From 84ae7ae2a86cfadc219acb2d21c65fa70a63fd7a Mon Sep 17 00:00:00 2001
From: Alberto Nidasio <alberto.nidasio@skywarder.eu>
Date: Sat, 1 Jul 2023 17:14:15 +0200
Subject: [PATCH] [ADS131] Added documentation throughout the code and improved
self test sequence
---
src/shared/sensors/ADS131M04/ADS131M04.cpp | 154 +++++++++++++++------
src/shared/sensors/ADS131M04/ADS131M04.h | 78 +++++++++--
src/shared/sensors/ADS131M08/ADS131M08.cpp | 152 ++++++++++++++------
src/shared/sensors/ADS131M08/ADS131M08.h | 78 +++++++++--
src/tests/sensors/test-ads131m04.cpp | 4 +-
src/tests/sensors/test-ads131m08.cpp | 4 +-
6 files changed, 357 insertions(+), 113 deletions(-)
diff --git a/src/shared/sensors/ADS131M04/ADS131M04.cpp b/src/shared/sensors/ADS131M04/ADS131M04.cpp
index bb614f6ce..727ed16a8 100644
--- a/src/shared/sensors/ADS131M04/ADS131M04.cpp
+++ b/src/shared/sensors/ADS131M04/ADS131M04.cpp
@@ -40,7 +40,7 @@ ADS131M04::ADS131M04(SPIBusInterface &bus, miosix::GpioPin cs,
ADS131M04::ADS131M04(SPISlave spiSlave) : spiSlave(spiSlave)
{
- // Initialize the channel configurations
+ // Initialize the channel configurations to the default values
for (int i = 0; i < CHANNELS_NUM; i++)
{
channelsPGAGain[i] = PGA::PGA_1;
@@ -87,7 +87,10 @@ bool ADS131M04::reset()
void ADS131M04::calibrateOffset()
{
- // Reset all offsets and gains, otherwise the calibration would be wrong
+ // The device internal data chain firsts subtracts the offset and then
+ // multiplies for the gain. To calibrate the offset we first reset it, then
+ // take some samples and apply the average as the new offset.
+ // So we need to reset the offset and gain
for (int i = 0; i < CHANNELS_NUM; i++)
{
setChannelOffsetImpl(static_cast<Channel>(i), 0);
@@ -117,17 +120,32 @@ void ADS131M04::calibrateOffset()
realSampleCount++;
}
- for (int i = 0; i < CHANNELS_NUM; i++)
- {
- // Compute the average
- averageValues[i] /= realSampleCount;
- LOG_INFO(logger, "Channel {} average offset: {}", i,
- averageValues[i] * getLSBSizeFromGain(channelsPGAGain[i]));
- // The new offset is the average value
- setChannelOffset(static_cast<Channel>(i), averageValues[i]);
+ if (realSampleCount == 0)
+ {
+ LOG_ERR(logger, "Calibration failed, no valid samples");
+ }
+ else
+ {
+ for (int i = 0; i < CHANNELS_NUM; i++)
+ {
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+ LOG_INFO(logger, "Channel {} average offset: {}", i,
+ averageValues[i] * getLSBSizeFromGain(channelsPGAGain[i]));
+
+ // Set the new offset only if valid, otherwise keep the old one
+ if (averageValues[i] != 0)
+ {
+ channelsOffset[i] = averageValues[i];
+ }
+ }
+ }
- // Reset the gain as it was before
+ // Update the offset values and reset the gain as it was before
+ for (int i = 0; i < CHANNELS_NUM; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), channelsOffset[i]);
setChannelGainCalibrationImpl(static_cast<Channel>(i), channelsGain[i]);
}
}
@@ -181,8 +199,7 @@ void ADS131M04::disableGlobalChopMode()
bool ADS131M04::selfTest()
{
- float voltage[CHANNELS_NUM] = {0};
- bool success = true;
+ bool success = true;
// Reset PGA, offsets and gains and connect the positive test signal
for (int i = 0; i < CHANNELS_NUM; i++)
@@ -194,31 +211,59 @@ bool ADS131M04::selfTest()
}
// Take some samples
+ int32_t averageValues[CHANNELS_NUM] = {0};
+ int realSampleCount = 0;
for (int i = 0; i < SELF_TEST_SAMPLES; i++)
{
+ // Wait for a sample to be ready
Thread::sleep(4);
- auto newSample = sampleImpl();
