From 8175eab76ababb7f9630f783660ed05d973df6df 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] Fixed offset calibration and implemented self test
---
src/shared/sensors/ADS131M04/ADS131M04.cpp | 162 +++++++++++++----
src/shared/sensors/ADS131M04/ADS131M04.h | 10 ++
src/shared/sensors/ADS131M08/ADS131M08.cpp | 200 +++++++++++++++------
src/shared/sensors/ADS131M08/ADS131M08.h | 10 ++
src/tests/sensors/test-ads131m08.cpp | 17 +-
5 files changed, 307 insertions(+), 92 deletions(-)
diff --git a/src/shared/sensors/ADS131M04/ADS131M04.cpp b/src/shared/sensors/ADS131M04/ADS131M04.cpp
index 3b7387c41..797d9ba46 100644
--- a/src/shared/sensors/ADS131M04/ADS131M04.cpp
+++ b/src/shared/sensors/ADS131M04/ADS131M04.cpp
@@ -26,6 +26,7 @@
#include <util/crc16.h>
#include <utils/CRC.h>
+using namespace miosix;
using namespace Boardcore::ADS131M04RegisterBitMasks;
namespace Boardcore
@@ -100,32 +101,47 @@ bool ADS131M04::reset()
void ADS131M04::calibrateOffset()
{
- int32_t averageValues[4] = {0};
+ // Reset all offsets and gains
+ for (int i = 0; i < 8; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), 0);
+ }
// Sample the channels and average the samples
- for (int i = 0; i < 1000; i++)
+ int32_t averageValues[4] = {0};
+ for (int i = 0; i < 250; i++)
{
- sample();
- miosix::delayUs(1);
+ Thread::sleep(4);
- for (int ii = 0; ii < 4; ii++)
- averageValues[ii] +=
- lastSample.voltage[ii] /
- PGA_LSB_SIZE[static_cast<uint16_t>(channelsPGAGain[ii])];
- }
+ uint8_t data[18] = {0};
+
+ data[0] = static_cast<uint16_t>(Commands::NULL_CMD) >> 8;
+ data[1] = static_cast<uint16_t>(Commands::NULL_CMD);
+
+ SPITransaction transaction(spiSlave);
+ transaction.transfer(data, sizeof(data));
+
+ for (int j = 0; j < 4; j++)
+ {
+ int32_t tmp = static_cast<uint32_t>(data[j * 3 + 3]) << 16 |
+ static_cast<uint32_t>(data[j * 3 + 4]) << 8 |
+ static_cast<uint32_t>(data[j * 3 + 5]);
+ // Check for the sign bit
+ if (tmp & 0x00800000)
+ tmp |= 0xFF000000; // Extend the sign bit
+
+ averageValues[j] += tmp;
+ }
+ }
for (int i = 0; i < 4; i++)
- averageValues[i] /= 1000;
+ averageValues[i] /= 250;
// Configure the offset registers
- writeRegister(Registers::REG_CH0_OCAL_MSB, averageValues[0] >> 8);
- writeRegister(Registers::REG_CH0_OCAL_LSB, averageValues[0] << 16);
- writeRegister(Registers::REG_CH1_OCAL_MSB, averageValues[1] >> 8);
- writeRegister(Registers::REG_CH1_OCAL_LSB, averageValues[1] << 16);
- writeRegister(Registers::REG_CH2_OCAL_MSB, averageValues[2] >> 8);
- writeRegister(Registers::REG_CH2_OCAL_LSB, averageValues[2] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[3] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[3] << 16);
+ for (int i = 0; i < 4; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), averageValues[i]);
+ }
}
void ADS131M04::setChannelPGA(Channel channel, PGA gain)
@@ -162,8 +178,8 @@ void ADS131M04::setChannelOffset(Channel channel, uint32_t offset)
break;
}
- writeRegister(regMSB, static_cast<uint16_t>(offset) >> 16);
- writeRegister(regLSB, static_cast<uint16_t>(offset) << 8);
+ writeRegister(regMSB, offset >> 8);
+ writeRegister(regLSB, offset << 16);
}
void ADS131M04::setChannelGainCalibration(Channel channel, double gain)
@@ -201,6 +217,32 @@ void ADS131M04::setChannelGainCalibration(Channel channel, double gain)
writeRegister(regLSB, rawGain << 8);
}
