ESH10000121 - MPIO-I2C Module

Overview

The ESH10000121 is a multi-purpose I/O module providing 96 bidirectional analog/digital channels with I²C-based control, similar to ESH10000568 but using I²C communication instead of SPI for lower pin count requirements.

Description

The MPIO-I2C module provides 96 configurable I/O channels organized into 12 groups of 8 channels each, utilizing Analog Devices AD5593R multi-function I/O chips. Each channel can be independently configured as analog input, analog output, or pseudo-digital I/O with voltage threshold interpretation. The module is ideal for mixed-signal applications requiring both analog and digital interfacing capabilities.

Key Features:

• 96 Bidirectional Channels: Configurable as analog or pseudo-digital I/O

  • 12-bit ADC resolution (2x range mode, 0-5V typical)
  • 12-bit DAC resolution (2x range mode, 0-5V typical)
  • Pseudo-digital mode with programmable VL/VH thresholds
  • Support for open-drain and floating output emulation

• I²C Communication: Lower pin count compared to SPI

  • 400 kHz I²C bus speed
  • Reduced wiring complexity
  • Simpler hardware interfacing

• Flexible Configuration: Per-channel direction control

  • Bidirectional capability (IN | OUT)
  • Default direction: IN
  • Runtime direction switching for pseudo-digital outputs

• High-Speed Acquisition: Numeric result support

  • Multi-channel synchronized sampling
  • Configurable sample rates
  • Optional data reduction (min/max/avg/stddev)
  • Base64-encoded data transfer

• Per-Channel Calibration: Gain and offset adjustment

  • Independent calibration per channel
  • Analog mode: Configurable gain and offset
  • Pseudo-digital mode: VL/VH threshold configuration

Hardware Details

Multi-Function I/O:

• Chip: Analog Devices AD5593R (12 chips)
• Channels per chip: 8
• Total channels: 96
• Resolution: 12-bit ADC/DAC
• I²C Address: 0x11 (per chip, selected via GPIO)
• Communication: I²C bus @ 400 kHz
• Voltage Range: 0-5V (2x range mode enabled)
• Features:
  • Double ADC range mode: Enabled
  • Double DAC range mode: Enabled
  • Temperature sensor: Disabled (ReadTemperature = false)

GPIO Expander:

• Chip: NXP PI4IOE5V6416
• I²C Address: 0x20
• Purpose: Chip select addressing (A0-A11) and LED control
• Function: Routes active chip by setting address lines

Channel Naming Convention

All channels follow the naming pattern: {ModuleIndex}.ESH10000121.{ChannelName}

Where:

• {ModuleIndex} is the position of the module in the system (e.g., 0, 1, 2...)
• ESH10000121 is the module type identifier
• {ChannelName} is the specific channel name from the table below

Example: Module at position 0, channel 42 would be: 0.ESH10000121.MPIO42

User-Accessible Channels

Total User Channels: 98 (96 MPIO + NumericResult + CALIBRATION)

Note: Each MPIO channel supports dual capability (ChannelTypeCapability = Analog | PseudoDigital), allowing runtime conversion between analog and pseudo-digital modes.

Channel Configuration

Analog Mode

Channels operate as analog voltage measurement (input) or generation (output) with configurable parameters:

• Gain: Multiplicative calibration factor (default: 1.0)
• Offset: Additive calibration offset (default: 0.0)
• Resolution: Measurement resolution (12-bit fixed for AD5593R)
• Value: Measured or output voltage (0-5V typical)
• Direction: IN or OUT

Configuration Example:

ConfigureChannels(new[] {
    new AnalogChannel {
        NetName = "0.ESH10000121.MPIO00",
        Enabled = true,
        Direction = DirectionTypes.IN,
        Gain = 1.0,
        Offset = 0.0,
        Value = 0.0
    }
});

Pseudo-Digital Mode

Analog channels can be configured as digital I/O with voltage threshold interpretation:

• VL (Voltage Low): Maximum voltage considered logic LOW (default: 0.5V)
• VH (Voltage High): Minimum voltage considered logic HIGH (default: 1.5V)
• MinIoVoltage: Minimum allowable voltage (0V)
• MaxIoVoltage: Maximum allowable voltage (5V)
• Value: Boolean state (true/false)
• RawValue: Underlying analog voltage (read-only for inputs)

Constraints:

• VL >= MinIoVoltage (typically 0V)
• VL <= MaxIoVoltage (typically 5V)
• VH > VL (high threshold must exceed low threshold)
• Hysteresis: Values between VL and VH retain previous state

Configuration Example:

ConfigureChannels(new[] {
    new PseudoDigitalChannel {
        NetName = "0.ESH10000121.MPIO01",
        Enabled = true,
        Direction = DirectionTypes.IN,
        VL = 0.8,   // Logic LOW threshold
        VH = 2.0,   // Logic HIGH threshold
        MinIoVoltage = 0.0,
        MaxIoVoltage = 5.0
    }
});

Special Output Modes

Open-Drain Emulation: Set VH < 0 to enable open-drain mode:

• Logic HIGH: Channel set to INPUT (high-impedance state)
• Logic LOW: Channel drives VL voltage

new PseudoDigitalChannel {
    NetName = "0.ESH10000121.MPIO02",
    Direction = DirectionTypes.OUT,
    VL = 0.0,
    VH = -1.0,  // Negative VH enables open-drain
    Value = true  // Will set to INPUT (high-Z)
}

Float Emulation: Set VL < 0 to enable float mode:

• Logic LOW: Channel set to INPUT (high-impedance state)
• Logic HIGH: Channel drives VH voltage

new PseudoDigitalChannel {
    NetName = "0.ESH10000121.MPIO03",
    Direction = DirectionTypes.OUT,
    VL = -1.0,  // Negative VL enables float
    VH = 3.3,
    Value = false  // Will set to INPUT (high-Z)
}

Numeric Result Mode

High-speed data acquisition mode for capturing multiple samples:

• NumberOfSamples: Number of samples to acquire
• SampleRate: Acquisition rate (samples per second)
• TargetNetName: Comma-separated list of channels to acquire
• ReducedSet: Enable statistical data reduction (min/max/avg/stddev)
• MultiChannel: Enable multi-channel synchronized acquisition
• Base64String: Acquired data encoded as Base64 (output)
• PossibleTargetNames: Array of valid analog channel names for targeting

Configuration Example:

ConfigureChannels(new[] {
    new NumericResultChannel {
        NetName = "0.ESH10000121.NumericResult",
        Enabled = true,
        NumberOfSamples = 1000,
        SampleRate = 10000,  // 10 kHz
        TargetNetName = "0.ESH10000121.MPIO00,0.ESH10000121.MPIO01",
        ReducedSet = false,
        MultiChannel = true
    }
});

// Read acquired data
string[] result = GetValues(new[] { "0.ESH10000121.NumericResult" });
List<NumericResult> data = NumericResult.FromBase64(result[0]);

Internal Channels (Not User-Accessible)

The following channels are used for internal system control and are hidden from users:

• GPIO Expander Signals (all HiddenSystemControl):
  • RESET: Global reset control for all AD5593R chips
  • A0-A11: Chip select address lines (12 chips)
  • LED_STATUS_R/G/B: Status LED control

Data Bus Integration

The module provides a data bus with 96 signals (12 groups × 8 signals):

• Signal Type: Analog
• NetName Pattern: {ModuleIndex}.ESH10000121.MPIO{00-95}
• Purpose: Internal signal routing and cross-module connectivity
• Note: MPIO signals can be used for module-to-module connections via data bus

Programming Interface

Configure Analog Input:

ConfigureChannels(new[] {
    new AnalogChannel {
        NetName = "0.ESH10000121.MPIO00",
        Enabled = true,
        Direction = DirectionTypes.IN,
        Gain = 2.0,      // Apply 2x gain
        Offset = -0.5,   // Subtract 0.5V offset
        Resolution = 12
    }
});

Configure Analog Output:

ConfigureChannels(new[] {
    new AnalogChannel {
        NetName = "0.ESH10000121.MPIO10",
        Enabled = true,
        Direction = DirectionTypes.OUT,
        Value = 2.5      // Output 2.5V
    }
});

Configure Pseudo-Digital Input:

ConfigureChannels(new[] {
    new PseudoDigitalChannel {
        NetName = "0.ESH10000121.MPIO20",
        Enabled = true,
        Direction = DirectionTypes.IN,
        VL = 0.8,   // 0V-0.8V = LOW
        VH = 2.0    // 2.0V-5V = HIGH
    }
});

Read Multiple Channels:

string[] values = GetValues(new[] {
    "0.ESH10000121.MPIO00",
    "0.ESH10000121.MPIO01",
    "0.ESH10000121.MPIO20"
});
// values[0] = "2.345" (analog voltage)
// values[1] = "1.234" (analog voltage)
// values[2] = "true" (pseudo-digital state)

Set Output Values:

SetValues(
    new[] {
        "0.ESH10000121.MPIO10",  // Analog output
        "0.ESH10000121.MPIO11"   // Pseudo-digital output
    },
    new[] {
        "3.3",    // 3.3V
        "true"    // Logic HIGH (will output VH voltage)
    }
);