+
+ // Sample the channels
+ int32_t rawValues[CHANNELS_NUM];
+ if (!readSamples(rawValues))
+ {
+ // If the CRC failed we skip this sample
+ continue;
+ }
for (int j = 0; j < CHANNELS_NUM; j++)
{
- voltage[j] += newSample.voltage[j];
+ averageValues[j] += rawValues[j];
}
+
+ realSampleCount++;
}
- // Check the values
- for (int i = 0; i < CHANNELS_NUM; i++)
+ if (realSampleCount == 0)
{
- // Compute the average
- voltage[i] /= SELF_TEST_SAMPLES;
-
- // Check if the value is in the acceptable range
- if (voltage[i] < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ LOG_ERR(logger,
+ "Failed self test with positive DC signal, no valid samples");
+ success = false;
+ }
+ else
+ {
+ // Check the values
+ for (int i = 0; i < CHANNELS_NUM; i++)
{
- LOG_ERR(logger,
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+
+ // Convert the value to Volts
+ float volts = averageValues[i] * getLSBSizeFromGain(PGA::PGA_1);
+
+ // Check if the value is in the acceptable range
+ if (volts < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ {
+ LOG_ERR(
+ logger,
"Self test failed on channel {} on positive test signal, "
"value was {}",
- i, voltage[i]);
- success = false;
+ i, volts);
+ success = false;
+ }
+
+ // Reset the raw value
+ averageValues[i] = 0;
}
}
@@ -229,40 +274,58 @@ bool ADS131M04::selfTest()
}
// Take some samples
+ realSampleCount = 0;
for (int i = 0; i < SELF_TEST_SAMPLES; i++)
{
+ // Wait for a sample to be ready
Thread::sleep(4);
- auto newSample = sampleImpl();
+
+ // Sample the channels
+ int32_t rawValues[CHANNELS_NUM];
+ if (!readSamples(rawValues))
+ {
+ // If the CRC failed we skip this sample
+ continue;
+ }
for (int j = 0; j < CHANNELS_NUM; j++)
{
- voltage[j] += newSample.voltage[j];
+ averageValues[j] += rawValues[j];
}
+
+ realSampleCount++;
}
- // Check the values
- for (int i = 0; i < CHANNELS_NUM; i++)
+ if (realSampleCount == 0)
{
- // Compute the average
- voltage[i] /= SELF_TEST_SAMPLES;
-
- // Check if the value is in the acceptable range
- if (voltage[i] > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ LOG_ERR(logger,
+ "Failed self test with positive DC signal, no valid samples");
+ success = false;
+ }
+ else
+ {
+ // Check the values
+ for (int i = 0; i < CHANNELS_NUM; i++)
{
- LOG_ERR(logger,
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+
+ // Convert the value to Volts
+ float volts = averageValues[i] * getLSBSizeFromGain(PGA::PGA_1);
+
+ // Check if the value is in the acceptable range
+ if (volts > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ {
+ LOG_ERR(
+ logger,
"Self test failed on channel {} on negative test signal, "
"value was {}",
- i, voltage[i]);
- success = false;
+ i, volts);
+ success = false;
+ }
}
}
- // If any channel failed we return false
- if (!success)
- {
- return false;
- }
-
// Reset channels previous configuration
for (int i = 0; i < CHANNELS_NUM; i++)
{
@@ -272,7 +335,8 @@ bool ADS131M04::selfTest()
setChannelInput(static_cast<Channel>(i), Input::DEFAULT);
}
- return true;
+ // We fail even if one channel didn't pass the test
+ return success;
}
ADS131M04Data ADS131M04::sampleImpl()
@@ -340,7 +404,7 @@ void ADS131M04::setChannelGainCalibrationImpl(Channel channel, double gain)
gain = 2;
}
- // The ADS131M04 corrects for gain errors by multiplying the ADC conversion
+ // The ADS131M08 corrects for gain errors by multiplying the ADC conversion
// result using the gain calibration registers.