+void ADS131M04::setChannelInput(Channel channel, Input input)
+{
+ // Set the correct register based on the selected channel
+ Registers reg;
+ switch (static_cast<int>(channel))
+ {
+ case 0:
+ reg = Registers::REG_CH0_CFG;
+ break;
+ case 1:
+ reg = Registers::REG_CH1_CFG;
+ break;
+ case 2:
+ reg = Registers::REG_CH2_CFG;
+ break;
+ default:
+ reg = Registers::REG_CH3_CFG;
+ break;
+ }
+
+ uint16_t value = readRegister(reg);
+ value &= REG_CHx_CFG_MUX;
+ value |= static_cast<uint16_t>(input);
+ writeRegister(reg, value);
+}
+
void ADS131M04::enableChannel(Channel channel)
{
changeRegister(Registers::REG_CLOCK, 1 << (static_cast<int>(channel) + 8),
@@ -233,7 +275,65 @@ ADCData ADS131M04::getVoltage(Channel channel)
bool ADS131M04::selfTest()
{
- // TODO
+ static constexpr float V_REF = 1.2;
+ static constexpr float TEST_SIGNAL_FACTOR = 2 / 15;
+ static constexpr float TEST_SIGNAL_SLACK = 0.1; // Not defined in DS
+
+ float voltage[4] = {0};
+
+ // Connect all channels to the positive DC test signal
+ for (int i = 0; i < 4; i++)
+ {
+ setChannelInput(static_cast<Channel>(i), Input::POSITIVE_DC_TEST);
+ setChannelPGA(static_cast<Channel>(i), PGA::PGA_1);
+ }
+
+ // Take some samples
+ for (int i = 0; i < 100; i++)
+ {
+ Thread::sleep(4);
+ auto newSample = sampleImpl();
+
+ for (int j = 0; j < 4; j++)
+ {
+ voltage[j] += newSample.voltage[j];
+ }
+ }
+
+ // Check values
+ for (int i = 0; i < 4; i++)
+ {
+ voltage[i] /= 100;
+ if (voltage[i] < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ return false;
+ }
+
+ // Connect all channels to the negative DC test signal
+ for (int i = 0; i < 4; i++)
+ {
+ setChannelInput(static_cast<Channel>(i), Input::NEGATIVE_DC_TEST);
+ }
+
+ // Take some samples
+ for (int i = 0; i < 100; i++)
+ {
+ Thread::sleep(4);
+ auto newSample = sampleImpl();
+
+ for (int j = 0; j < 4; j++)
+ {
+ voltage[j] += newSample.voltage[j];
+ }
+ }
+
+ // Check values
+ for (int i = 0; i < 4; i++)
+ {
+ voltage[i] /= 100;
+ if (voltage[i] > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ return false;
+ }
+
return true;
}
@@ -250,18 +350,12 @@ ADS131M04Data ADS131M04::sampleImpl()
// Extract each channel value
int32_t rawValue[4];
- rawValue[0] = static_cast<uint32_t>(data[3]) << 16 |
- static_cast<uint32_t>(data[4]) << 8 |
- static_cast<uint32_t>(data[5]);
- rawValue[1] = static_cast<uint32_t>(data[6]) << 16 |
- static_cast<uint32_t>(data[7]) << 8 |
- static_cast<uint32_t>(data[8]);
- rawValue[2] = static_cast<uint32_t>(data[9]) << 16 |
- static_cast<uint32_t>(data[10]) << 8 |
- static_cast<uint32_t>(data[11]);
- rawValue[3] = static_cast<uint32_t>(data[12]) << 16 |
- static_cast<uint32_t>(data[13]) << 8 |
- static_cast<uint32_t>(data[14]);
+ for (int i = 0; i < 4; i++)
+ {
+ rawValue[i] = static_cast<uint32_t>(data[i * 3 + 3]) << 16 |
+ static_cast<uint32_t>(data[i * 3 + 4]) << 8 |
+ static_cast<uint32_t>(data[i * 3 + 5]);
+ }
// Extract and verify the CRC
uint16_t dataCrc =
@@ -281,7 +375,7 @@ ADS131M04Data ADS131M04::sampleImpl()
for (int i = 0; i < 4; i++)
{
// Check for the sign bit
- if (rawValue[i] & 0x800000)
+ if (rawValue[i] & 0x00800000)
rawValue[i] |= 0xFF000000; // Extend the sign bit
}
diff --git a/src/shared/sensors/ADS131M04/ADS131M04.h b/src/shared/sensors/ADS131M04/ADS131M04.h
index 9d948a288..c2857a4f8 100644
