mcp300x-adc-sensor modular resource

The module provides analog-to-digital conversion capabilities for MCP300x SPI ADCs. Tested on MCP3002, MCP3004, and MCP3008 using a Raspberry Pi. If you are using any other board, check out the go modules that are board agnostic: https://app.viam.com/module/hazalmestci/mcp3001-2 and https://app.viam.com/module/hazalmestci/mcp3004-8.

For MCP3002, you can get readings for up to 2 sensors from channel 0 and channel 1. For MCP3004, you can get readings for up to 4 sensors from channel 0 to channel 3. For MCP3008, you can get readings for up to 8 sensors from channel 0 to channel 7.

Wiring for these sensors is different and you should refer to data sheets for each ADC.

Build and run

To use this module, follow the instructions to add a module from the Viam Registry and select the hazalmestci:sensor:mcp300x model from the mcp300x-adc-sensor module.

Configure your mcp300x-adc-sensor

Note

Before configuring your mcp300x-adc-sensor, you must create a machine.

Navigate to the Config tab of your machine's page in the Viam app. Click on the Components subtab and click Create component. Select the sensor type, then select the hazalmestci:sensor:mcp300x model. Click Add module, then enter a name for your sensor and click Create.

On the new component panel, copy and paste the following attribute template into your sensor’s Attributes box:

Note

For more information, see Configure a Machine.

{
  "channel_map": {
    "moisture": 0,
    "temperature": 1,
    "humidity": 2
  }
}

Save your config.

Attributes

The following attributes are available for a mcp300x-adc-sensor sensor:

Name	Type	Inclusion	Description
channel_map	string	Required	The channel map for moisture, temperature, and humidity.

Example configuration

For example, if you have a moisture sensor attached to channel 0, a temperature sensor attached to channel 1, and a humidity sensor attached to channel 2, your config should look like this:

{
    "name": "my-mcp300x",
    "model": "hazalmestci:sensor:mcp300x",
    "type": "sensor",
    "namespace": "rdk",
    "attributes": {
      "channel_map": {
        "moisture": 0,
        "temperature": 1,
        "humidity": 2
      }
    },
    "depends_on": []
}

Since you are getting readings from three separate channels, you won't be able to use the MCP3002 sensor for this use case, and will need either an MCP3004 or an MCP3008.

Next Steps

1. To test your sensor, go to the Control tab and test that you are getting readings.
2. Once you can obtain your readings, configure the data manager to capture and sync the data from all of your machines.
3. To retrieve data captured with the data manager, you can query data with SQL or MQL or visualize it with tools like Grafana.

License

Copyright 2021-2023 Viam Inc.
Apache 2.0