// The contents of the gain calibration registers are interpreted by the
// dives as 24-bit unsigned values corresponding to linear steps from 0 to
diff --git a/src/shared/sensors/ADS131M04/ADS131M04.h b/src/shared/sensors/ADS131M04/ADS131M04.h
index 514034573..c5ac7068f 100644
--- a/src/shared/sensors/ADS131M04/ADS131M04.h
+++ b/src/shared/sensors/ADS131M04/ADS131M04.h
@@ -97,8 +97,24 @@ public:
*/
void calibrateOffset();
+ /**
+ * @brief changes the oversampling ratio.
+ *
+ * Keep in mind that after changing the oversampling ratio the device resets
+ * the internal digital filter and needs some time to settle.
+ * So if you immediately take a sample you'll read zeros.
+ *
+ * @warning This is especially important if you perform an offset
+ * calibration right after changing the oversampling ratio.
+ */
void setOversamplingRatio(ADS131M04Defs::OversamplingRatio ratio);
+ /**
+ * @brief Sets the channel programmable gain amplifier.
+ *
+ * The programmable gain amplifier allows the ADC to measure low level
+ * signals with the full resolution.
+ */
void setChannelPGA(ADS131M04Defs::Channel channel, ADS131M04Defs::PGA gain);
/**
@@ -111,15 +127,8 @@ public:
/**
* @brief Sets the channel gain calibration.
*
- * The ADS131M04 corrects for gain errors by multiplying the ADC conversion
- * result using the gain calibration registers.
- * The gain calibration value is interpreted as a 24bit unsigned. The values
- * corresponds to n * (1/2^23), ranging from 0 to 2 - (1/2^23).
- *
- * This function accepts a value between 0 and 2, it then compute the
- * correct gain register value.
- *
- * @param gain Must be between 0 and 2.
+ * @param gain Gain value between 0 and 2. Values outside this range will be
+ * capped.
*/
void setChannelGainCalibration(ADS131M04Defs::Channel channel, double gain);
@@ -127,10 +136,35 @@ public:
void disableChannel(ADS131M04Defs::Channel channel);
+ /**
+ * @brief Enables the global chop mode.
+ *
+ * When global chop mode is enabled the ADC uses the conversion results from
+ * two consecutive internal conversions taken with opposite input polarity
+ * to cancel the device internal offset voltage.
+ *
+ * The drawback of this mode is that the sampling rate is reduced. The
+ * conversion period is reduced because every time the device swaps the
+ * input polarity, the internal filter is reset. The ADC then always takes
+ * three internal conversions to produce one result.
+ *
+ * For more details see chapter 8.4.3.2 of the datasheet.
+ */
void enableGlobalChopMode();
+ /**
+ * @brief Disables the global chop mode.
+ *
+ * See enableGlobalChopMode() for more details on the global chop mode.
+ */
void disableGlobalChopMode();
+ /**
+ * @brief The self test samples internally connects each channel to known
+ * test signals and verifies if the sampled values are in an expected range.
+ *
+ * @returns True if the self test is successful, false otherwise.
+ */
bool selfTest() override;
private:
@@ -139,11 +173,23 @@ private:
void setChannelInput(ADS131M04Defs::Channel channel,
ADS131M04Defs::Input input);
+ /**
+ * setChannelPGS() implementation without saving the gain value in
+ * the local variable.