--- a/src/shared/sensors/ADS131M04/ADS131M04.h
+++ b/src/shared/sensors/ADS131M04/ADS131M04.h
@@ -116,6 +116,14 @@ public:
CHANNEL_3 = 3
};
+ enum class Input : uint8_t
+ {
+ DEFAULT = 0, // AINxP and AINxN (default)
+ SHORTED = 1, // ADC inputs shorted
+ POSITIVE_DC_TEST = 2, // Positive DC test signal
+ NEGATIVE_DC_TEST = 3 // Negative DC test signal
+ };
+
ADS131M04(SPIBusInterface &bus, miosix::GpioPin cs,
SPIBusConfig config = getDefaultSPIConfig());
@@ -164,6 +172,8 @@ public:
*/
void setChannelGainCalibration(Channel channel, double gain);
+ void setChannelInput(Channel channel, Input input);
+
void enableChannel(Channel channel);
void disableChannel(Channel channel);
diff --git a/src/shared/sensors/ADS131M08/ADS131M08.cpp b/src/shared/sensors/ADS131M08/ADS131M08.cpp
index 9ea5204cc..21c30d1e3 100644
--- a/src/shared/sensors/ADS131M08/ADS131M08.cpp
+++ b/src/shared/sensors/ADS131M08/ADS131M08.cpp
@@ -26,6 +26,7 @@
#include <util/crc16.h>
#include <utils/CRC.h>
+using namespace miosix;
using namespace Boardcore::ADS131M08RegisterBitMasks;
namespace Boardcore
@@ -79,7 +80,7 @@ bool ADS131M08::init()
bool ADS131M08::reset()
{
// Write all the communication frame which is maximum 6 24bit words
- uint8_t data[18] = {0};
+ uint8_t data[30] = {0};
// Prepare the command
data[1] = static_cast<uint16_t>(Commands::RESET);
@@ -92,7 +93,7 @@ bool ADS131M08::reset()
uint16_t response = data[0] << 8 | data[1];
// Check for the correct response
- if (response != 0xFF24)
+ if (response != 0xFF28)
{
lastError = SensorErrors::COMMAND_FAILED;
LOG_ERR(logger, "Reset command failed, response was {:X}", response);
@@ -104,40 +105,47 @@ bool ADS131M08::reset()
void ADS131M08::calibrateOffset()
{
- int32_t averageValues[8] = {0};
+ // Reset all offsets and gains
+ for (int i = 0; i < 8; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), 0);
+ }
// Sample the channels and average the samples
- for (int i = 0; i < 1000; i++)
+ int32_t averageValues[8] = {0};
+ for (int i = 0; i < 250; i++)
{
- sample();
- miosix::delayUs(1);
+ Thread::sleep(4);
- for (int ii = 0; ii < 4; ii++)
- averageValues[ii] +=
- lastSample.voltage[ii] /
- PGA_LSB_SIZE[static_cast<uint16_t>(channelsPGAGain[ii])];
- }
+ uint8_t data[30] = {0};
+
+ data[0] = static_cast<uint16_t>(Commands::NULL_CMD) >> 8;
+ data[1] = static_cast<uint16_t>(Commands::NULL_CMD);
+
+ SPITransaction transaction(spiSlave);
+ transaction.transfer(data, sizeof(data));
- for (int i = 0; i < 4; i++)
- averageValues[i] /= 1000;
+ for (int j = 0; j < 8; j++)
+ {
+ int32_t tmp = static_cast<uint32_t>(data[j * 3 + 3]) << 16 |
+ static_cast<uint32_t>(data[j * 3 + 4]) << 8 |
+ static_cast<uint32_t>(data[j * 3 + 5]);
+
+ // Check for the sign bit
+ if (tmp & 0x00800000)
+ tmp |= 0xFF000000; // Extend the sign bit
+
+ averageValues[j] += tmp;
+ }
+ }
+ for (int i = 0; i < 8; i++)
+ averageValues[i] /= 250;
// Configure the offset registers
- writeRegister(Registers::REG_CH0_OCAL_MSB, averageValues[0] >> 8);
- writeRegister(Registers::REG_CH0_OCAL_LSB, averageValues[0] << 16);
- writeRegister(Registers::REG_CH1_OCAL_MSB, averageValues[1] >> 8);
- writeRegister(Registers::REG_CH1_OCAL_LSB, averageValues[1] << 16);
- writeRegister(Registers::REG_CH2_OCAL_MSB, averageValues[2] >> 8);
