASTER_TRANSMITTER_MODE_SELECTED) {},
+ TransDir::RECEIVER =>
+ while !self.check_event(EVENT_MASTER_RECEIVER_MODE_SELECTED) {}
+ }
+ }
+ }
+
+ pub fn send(&self, data: u8, synced: bool) {
+ unsafe {
+ self.i2c.dr.write(|w| w.dr().bits(data));
+ }
+ if synced {
+ while !self.check_event(EVENT_MASTER_BYTE_TRANSMITTED) {}
+ }
+ }
+
+ pub fn recv(&self, synced: bool) -> u8 {
+ if synced {
+ while !self.check_event(EVENT_MASTER_BYTE_RECEIVED) {}
+ }
+ self.i2c.dr.read().dr().bits()
+ }
+
+ pub fn check_event(&self, ev_mask: u32) -> bool {
+ let flags = self.i2c.sr1.read().bits() & 0xffff |
+ ((self.i2c.sr2.read().bits() & 0xffff) << 16) & FLAGS_MASK;
+ (flags & ev_mask) == ev_mask
+ }
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..168e55a
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,96 @@
+#![no_std]
+
+#[macro_use] extern crate stm32f103xx;
+extern crate cortex_m;
+use stm32f103xx::{GPIOA, RCC, SYST, I2C1};
+use cortex_m::peripheral::SystClkSource;
+mod i2c;
+mod ds3231;
+
+struct ShiftRegister<'a> {
+ gpioa: &'a stm32f103xx::gpioa::RegisterBlock,
+ width: u8,
+}
+
+static mut SR: Option<ShiftRegister> = None;
+static mut RTC: Option<ds3231::DS3231> = None;
+static mut N: u16 = 0;
+static mut DIGITS: [u8; 6] = [0; 6];
+
+fn systick_handler() {
+ unsafe {
+ /*
+ SR.as_mut().unwrap().output_bits(N as u32);
+ N += 1;
+ */
+ SR.as_mut().unwrap().output_bits(digits2bcds(&DIGITS[..]));
+ let mut i = 0;
+ let mut carry = 1;
+ while carry > 0 && i < DIGITS.len() {
+ DIGITS[i] += carry;
+ carry = if DIGITS[i] > 9 {DIGITS[i] = 0; 1} else {0};
+ i += 1;
+ }
+ }
+}
+
+//exception!(SYS_TICK, systick_handler);
+
+impl<'a> ShiftRegister<'a> {
+ fn new(g: &'a stm32f103xx::gpioa::RegisterBlock,
+ width: u8) -> ShiftRegister<'a> {
+ let this = ShiftRegister{gpioa: g, width: width};
+ this
+ }
+
+ fn output_bits(&mut self, bits: u32) {
+ let bsrr = &self.gpioa.bsrr;
+ for i in (0..self.width).rev() {
+ bsrr.write(|w| w.br1().reset());
+ /* feed the ser */
+ match (bits >> i) & 1 {
+ 0 => bsrr.write(|w| w.br0().reset()),
+ 1 => bsrr.write(|w| w.bs0().set()),
+ _ => panic!()
+ }
+ /* shift (trigger the sclk) */
+ bsrr.write(|w| w.bs1().set());
+ }
+ /* latch on (trigger the clk) */
+ bsrr.write(|w| w.br2().reset());
+ bsrr.write(|w| w.bs2().set());
+ }
+}
+
+fn digits2bcds(digs: &[u8]) -> u32 {
+ let mut res: u32 = 0;
+ for d in digs.iter().rev() {
+ res = (res << 4) | (*d as u32);
+ }
+ res
+}
+
+fn main() {
+
+ let gpioa: &stm32f103xx::gpioa::RegisterBlock = unsafe { &*GPIOA.get() };
+ let rcc: &stm32f103xx::rcc::RegisterBlock = unsafe { &*RCC.get() };
+ let i2c: &stm32f103xx::i2c1::RegisterBlock = unsafe { &*I2C1.get() };
+ let syst: &cortex_m::peripheral::SYST = unsafe { &*SYST.get() };
+
+ syst.set_clock_source(SystClkSource::Core);
+ syst.set_reload(100_000);
+ syst.enable_interrupt();
+ syst.enable_counter();
+ rcc.apb2enr.modify(|_, w| w.iopaen().enabled());
+ gpioa.crl.modify(|_, w|
+ w.mode0().output().cnf0().push()
+ .mode1().output().cnf1().push()
+ .mode2().output().cnf2().push());
+
+ unsafe {
+ RTC = Some(ds3231::DS3231::new(i2c));
+ SR = Some(ShiftRegister::new(gpioa, 24));
+ SR.as_mut().unwrap().output_bits(0);
+ let t = RTC.as_mut().unwrap().read_fulldate();
+ }
+}