+ */
void setChannelPGAImpl(ADS131M04Defs::Channel channel,
ADS131M04Defs::PGA gain);
+ /**
+ * setChannelOffset() implementation without saving the offset value in
+ * the local variable.
+ */
void setChannelOffsetImpl(ADS131M04Defs::Channel channel, uint32_t offset);
+ /**
+ * setChannelGainCalibration() implementation without saving the gain value
+ * in the local variable.
+ */
void setChannelGainCalibrationImpl(ADS131M04Defs::Channel channel,
double gain);
@@ -162,6 +208,12 @@ private:
ADS131M04Defs::Register getChannelGainRegisterLSB(
ADS131M04Defs::Channel channel);
+ /**
+ * @brief Sends a NULL command, reads the channels samples and stores the
+ * values in the given array.
+ *
+ * @returns Returns true if the CRC is correct, false otherwise.
+ */
bool readSamples(int32_t rawValues[ADS131M04Defs::CHANNELS_NUM]);
uint16_t readRegister(ADS131M04Defs::Register reg);
@@ -174,11 +226,17 @@ private:
void sendCommand(SPITransaction& transaction, ADS131M04Defs::Command cmd,
uint8_t data[ADS131M04Defs::FULL_FRAME_SIZE]);
+ /**
+ * @brief Given a gain value returns the conversion value for a raw data
+ * sample.
+ */
float getLSBSizeFromGain(ADS131M04Defs::PGA gain);
SPISlave spiSlave;
- // Current channels configuration
+ // Saving the current configuration of the device
+ // This is necessary because the selfTest and calibrateOffset functions
+ // temporarily resets the channels configuration
ADS131M04Defs::PGA channelsPGAGain[ADS131M04Defs::CHANNELS_NUM];
uint32_t channelsOffset[ADS131M04Defs::CHANNELS_NUM];
double channelsGain[ADS131M04Defs::CHANNELS_NUM];
diff --git a/src/shared/sensors/ADS131M08/ADS131M08.cpp b/src/shared/sensors/ADS131M08/ADS131M08.cpp
index dfcda68ab..4dbff38b1 100644
--- a/src/shared/sensors/ADS131M08/ADS131M08.cpp
+++ b/src/shared/sensors/ADS131M08/ADS131M08.cpp
@@ -40,7 +40,7 @@ ADS131M08::ADS131M08(SPIBusInterface &bus, miosix::GpioPin cs,
ADS131M08::ADS131M08(SPISlave spiSlave) : spiSlave(spiSlave)
{
- // Initialize the channel configurations
+ // Initialize the channel configurations to the default values
for (int i = 0; i < CHANNELS_NUM; i++)
{
channelsPGAGain[i] = PGA::PGA_1;
@@ -87,7 +87,10 @@ bool ADS131M08::reset()
void ADS131M08::calibrateOffset()
{
- // Reset all offsets and gains, otherwise the calibration would be wrong
+ // The device internal data chain firsts subtracts the offset and then
+ // multiplies for the gain. To calibrate the offset we first reset it, then
+ // take some samples and apply the average as the new offset.