- writeRegister(Registers::REG_CH2_OCAL_LSB, averageValues[2] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[3] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[3] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[4] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[4] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[5] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[5] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[6] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[6] << 16);
- writeRegister(Registers::REG_CH3_OCAL_MSB, averageValues[7] >> 8);
- writeRegister(Registers::REG_CH3_OCAL_LSB, averageValues[7] << 16);
+ for (int i = 0; i < 8; i++)
+ {
+ setChannelOffset(static_cast<Channel>(i), averageValues[i]);
+ }
}
void ADS131M08::setChannelPGA(Channel channel, PGA gain)
@@ -200,8 +208,8 @@ void ADS131M08::setChannelOffset(Channel channel, uint32_t offset)
break;
}
- writeRegister(regMSB, static_cast<uint16_t>(offset) >> 16);
- writeRegister(regLSB, static_cast<uint16_t>(offset) << 8);
+ writeRegister(regMSB, offset >> 8);
+ writeRegister(regLSB, offset << 16);
}
void ADS131M08::setChannelGainCalibration(Channel channel, double gain)
@@ -255,6 +263,44 @@ void ADS131M08::setChannelGainCalibration(Channel channel, double gain)
writeRegister(regLSB, rawGain << 8);
}
+void ADS131M08::setChannelInput(Channel channel, Input input)
+{
+ // Set the correct register based on the selected channel
+ Registers reg;
+ switch (static_cast<int>(channel))
+ {
+ case 0:
+ reg = Registers::REG_CH0_CFG;
+ break;
+ case 1:
+ reg = Registers::REG_CH1_CFG;
+ break;
+ case 2:
+ reg = Registers::REG_CH2_CFG;
+ break;
+ case 3:
+ reg = Registers::REG_CH3_CFG;
+ break;
+ case 4:
+ reg = Registers::REG_CH4_CFG;
+ break;
+ case 5:
+ reg = Registers::REG_CH5_CFG;
+ break;
+ case 6:
+ reg = Registers::REG_CH6_CFG;
+ break;
+ default:
+ reg = Registers::REG_CH7_CFG;
+ break;
+ }
+
+ uint16_t value = readRegister(reg);
+ value &= REG_CHx_CFG_MUX;
+ value |= static_cast<uint16_t>(input);
+ writeRegister(reg, value);
+}
+
void ADS131M08::enableChannel(Channel channel)
{
changeRegister(Registers::REG_CLOCK, 1 << (static_cast<int>(channel) + 8),
@@ -287,7 +333,65 @@ ADCData ADS131M08::getVoltage(Channel channel)
bool ADS131M08::selfTest()
{
- // TODO
+ static constexpr float V_REF = 1.2;
+ static constexpr float TEST_SIGNAL_FACTOR = 2 / 15;
+ static constexpr float TEST_SIGNAL_SLACK = 0.1; // Not defined in DS
+
+ float voltage[8] = {0};
+
+ // Connect all channels to the positive DC test signal
+ for (int i = 0; i < 8; i++)
+ {
+ setChannelInput(static_cast<Channel>(i), Input::POSITIVE_DC_TEST);
+ setChannelPGA(static_cast<Channel>(i), PGA::PGA_1);
+ }
+
+ // Take some samples
+ for (int i = 0; i < 100; i++)
+ {
+ Thread::sleep(4);
+ auto newSample = sampleImpl();
+
+ for (int j = 0; j < 8; j++)
+ {
+ voltage[j] += newSample.voltage[j];
+ }
+ }
+
+ // Check values
+ for (int i = 0; i < 8; i++)
+ {
+ voltage[i] /= 100;
+ if (voltage[i] < V_REF * TEST_SIGNAL_FACTOR - TEST_SIGNAL_SLACK)
+ return false;
+ }
+
+ // Connect all channels to the negative DC test signal
+ for (int i = 0; i < 8; i++)
+ {
+ setChannelInput(static_cast<Channel>(i), Input::NEGATIVE_DC_TEST);
+ }
+
+ // Take some samples
+ for (int i = 0; i < 100; i++)
+ {
+ Thread::sleep(4);
+ auto newSample = sampleImpl();
+
+ for (int j = 0; j < 8; j++)
+ {
+ voltage[j] += newSample.voltage[j];
+ }
+ }
+