Multi-Channel Acquisition:

// Step 1: Configure numeric result channel
ConfigureChannels(new[] {
    new NumericResultChannel {
        NetName = "0.ESH10000121.NumericResult",
        Enabled = true,
        NumberOfSamples = 500,
        SampleRate = 5000,  // 5 kHz
        TargetNetName = "0.ESH10000121.MPIO00,0.ESH10000121.MPIO01,0.ESH10000121.MPIO02",
        ReducedSet = true,  // Get min/max/avg/stddev
        MultiChannel = true
    }
});

// Step 2: Read results
string[] result = GetValues(new[] { "0.ESH10000121.NumericResult" });
List<NumericResult> data = NumericResult.FromBase64(result[0]);

// Step 3: Process results
foreach (var channel in data)
{
    Console.WriteLine($"{channel.NetName}:");
    Console.WriteLine($"  Min: {channel.Min}");
    Console.WriteLine($"  Max: {channel.Max}");
    Console.WriteLine($"  Avg: {channel.Average}");
    Console.WriteLine($"  StdDev: {channel.StdDev}");
}

Error Handling

The module validates channel configuration and provides detailed error messages:

• Invalid NetName: Throws exception if channel does not exist
• Invalid VL: Validates VL is within MinIoVoltage-MaxIoVoltage range
• Invalid VH: Validates VH exceeds VL
• Direction Mismatch: Prevents output operations on input channels and vice versa
• Disabled Channel Operations: Allows GetValue on disabled channels, skips SetValue for disabled outputs
• Target Channel Validation: Validates numeric result target channels exist and are analog type

Best Practices

1. Always configure direction before use: Specify IN or OUT explicitly in ConfigureChannels
2. Enable channels before operations: Set Enabled = true for all active channels
3. Use appropriate mode for application:
   • Analog mode: Precision voltage measurements/generation
   • Pseudo-digital mode: Simple digital I/O with voltage flexibility
4. Configure VL/VH with margin: Leave hysteresis gap (typically 0.5-1.0V) to avoid oscillation
5. Batch operations: Use multi-channel GetValues/SetValues for better performance
6. I²C bus speed: Module configured for 400 kHz I²C (faster than standard 100 kHz)
7. Chip select handling: Module automatically manages chip addressing via GPIO expander
8. Open-drain/float modes: Use negative VH/VL for special output modes (wired-OR, tri-state)
9. Numeric results for high-speed: Use NumericResultChannel for acquisition > 100 samples
10. Monitor I²C bus errors: Chip select logic includes retry mechanism (up to 10 retries)

Module Initialization Sequence

On Reset(), the module performs the following initialization:

1. Clear existing channel list
2. Setup GPIO expander (PI4IOE5V6416) with chip select signals (A0-A11)
3. Reset GPIO expander to default state
4. Generate 96 MPIO channels (MPIO00-MPIO95):
   • Create 12 groups of 8 channels (CHIP00-CHIP11)
   • Initialize each channel as bidirectional analog/pseudo-digital
   • Set default direction to IN
   • Enable dual capability (Analog | PseudoDigital)
5. Create 12 AD5593R device instances:
   • Configure I²C address (0x11)
   • Enable double ADC range mode (0-5V)
   • Enable double DAC range mode (0-5V)
   • Disable temperature sensor reading
   • Set I²C clock to 400 kHz
6. Reset all 12 AD5593R chips
7. Add NumericResult channel with possible target names populated
8. Add CALIBRATION channel (implicit, inherited from base Module class)

Chip Select Mechanism

The module uses a GPIO expander to route I²C communication to individual AD5593R chips:

• Address Lines A0-A11: Select active chip (one-hot encoding)
• Automatic Switching: EnableChannel() sets appropriate chip select
• Retry Logic: Up to 10 retries on I²C communication failure
• Source Bus Pattern: MAIN.CHIP{00-11} identifies target chip

Example Chip Select Operation:

// When accessing MPIO00-MPIO07 (CHIP00):
// - Sets A0=true, A1-A11=false
// - Enables I²C communication to AD5593R #0 at address 0x11

// When accessing MPIO08-MPIO15 (CHIP01):
// - Sets A1=true, A0,A2-A11=false
// - Enables I²C communication to AD5593R #1 at address 0x11

Comparison with ESH10000568

Revision History

• ESH10000121: Current production version
  • 96 MPIO channels (AD5593R × 12)
  • I²C communication @ 400 kHz
  • Dual capability (Analog | PseudoDigital)
  • Numeric results support
  • Open-drain and float emulation