The MAX11205PMB1 peripheral module provides the necessary hardware to interface the MAX11205 16-bit ADC to any system that utilizes Pmod™-compatible expansion ports configurable for GPIO interface. The IC is an ultra-low-power (< 300µA max active current), high-resolution, serial-output ADC. This device provides the highest resolution per unit power in the industry and is optimized for applications that require very high dynamic range with low power, such as sensors on a 4mA to 20mA industrial control loop. The voltage reference for the IC is supplied by a MAX6037 (2.5V) that is also on the module. The filtered power-supply voltage from the host can be optionally passed (jumper selectable) through a MAX8510 ultra-low-noise LDO, allowing empirical evaluation of performance with different power sources.
The MAX11205PMB1 board has to be supplied with a voltage between 1.7V and +3.6V . If using directly with a PMOD connector, the host board should be capable of providing the 3.3V supply.
The PMOD interface is a series of standardized digital interfaces for various digital communication protocols such as SPI, I2C, and UART. These interface types were standardized by Digilent, which is now a division of National Instruments. Complete details on the PMOD specification can be found here.
The specific interface used for the MAX11205PMB1 boards is SPI.
P1 Pin Number | Pin Function | Mnemonic |
---|---|---|
Pin 1 | N.C. | CS |
Pin 2 | N.C. | MOSI |
Pin 3 | Master In Slave Out | MISO |
Pin 4 | Serial Clock | SCLK |
Pin 5 | Digital Ground | DGND |
Pin 6 | Digital Power | VDD |
The goal of ADI Microcontroller No-OS is to be able to provide reference projects for lower end processors, which can't run Linux, or aren't running a specific operating system, to help those customers using microcontrollers with ADI parts. ADI No-OS offers generic drivers which can be used as a base for any microcontroller platform and also example projects which are using these drivers on various microcontroller platforms.
For more information about ADI No-OS and supported microcontroller platforms see: no-OS
Information about the MAX11205 driver can be found here: MAX11205 driver
The MAX32655 does not have a PMOD interface, but you may use Dupont male-female cables to make the required connections. The following table shows how the connection between MAX11205PMB1 and MAX32655 is realized in this project example.
P1 MAX11205PMB1 Pin Number | MAX32655 Pin Number | Function | Mnemonic |
---|---|---|---|
Pin 1 | N.C. | - | - |
Pin 2 | N.C. | - | - |
Pin 3 | MISO | Master In Slave Out | MISO |
Pin 4 | SCLK | Serial Clock | SCLK |
Pin 5 | GND | Digital Ground | DGND |
Pin 6 | POWER 3.3V | Digital Power | VDD |
Pin 3 | P1_6 | Data Ready | DRDY |
Clone NO-OS with the --recursive
flag:
git clone --recursive https://github.com/analogdevicesinc/no-OS
If however you've already cloned NO-OS without the --recursive
flag, you may initialize all the submodules in an existing NO-OS clone with:
git submodule update --recursive --init
Please follow the steps below for No-OS Setup based on the environment you are using. Make sure you use the information for the specific platform you are using (e.g. MAXIM).
Prior to building a no-OS project, it is required to set up some environment variables so that the build process may find the necessary tools (compiler, linker, SDK etc.).
Use the following commands to prepare your environment for building no-OS projects:
The path of the project is no-OS/projects/max11205pmb1/
Go in the project directory that should be built.
The build process creates a build directory in the project folder:
build ├── app ├── bsp ├── obj ├── project_name.elf └── tmp
Once the .elf
, .hex
or .bin
file has been generated, make sure the board is powered on, JTAG cable connected and use the following commands to upload the program to the board or debug.
Uploading the binary to target is generically achieved with:
$ make run
Use the following command to launch the SDK associated to the used platform in order to be able to debug graphically by clicking the debug button:
$ make sdkopen
Fore more details about the available make rules, check out this page.
In order to build the dummy project make sure you have the following configuration in the Makefile:
# Select the example you want to enable by choosing y for enabling and n for disabling BASIC_EXAMPLE = y IIO_EXAMPLE = n
When running make command make sure to specify the platform you want to build the project for.
The basic project contains the generic HAL initialization of the used platform, together with the SPI, IRQ and UART driver configuration and initialization.
The SPI driver is used to communicate with the MAX11205PMB1 device, the IRQ driver is used to sample data when the conversion finishes (signaled by MISO line) and the UART driver is used to display on the host machine the measured data.
The dummy project contains the MAX11205 driver initialization:
struct no_os_irq_init_param max11205_gpio_irq_ip = { .platform_ops = GPIO_IRQ_OPS, .irq_ctrl_id = GPIO_CTRL_IRQ_ID, .extra = GPIO_IRQ_EXTRA, }; struct no_os_spi_init_param max11205_spi_ip = { .device_id = SPI_DEVICE_ID, .max_speed_hz = SPI_BAUDRATE, .bit_order = NO_OS_SPI_BIT_ORDER_MSB_FIRST, .mode = NO_OS_SPI_MODE_2, .platform_ops = SPI_OPS, .chip_select = SPI_CS, .extra = SPI_EXTRA, }; struct no_os_gpio_init_param max11205_gpio_rdy_ip = { .port = GPIO_SYNC_PORT_NUM, .number = GPIO_SYNC_PIN_NUM, .pull = NO_OS_PULL_NONE, .platform_ops = GPIO_OPS, .extra = GPIO_EXTRA, }; struct max11205_init_param max11205_ip = { .gpio_rdy = &max11205_gpio_rdy_ip, .vref_mv = MAX11205_VREF_MV, }; /* Initialize GPIO IRQ controller */ ret = no_os_irq_ctrl_init(&max11205_gpio_irq_desc, &max11205_gpio_irq_ip); if (ret) return ret; /* Initialize device */ max11205_ip.irq_ctrl = max11205_gpio_irq_desc; max11205_ip.spi_init = max11205_spi_ip; ret = max11205_init(&max11205_desc, max11205_ip); if (ret) return ret;
After the initialization phase, the device starts performing measurements which are accessed continuously in a while loop and are written on UART.