+ // So we need to reset the offset and gain
for (int i = 0; i < CHANNELS_NUM; i++)
{
setChannelOffsetImpl(static_cast<Channel>(i), 0);
@@ -117,17 +120,32 @@ void ADS131M08::calibrateOffset()
realSampleCount++;
}
- for (int i = 0; i < CHANNELS_NUM; i++)
- {
- // Compute the average
- averageValues[i] /= realSampleCount;
- LOG_INFO(logger, "Channel {} average offset: {}", i,
- averageValues[i] * getLSBSizeFromGain(channelsPGAGain[i]));
- // The new offset is the average value
- setChannelOffset(static_cast<Channel>(i), averageValues[i]);
+ if (realSampleCount == 0)
+ {
+ LOG_ERR(logger, "Calibration failed, no valid samples");
+ }
+ else
+ {
+ for (int i = 0; i < CHANNELS_NUM; i++)
+ {
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+ LOG_INFO(logger, "Channel {} average offset: {}", i,
+ averageValues[i] * getLSBSizeFromGain(channelsPGAGain[i]));
+
+ // Set the new offset only if valid, otherwise keep the old one
+ if (averageValues[i] != 0)
+ {
+ channelsOffset[i] = averageValues[i];
+ }
+ }
+ }
- // Reset the gain as it was before
+ // Update the offset values and reset the gain as it was before
+ for (int i = 0; i < CHANNELS_NUM; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), channelsOffset[i]);
setChannelGainCalibrationImpl(static_cast<Channel>(i), channelsGain[i]);
}
}
@@ -181,8 +199,7 @@ void ADS131M08::disableGlobalChopMode()
bool ADS131M08::selfTest()
{
- float voltage[CHANNELS_NUM] = {0};
- bool success = true;
+ bool success = true;
// Reset PGA, offsets and gains and connect the positive test signal
for (int i = 0; i < CHANNELS_NUM; i++)
@@ -194,31 +211,59 @@ bool ADS131M08::selfTest()
}
// Take some samples
+ int32_t averageValues[CHANNELS_NUM] = {0};
+ int realSampleCount = 0;
for (int i = 0; i < SELF_TEST_SAMPLES; i++)
{
+ // Wait for a sample to be ready
Thread::sleep(4);
- auto newSample = sampleImpl();
+
+ // Sample the channels
+ int32_t rawValues[CHANNELS_NUM];
+ if (!readSamples(rawValues))
+ {
+ // If the CRC failed we skip this sample
+ continue;
+ }
for (int j = 0; j < CHANNELS_NUM; j++)
{
- voltage[j] += newSample.voltage[j];
+ averageValues[j] += rawValues[j];
}
+
+ realSampleCount++;
}
- // Check the values
- for (int i = 0; i < CHANNELS_NUM; i++)
+ if (realSampleCount == 0)
{
- // Compute the average
- voltage[i] /= SELF_TEST_SAMPLES;
-
- // Check if the value is in the acceptable range
- if (voltage[i] < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ LOG_ERR(logger,
+ "Failed self test with positive DC signal, no valid samples");
+ success = false;
+ }
+ else
+ {
+ // Check the values
+ for (int i = 0; i < CHANNELS_NUM; i++)
{
- LOG_ERR(logger,
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+
+ // Convert the value to Volts
+ float volts = averageValues[i] * getLSBSizeFromGain(PGA::PGA_1);
+
+ // Check if the value is in the acceptable range
+ if (volts < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ {
+ LOG_ERR(
+ logger,
"Self test failed on channel {} on positive test signal, "
"value was {}",
- i, voltage[i]);
- success = false;
+ i, volts);
+ success = false;
+ }
+
+ // Reset the raw value
+ averageValues[i] = 0;
}
}
@@ -229,40 +274,58 @@ bool ADS131M08::selfTest()
}
// Take some samples
+ realSampleCount = 0;
for (int i = 0; i < SELF_TEST_SAMPLES; i++)
{
+ // Wait for a sample to be ready
Thread::sleep(4);
- auto newSample = sampleImpl();
+
+ // Sample the channels
+ int32_t rawValues[CHANNELS_NUM];
+ if (!readSamples(rawValues))
+ {
+ // If the CRC failed we skip this sample
+ continue;
+ }
for (int j = 0; j < CHANNELS_NUM; j++)
{
- voltage[j] += newSample.voltage[j];
+ averageValues[j] += rawValues[j];
}
+
