AD7606p16_t4

High-speed 16-bit parallel AD7606 ADC library for Teensy 4.x

Features

🚀 Ultra-High Performance: 200 kSPS per second
⚡ Optimized GPIO Access: Direct port register reading 🎯 Teensy 4.x Optimized: Leverages GPIO6, GPIO7 & GPIO8 fast ports
📊 8-Channel Simultaneous: All 8 AD7606 channels read in parallel
🔧 Easy Integration: Drop-in replacement for slower bit-banging approaches

Performance Comparison

Method	Speed	CPU Usage
Individual digitalRead()	~1K/sec	High (lockups)
AD7606p16_t4	200 kSPS	Minimal

Hardware Requirements

• Teensy 4.1, or MicroMod (4.0 might work if you can somehow access all the pins, but I dobut it)
• AD7606 ADC in 16-bit parallel mode
• 16 data pins + 5 control pins

Quick Start

Installation

PlatformIO:

[env:teensy41]
lib_deps = 
    https://github.com/yourusername/AD7606p16_t4.git

Arduino IDE:

• Download library ZIP from GitHub
• Sketch → Include Library → Add .ZIP Library

Basic Usage

#include <AD7606p16_t4.h>

// Default constructor (10V reference for ±5V range)
AD7606p16_t4 adc(RD_PIN, CS_PIN, CONV_PIN, BUSY_PIN, RESET_PIN);

// Custom reference voltage (20V for ±10V range)
// AD7606p16_t4 adc(RD_PIN, CS_PIN, CONV_PIN, BUSY_PIN, RESET_PIN, 20.0f);

int16_t channels[8];
float voltages[8];

void loop() {
    adc.getData(channels);      // Get raw 16-bit readings
    adc.getVoltages(voltages);  // Get all voltages at once
    
    float ch0_voltage = adc.getVoltage(0);  // Get single channel voltage
}

Pin Configuration

The library uses optimized GPIO port mapping for maximum speed:

Data Pins (D0-D15)

Data Pin	Teensy4.1 Pin	Teensy4.1 GPIO	TeensyMM Pin	TeensyMM GPIO
D0	19	GPIO6.16	37	GPIO8.12
D1	18	GPIO6.17	36	GPIO8.13
D2	14	GPIO6.18	35	GPIO8.14
D3	15	GPIO6.19	34	GPIO8.15
D4	40	GPIO6.20	38	GPIO8.16
D5	41	GPIO6.21	39	GPIO8.17
D6	17	GPIO6.22	40	GPIO7.4
D7	16	GPIO6.23	41	GPIO7.5
D8	22	GPIO6.24	42	GPIO7.6
D9	23	GPIO6.25	43	GPIO7.7
D10	20	GPIO6.26	44	GPIO7.8
D11	21	GPIO6.27	45	GPIO7.9
D12	38	GPIO6.28	63	GPIO7.10
D13	39	GPIO6.29	9	GPIO7.11
D14	26	GPIO6.30	32	GPIO7.12
D15	27	GPIO6.31	8	GPIO7.16

Control Pins

• RD: Read signal (any available pin)
• CS: Chip Select (any available pin)
• CONVST: Conversion Start (any available pin)
• BUSY: Busy signal (any interrupt-capable pin)
• RESET: Reset signal (any available pin)

How It Works

Traditional approaches read pins individually:

// SLOW: 16 individual reads
for (int i = 0; i < 16; i++) {
    data |= digitalRead(pins[i]) << i;  // 16 function calls!
}

AD7606p16_t4 reads entire GPIO ports simultaneously:

// FAST: 1 port reads + bit extraction
data = (GPIO6_PSR >> 16) & 0b1111111111111111; // Read D0-D15 from GPIO6
// Extract bits with optimized operations

API Reference

Methods

void getData(int16_t* data)

Gets raw 16-bit ADC readings for all 8 channels.

• Parameters: data - Array of 8 int16_t values to store readings
• Returns: None
• Thread-safe: Yes (uses interrupt disabling)

float getVoltage(uint8_t channel)

Gets voltage reading for a single channel.

• Parameters: channel - Channel number (0-7)
• Returns: Voltage as float (uses configured vRef)
• Thread-safe: Yes (uses interrupt disabling)
• Note: Returns 0.0f for invalid channel numbers

void getVoltages(float* voltages)

Gets voltage readings for all 8 channels at once.

• Parameters: voltages - Array of 8 float values to store voltages
• Returns: None
• Thread-safe: Yes (uses interrupt disabling)
• Note: Uses configured reference voltage from constructor

void reset()

Performs hardware reset of the AD7606.

• Parameters: None
• Returns: None

Performance Goals

1. Minimize ISR duration - library handles this automatically
2. Ability to Call getData() regularly to get latest readings

Supported Boards

• ✅ Teensy 4.1
• ✅ Teensy MicroMod

Examples

• BasicReading: Simple voltage measurement

License

MIT License - see LICENSE file

Contributing

Contributions welcome! Please read CONTRIBUTING.md for guidelines.

Changelog

v0.1.0

• BREAKING: Add configurable vRef parameter to constructor (defaults to 10V)
• FIX: Correct voltage calculation formula (was reading half the actual voltage)
• FIX: Proper 2's complement handling for signed 16-bit values
• Remove debug code from ISR for better performance

v0.0.1 (Initial Release)

• High-speed GPIO port reading implementation
• 200 kSPS conversions per second performance
• Support for Teensy 4.x boards