/* Continuously read data */ while (1) { ret = max11205_get_data_raw(max11205_desc, &new_data_avail, &adc_data_raw); if (ret) return ret; /* Print data only if new data is available */ if (new_data_avail) { pr_info("ADC raw data %d:\n", adc_data_raw); ret = max11205_get_data_mv(max11205_desc, adc_data_raw, &adc_data_mv); if (ret) return ret; pr_info("ADC converted data %d [mV]:\n", adc_data_mv); } }
UART Output for V_REF=3200 [mV], with V_IN=1300 [mV]:
ADC raw data 13097: ADC converted data 1279 [mV]:
In order to build the IIO project make sure you have the following configuration in the Makefile:
# Select the example you want to enable by choosing y for enabling and n for disabling BASIC_EXAMPLE = n IIO_EXAMPLE = y
When running make command make sure to specify the platform you want to build the project for.
This project is actually a TINYIIOD demo for MAX11205PMB1 board. The project launches a TINYIIOD server on the board so that the user may connect to it via an IIO client. Using IIO-Oscilloscope, the user can view the measured data on a plot.
If you are not familiar with ADI IIO Application, please take a look at: IIO No-OS
This IIO Project uses IIO-Oscilloscope as a client. If you are not familir with ADI IIO-Oscilloscope Client, please take a look at: IIO Oscilloscope
The No-OS IIO Application together with the No-OS IIO MAX11205 driver take care of all the backend logic needed to setup the IIO server. The user has to initialize the IIO device and call the IIO app as shown below. The read buffer is used for storing data which shall be available on the plot in the IIO Oscilloscope Client.
#define DATA_BUFFER_SIZE 400 uint8_t iio_data_buffer[DATA_BUFFER_SIZE * sizeof(int16_t)]; struct iio_data_buffer accel_buff = { .buff = (void *)iio_data_buffer, .size = DATA_BUFFER_SIZE * sizeof(int16_t) }; struct no_os_irq_init_param max11205_gpio_irq_ip = { .platform_ops = GPIO_IRQ_OPS, .irq_ctrl_id = GPIO_CTRL_IRQ_ID, .extra = GPIO_IRQ_EXTRA, }; struct no_os_spi_init_param max11205_spi_ip = { .device_id = SPI_DEVICE_ID, .max_speed_hz = SPI_BAUDRATE, .bit_order = NO_OS_SPI_BIT_ORDER_MSB_FIRST, .mode = NO_OS_SPI_MODE_2, .platform_ops = SPI_OPS, .chip_select = SPI_CS, .extra = SPI_EXTRA, }; struct no_os_gpio_init_param max11205_gpio_rdy_ip = { .port = GPIO_SYNC_PORT_NUM, .number = GPIO_SYNC_PIN_NUM, .pull = NO_OS_PULL_NONE, .platform_ops = GPIO_OPS, .extra = GPIO_EXTRA, }; struct max11205_init_param max11205_ip = { .gpio_rdy = &max11205_gpio_rdy_ip, .vref_mv = MAX11205_VREF_MV, }; int ret; struct max11205_iio_dev *max11205_iio_desc; struct max11205_iio_dev_init_param max11205_iio_ip; struct no_os_irq_ctrl_desc *max11205_gpio_irq_desc; /* Initialize GPIO IRQ controller */ ret = no_os_irq_ctrl_init(&max11205_gpio_irq_desc, &max11205_gpio_irq_ip); if (ret) return ret; /* Initialize device */ max11205_ip.irq_ctrl = max11205_gpio_irq_desc; max11205_ip.spi_init = max11205_spi_ip; max11205_iio_ip.max11205_dev_init = &max11205_ip; max11205_iio_ip.dev_id = MAX11205A; ret = max11205_iio_init(&max11205_iio_desc, &max11205_iio_ip); if (ret) return ret; struct iio_app_device iio_devices[] = { { .name = "max11205a", .dev = max11205_iio_desc, .dev_descriptor = max11205_iio_desc->iio_dev, .read_buff = &accel_buff, } }; return iio_app_run(iio_devices, NO_OS_ARRAY_SIZE(iio_devices));
After flashing and running the application, IIO Oscilloscope can be used to obtain the desired data. Below you may find some snippets from IIO Oscilloscope, when running IIO Project:
Bellow you can see the Connection window for IIO Oscilloscope. The handshake is performed and the device is detected over UART. After pressing the Connect button we can see the device in the list, together with its channels and we can see the measured data.
Below you can see the Simple View which contains the read data from the ADC. Observe how the measurements change when changing the V_IN value.
Below you can see the Debug View which contains the list of attributes for the voltage channel.
Below you can see the Plot View for the converted data. The Plot view shows the raw vales measured by the ADC. Observe how the measurements change when changing the V_IN value.