+ realSampleCount++;
}
- // Check the values
- for (int i = 0; i < CHANNELS_NUM; i++)
+ if (realSampleCount == 0)
{
- // Compute the average
- voltage[i] /= SELF_TEST_SAMPLES;
-
- // Check if the value is in the acceptable range
- if (voltage[i] > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ LOG_ERR(logger,
+ "Failed self test with positive DC signal, no valid samples");
+ success = false;
+ }
+ else
+ {
+ // Check the values
+ for (int i = 0; i < CHANNELS_NUM; i++)
{
- LOG_ERR(logger,
+ // Compute the average
+ averageValues[i] /= realSampleCount;
+
+ // Convert the value to Volts
+ float volts = averageValues[i] * getLSBSizeFromGain(PGA::PGA_1);
+
+ // Check if the value is in the acceptable range
+ if (volts > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ {
+ LOG_ERR(
+ logger,
"Self test failed on channel {} on negative test signal, "
"value was {}",
- i, voltage[i]);
- success = false;
+ i, volts);
+ success = false;
+ }
}
}
- // If any channel failed we return false
- if (!success)
- {
- return false;
- }
-
// Reset channels previous configuration
for (int i = 0; i < CHANNELS_NUM; i++)
{
@@ -272,7 +335,8 @@ bool ADS131M08::selfTest()
setChannelInput(static_cast<Channel>(i), Input::DEFAULT);
}
- return true;
+ // We fail even if one channel didn't pass the test
+ return success;
}
ADS131M08Data ADS131M08::sampleImpl()
diff --git a/src/shared/sensors/ADS131M08/ADS131M08.h b/src/shared/sensors/ADS131M08/ADS131M08.h
index 705cf29dd..01ad2c733 100644
--- a/src/shared/sensors/ADS131M08/ADS131M08.h
+++ b/src/shared/sensors/ADS131M08/ADS131M08.h
@@ -97,8 +97,24 @@ public:
*/
void calibrateOffset();
+ /**
+ * @brief changes the oversampling ratio.
+ *
+ * Keep in mind that after changing the oversampling ratio the device resets
+ * the internal digital filter and needs some time to settle.
+ * So if you immediately take a sample you'll read zeros.
+ *
+ * @warning This is especially important if you perform an offset
+ * calibration right after changing the oversampling ratio.
+ */
void setOversamplingRatio(ADS131M08Defs::OversamplingRatio ratio);
+ /**
+ * @brief Sets the channel programmable gain amplifier.
+ *
+ * The programmable gain amplifier allows the ADC to measure low level
+ * signals with the full resolution.
+ */
void setChannelPGA(ADS131M08Defs::Channel channel, ADS131M08Defs::PGA gain);
/**
@@ -111,15 +127,8 @@ public:
/**
* @brief Sets the channel gain calibration.
*
- * The ADS131M08 corrects for gain errors by multiplying the ADC conversion
- * result using the gain calibration registers.
- * The gain calibration value is interpreted as a 24bit unsigned. The values
- * corresponds to n * (1/2^23), ranging from 0 to 2 - (1/2^23).
- *
- * This function accepts a value between 0 and 2, it then compute the
- * correct gain register value.
- *
- * @param gain Must be between 0 and 2.
+ * @param gain Gain value between 0 and 2. Values outside this range will be
+ * capped.
*/
void setChannelGainCalibration(ADS131M08Defs::Channel channel, double gain);
@@ -127,10 +136,35 @@ public:
void disableChannel(ADS131M08Defs::Channel channel);
+ /**
+ * @brief Enables the global chop mode.
+ *
+ * When global chop mode is enabled the ADC uses the conversion results from
+ * two consecutive internal conversions taken with opposite input polarity
+ * to cancel the device internal offset voltage.
+ *
+ * The drawback of this mode is that the sampling rate is reduced. The
+ * conversion period is reduced because every time the device swaps the
+ * input polarity, the internal filter is reset. The ADC then always takes
+ * three internal conversions to produce one result.
