Diff: a4960.cpp

Revision:

11:4251b62991ac

diff -r af76616e4d75 -r 4251b62991ac a4960.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/a4960.cpp	Tue May 16 19:31:49 2017 +0000
@@ -0,0 +1,82 @@
+#include "a4960.h"
+
+a4960::a4960() : SPI(NRF_SPI1), _cs_pin(P0_10), _blink_pin(P0_4), _PWM_pin(P0_15)
+{
+    PWM_freq = 20000.0;
+    PWM_duty = 1;
+    motor_started = false;
+
+    _config[0] = (0x0 << 10) | (0x8 << 6) | (0x14); // 50 us comm blank time, 2.4 us blank time, 200 ns deadtime
+    _config[1] = (0x7 << 6) | (0x0); // Vri = 100% Vref, Vdsth = 800mV
+    _config[2] = (0x10); // 35.6 us current control time
+    _config[3] = (0x0 << 8) | (0x5 << 4) | (0x4); // current limited, 50% current for hold, 18ms hold time
+    _config[4] =  (0x15 << 4) | (0x4); // 0.8ms min comm time, 24 ms start comm time
+    _config[5] = (0x0 << 8) | (0x8 << 4) | (0x0); // 16.875deg phase adv, 100% ramp current, 0.4ms ramp rate
+    _config[6] = (0x0); // fault detection all on
+    _config[7] = (0x0 << 10) | (0x4 << 7) | (0x0 << 6) | (0x0 << 4) | (0x1 << 3) | (0x0 << 2) | (0x0 << 1) | (0x0);
+    // auto BEMF hyst, 3.2us zx det window, no stop on fail, DIAG pin = fault, restart on loss of sync, brake off, forward, coast
+    
+    SPI_init();
+}
+
+void a4960::SPI_init()
+{
+    // initialize pins
+    _cs_pin = 1;
+    _blink_pin = 1;
+    _PWM_pin.period(1/PWM_freq);
+    _PWM_pin.write(PWM_duty);
+    // initialize SPI connection
+    SPI.begin(P0_8, P0_9, P0_11);//SCK, MOSI, MOSI
+    // set registers to default config
+    for (int i = 0; i < 8; i++) {
+        write_to_a4960(i, _config[i]);
+    }
+    // turn off pin to indicate initialization complete
+    _blink_pin = 0;
+}
+void a4960::write_to_a4960(uint8_t addr, uint16_t msg)
+{
+    // split 16-bit message to a4960 into two 8-bit messages
+    uint8_t ms_half;
+    uint8_t ls_half;
+
+    // ---- 1st message (bits 15 - 8)
+    // 3 bit address
+    ms_half = addr << 5;
+    // 12 bit message
+    // shift message to get rid of 8 LSB on the end and OR
+    // the write bit and the
+    // 4 remaining bits into the first-half msg
+    ms_half = ms_half | 1 << 4 | (uint8_t)(msg>>8);
+    // ---- 2nd message (bits 7 - 0)
+    ls_half = (uint8_t)(msg);
+
+    // pull to active low
+    _cs_pin = 0;
+    wait_us(200);
+
+    // transfer the two messages halves, MSB first
+    SPI.transfer(ms_half);
+    SPI.transfer(ls_half);
+
+    // wait and pull CS line back to inactive high
+    wait_us(200);
+    _cs_pin = 1;
+}
+
+void a4960::write_run(void)
+{
+    write_to_a4960(7, _config[7] | 1);
+}
+
+void a4960::write_brake(void)
+{
+    write_to_a4960(7, _config[7]);
+}
+
+
+
+
+
+