From 8d698e0ae05a4bdf65f5252a9178fb545e8f0b89 Mon Sep 17 00:00:00 2001
From: Michael Dryden <mdryden@chem.utoronto.ca>
Date: Wed, 4 Feb 2015 17:51:24 -0500
Subject: [PATCH] Implemented SWV using timed single ADC conversions.
---
DSTAT-temp/src/experiment.c | 54 ++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 22 deletions(-)
diff --git a/DSTAT-temp/src/experiment.c b/DSTAT-temp/src/experiment.c
index 4786026..53070d1 100644
--- a/DSTAT-temp/src/experiment.c
+++ b/DSTAT-temp/src/experiment.c
@@ -801,35 +801,31 @@ void swv_experiment(int16_t start, int16_t stop, uint16_t step, uint16_t pulse_h
direction = 0;
tc_enable(&TCF0);
+ tc_enable(&TCC0);
frequency *= 2; //compensate for half-period triggers
//calculate time to ADC trigger
period = ceil((1/(double)frequency)*F_CPU);
-
- if (direction == 1)
- max5443_set_voltage1(dacindex+dacindex_pulse_height);
- else
- max5443_set_voltage1(dacindex-dacindex_pulse_height);
+ uint32_t adc_period = ceil(((1/(double)frequency)-(double)(sample_delay_ms_100div/1e5))*F_CPU);
set_timer_period(period, &TCF0);
+ set_timer_period(adc_period, &TCC0);
ads1255_wakeup();
- ads1255_rdatac();
- ads1255_sync();
+ ads1255_standby();
volt_exp_start();
do{
TCF0.CNT = 0;
- while (!tc_is_overflow(&TCF0));
- ads1255_wakeup(); //synchronize ADC
- TCF0.CNT = 0;
+ TCC0.CNT = 0;
if (_swv_singledir(dacindex_start, dacindex_stop, dacindex_pulse_height, dacindex_step, direction))
goto aborting; //function will return non-zero if abort called over USB
if (scans > 0){ //non-cyclic mode skips out after one direction
TCF0.CNT = 0;
+ TCC0.CNT = 0;
if (_swv_singledir(dacindex_stop, dacindex_start, dacindex_pulse_height, dacindex_step, !direction)) //swap start and stop and invert direction for second half of scan
goto aborting;
}
@@ -845,6 +841,9 @@ void swv_experiment(int16_t start, int16_t stop, uint16_t step, uint16_t pulse_h
tc_write_clock_source(&TCF0, TC_CLKSEL_OFF_gc);
tc_disable(&TCF0);
TCF0.CNT = 0;
+ tc_write_clock_source(&TCC0, TC_CLKSEL_OFF_gc);
+ tc_disable(&TCC0);
+ TCC0.CNT = 0;
ads1255_standby();
return;
@@ -871,34 +870,45 @@ uint8_t _swv_singledir (uint16_t dacindex, uint16_t dacindex_stop, uint16_t daci
while ((dacindex <= dacindex_stop && direction == 1) || (dacindex >= dacindex_stop && direction == 0)){
tc_clear_overflow(&TCF0);
+ tc_clear_overflow(&TCC0);
- while (!tc_is_overflow(&TCF0)){ //convert continuously until tc overflow - datum is last collected point
- while (ioport_pin_is_low(IOPORT_CREATE_PIN(PORTD, 5))); //wait for next valid datum
- while (ioport_pin_is_high(IOPORT_CREATE_PIN(PORTD, 5)));
- forward = ads1255_read_fast24();
+ while (!tc_is_overflow(&TCC0)){ //ADC tc overflow
if (udi_cdc_is_rx_ready()){ //check for abort signal over USB
if (getchar() == 'a')
return 1;
}
}
-
+
+ ads1255_wakeup();
+ while (ioport_pin_is_high(IOPORT_CREATE_PIN(PORTD, 5)));
+ forward = ads1255_read_single24();
+ ads1255_standby();
+
+ while (!tc_is_overflow(&TCF0)); //wait for end of half-cycle
+ TCC0.CNT = 0;
+
if (direction == 1) //switch voltage to other half of cycle
max5443_set_voltage1(dacindex-dacindex_pulse_height);
else
max5443_set_voltage1(dacindex+dacindex_pulse_height);
tc_clear_overflow(&TCF0); //reset timer OVF
+ tc_clear_overflow(&TCC0);
- while (!tc_is_overflow(&TCF0)){ //wait for tc overflow
- while (ioport_pin_is_low(IOPORT_CREATE_PIN(PORTD, 5))); //wait for next valid datum
- while (ioport_pin_is_high(IOPORT_CREATE_PIN(PORTD, 5)));
- reverse = ads1255_read_fast24();
-
- if (udi_cdc_is_rx_ready()){
+ while (!tc_is_overflow(&TCC0)){ //ADC tc overflow
+ if (udi_cdc_is_rx_ready()){ //check for abort signal over USB
if (getchar() == 'a')
- return 1;
+ return 1;
}
}
+
+ ads1255_wakeup();
+ while (ioport_pin_is_high(IOPORT_CREATE_PIN(PORTD, 5)));
+ reverse = ads1255_read_single24();
+ ads1255_standby();
+
+ while (!tc_is_overflow(&TCF0)); //wait for end of half-cycle
+ TCC0.CNT = 0;
lastindex = dacindex;
--
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