+ // Check values
+ for (int i = 0; i < 8; i++)
+ {
+ voltage[i] /= 100;
+ if (voltage[i] > -V_REF * TEST_SIGNAL_FACTOR + TEST_SIGNAL_SLACK)
+ return false;
+ }
+
return true;
}
@@ -304,30 +408,12 @@ ADS131M08Data ADS131M08::sampleImpl()
// Extract each channel value
int32_t rawValue[8];
- rawValue[0] = static_cast<uint32_t>(data[3]) << 16 |
- static_cast<uint32_t>(data[4]) << 8 |
- static_cast<uint32_t>(data[5]);
- rawValue[1] = static_cast<uint32_t>(data[6]) << 16 |
- static_cast<uint32_t>(data[7]) << 8 |
- static_cast<uint32_t>(data[8]);
- rawValue[2] = static_cast<uint32_t>(data[9]) << 16 |
- static_cast<uint32_t>(data[10]) << 8 |
- static_cast<uint32_t>(data[11]);
- rawValue[3] = static_cast<uint32_t>(data[12]) << 16 |
- static_cast<uint32_t>(data[13]) << 8 |
- static_cast<uint32_t>(data[14]);
- rawValue[4] = static_cast<uint32_t>(data[15]) << 16 |
- static_cast<uint32_t>(data[16]) << 8 |
- static_cast<uint32_t>(data[17]);
- rawValue[5] = static_cast<uint32_t>(data[18]) << 16 |
- static_cast<uint32_t>(data[19]) << 8 |
- static_cast<uint32_t>(data[20]);
- rawValue[6] = static_cast<uint32_t>(data[21]) << 16 |
- static_cast<uint32_t>(data[22]) << 8 |
- static_cast<uint32_t>(data[23]);
- rawValue[7] = static_cast<uint32_t>(data[24]) << 16 |
- static_cast<uint32_t>(data[25]) << 8 |
- static_cast<uint32_t>(data[26]);
+ for (int i = 0; i < 8; i++)
+ {
+ rawValue[i] = static_cast<uint32_t>(data[i * 3 + 3]) << 16 |
+ static_cast<uint32_t>(data[i * 3 + 4]) << 8 |
+ static_cast<uint32_t>(data[i * 3 + 5]);
+ }
// Extract and verify the CRC
uint16_t dataCrc =
@@ -347,7 +433,7 @@ ADS131M08Data ADS131M08::sampleImpl()
for (int i = 0; i < 8; i++)
{
// Check for the sign bit
- if (rawValue[i] & 0x800000)
+ if (rawValue[i] & 0x00800000)
rawValue[i] |= 0xFF000000; // Extend the sign bit
}
diff --git a/src/shared/sensors/ADS131M08/ADS131M08.h b/src/shared/sensors/ADS131M08/ADS131M08.h
index 0d2d3c733..6dca0801f 100644
--- a/src/shared/sensors/ADS131M08/ADS131M08.h
+++ b/src/shared/sensors/ADS131M08/ADS131M08.h
@@ -120,6 +120,14 @@ public:
CHANNEL_7 = 3
};
+ enum class Input : uint8_t
+ {
+ DEFAULT = 0, // AINxP and AINxN (default)
+ SHORTED = 1, // ADC inputs shorted
+ POSITIVE_DC_TEST = 2, // Positive DC test signal
+ NEGATIVE_DC_TEST = 3 // Negative DC test signal
+ };
+
ADS131M08(SPIBusInterface &bus, miosix::GpioPin cs,
SPIBusConfig config = getDefaultSPIConfig());
@@ -168,6 +176,8 @@ public:
*/
void setChannelGainCalibration(Channel channel, double gain);
+ void setChannelInput(Channel channel, Input input);
+
void enableChannel(Channel channel);
void disableChannel(Channel channel);
diff --git a/src/tests/sensors/test-ads131m08.cpp b/src/tests/sensors/test-ads131m08.cpp
index 5deb400da..cd4dd482d 100644
--- a/src/tests/sensors/test-ads131m08.cpp
+++ b/src/tests/sensors/test-ads131m08.cpp
@@ -59,7 +59,22 @@ int main()
ADS131M08 ads131(spiSlave);
// Initialize the device
- ads131.init();
+ if (!ads131.init())
+ {
+ printf("Initialization failed!\n");
+ }
+ else
+ {
+ printf("Initialization done\n");
+ }
+ if (!ads131.selfTest())
+ {
+ printf("Self test failed!\n");
+ }
+ else
+ {
+ printf("Self test done\n");
+ }
ads131.enableGlobalChopMode();
ads131.setOversamplingRatio(ADS131M08::OversamplingRatio::OSR_16256);
ads131.calibrateOffset();
--
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