+ *
+ * For more details see chapter 8.4.3.2 of the datasheet.
+ */
void enableGlobalChopMode();
+ /**
+ * @brief Disables the global chop mode.
+ *
+ * See enableGlobalChopMode() for more details on the global chop mode.
+ */
void disableGlobalChopMode();
+ /**
+ * @brief The self test samples internally connects each channel to known
+ * test signals and verifies if the sampled values are in an expected range.
+ *
+ * @returns True if the self test is successful, false otherwise.
+ */
bool selfTest() override;
private:
@@ -139,11 +173,23 @@ private:
void setChannelInput(ADS131M08Defs::Channel channel,
ADS131M08Defs::Input input);
+ /**
+ * setChannelPGS() implementation without saving the gain value in
+ * the local variable.
+ */
void setChannelPGAImpl(ADS131M08Defs::Channel channel,
ADS131M08Defs::PGA gain);
+ /**
+ * setChannelOffset() implementation without saving the offset value in
+ * the local variable.
+ */
void setChannelOffsetImpl(ADS131M08Defs::Channel channel, uint32_t offset);
+ /**
+ * setChannelGainCalibration() implementation without saving the gain value
+ * in the local variable.
+ */
void setChannelGainCalibrationImpl(ADS131M08Defs::Channel channel,
double gain);
@@ -162,6 +208,12 @@ private:
ADS131M08Defs::Register getChannelGainRegisterLSB(
ADS131M08Defs::Channel channel);
+ /**
+ * @brief Sends a NULL command, reads the channels samples and stores the
+ * values in the given array.
+ *
+ * @returns Returns true if the CRC is correct, false otherwise.
+ */
bool readSamples(int32_t rawValues[ADS131M08Defs::CHANNELS_NUM]);
uint16_t readRegister(ADS131M08Defs::Register reg);
@@ -174,11 +226,17 @@ private:
void sendCommand(SPITransaction& transaction, ADS131M08Defs::Command cmd,
uint8_t data[ADS131M08Defs::FULL_FRAME_SIZE]);
+ /**
+ * @brief Given a gain value returns the conversion value for a raw data
+ * sample.
+ */
float getLSBSizeFromGain(ADS131M08Defs::PGA gain);
SPISlave spiSlave;
- // Current channels configuration
+ // Saving the current configuration of the device
+ // This is necessary because the selfTest and calibrateOffset functions
+ // temporarily resets the channels configuration
ADS131M08Defs::PGA channelsPGAGain[ADS131M08Defs::CHANNELS_NUM];
uint32_t channelsOffset[ADS131M08Defs::CHANNELS_NUM];
double channelsGain[ADS131M08Defs::CHANNELS_NUM];
diff --git a/src/tests/sensors/test-ads131m04.cpp b/src/tests/sensors/test-ads131m04.cpp
index 6c001ae8e..cda44e9bc 100644
--- a/src/tests/sensors/test-ads131m04.cpp
+++ b/src/tests/sensors/test-ads131m04.cpp
@@ -70,11 +70,11 @@ int main()
printf("Now performing self test...\n");
if (ads131.selfTest())
{
- printf("Self test failed!\n");
+ printf("Self test succeeded\n");
}
else
{
- printf("Self test succeeded\n");
+ printf("Self test failed!\n");
}
while (true)
diff --git a/src/tests/sensors/test-ads131m08.cpp b/src/tests/sensors/test-ads131m08.cpp
index 180ec04b5..ee199d39c 100644
--- a/src/tests/sensors/test-ads131m08.cpp
+++ b/src/tests/sensors/test-ads131m08.cpp
@@ -70,11 +70,11 @@ int main()
printf("Now performing self test...\n");
if (ads131.selfTest())
{
- printf("Self test failed!\n");
+ printf("Self test succeeded\n");
}
else
{
- printf("Self test succeeded\n");
+ printf("Self test failed!\n");
}
while (true)
--
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