Skip to main content
Tutorials

Using SparkFun MicroMod M.2 Connectors

SparkFun MicroMod processor boards plug into a carrier board through an M.2 connector. In tscircuit, the carrier-side connector is best modeled as a <connector /> with the m2 standard hint plus MicroMod-specific pin labels.

The important habit is to name the electrical interface first: power rails, reset, boot, I2C, SPI, UART, USB, SDIO, analog pins, PWM pins, and general GPIO. Then you can reuse those names across carrier boards without tying every design to a specific processor module.

References​

Keep the SparkFun pinout open while assigning the exact pin numbers for your board:

Minimal Carrier Connector​

Start by giving the connector a stable name and labeling the signals that your carrier board actually uses. The example below shows a practical subset for a sensor or display carrier: 3.3 V power, ground, I2C, SPI, UART, reset, boot, and two GPIO nets.

const microModPins = {
1: "GND",
2: "V3_3",
3: "I2C_SDA",
4: "I2C_SCL",
5: "SPI_COPI",
6: "SPI_CIPO",
7: "SPI_SCK",
8: "SPI_CS",
9: "UART_TX",
10: "UART_RX",
11: "RESET",
12: "BOOT",
13: "G0",
14: "G1",
} as const

export default () => (
<board width="50mm" height="35mm">
  <connector
    name="J_MICROMOD"
    standard="m2"
    pinLabels={microModPins}
    schPinSpacing="0.65mm"
    schWidth="22mm"
  />
</board>
)
Schematic Circuit Preview

The numbers above are intentionally compact for the example. For production hardware, expand pinLabels to match the full SparkFun MicroMod pinout and keep the names aligned with SparkFun's published signal groups.

Connect a Qwiic Peripheral​

MicroMod carriers commonly expose I2C through Qwiic. Once the M.2 connector labels are in place, route peripherals by net name instead of routing to raw pin numbers.

const microModPins = {
1: "GND",
2: "V3_3",
3: "I2C_SDA",
4: "I2C_SCL",
11: "RESET",
} as const

export default () => (
<board width="50mm" height="35mm">
  <connector
    name="J_MICROMOD"
    standard="m2"
    pinLabels={microModPins}
    pcbX={-10}
    pcbY={0}
  />
  <connector
    name="J_QWIIC"
    pinLabels={{
      1: "GND",
      2: "V3_3",
      3: "I2C_SDA",
      4: "I2C_SCL",
    }}
    footprint="jst-sh-4"
    pcbX={15}
    pcbY={0}
  />
  <trace from=".J_MICROMOD > .I2C_SDA" to=".J_QWIIC > .I2C_SDA" />
  <trace from=".J_MICROMOD > .I2C_SCL" to=".J_QWIIC > .I2C_SCL" />
  <trace from=".J_MICROMOD > .V3_3" to=".J_QWIIC > .V3_3" />
  <trace from=".J_MICROMOD > .GND" to=".J_QWIIC > .GND" />
</board>
)
Schematic Circuit Preview

Reusable MicroMod Connector Component​

For real projects, keep the connector definition in a small reusable component. That makes it easy to share the same MicroMod net names across several carrier boards and to swap a partial pin map for a full one later.

import type { CommonLayoutProps } from "tscircuit"

export const microModCarrierPins = {
  1: "GND",
  2: "V3_3",
  3: "I2C_SDA",
  4: "I2C_SCL",
  5: "SPI_COPI",
  6: "SPI_CIPO",
  7: "SPI_SCK",
  8: "SPI_CS",
  9: "UART_TX",
  10: "UART_RX",
  11: "RESET",
  12: "BOOT",
  13: "G0",
  14: "G1",
} as const

export const MicroModM2Connector = (props: CommonLayoutProps) => (
  <connector
    name="J_MICROMOD"
    standard="m2"
    pinLabels={microModCarrierPins}
    schPinSpacing="0.65mm"
    schWidth="22mm"
    {...props}
  />
)

Use that component inside a carrier board:

import { MicroModM2Connector } from "./MicroModM2Connector"

export default () => (
  <board width="60mm" height="40mm">
    <MicroModM2Connector pcbX={-12} pcbY={0} />
    <led name="D_STATUS" footprint="0603" pcbX={16} pcbY={6} />
    <resistor name="R_STATUS" resistance="1k" footprint="0603" pcbX={16} pcbY={0} />
    <trace from=".J_MICROMOD > .G0" to=".R_STATUS > .pin1" />
    <trace from=".R_STATUS > .pin2" to=".D_STATUS > .anode" />
    <trace from=".D_STATUS > .cathode" to=".J_MICROMOD > .GND" />
  </board>
)

Design Checklist​

  • Use standard="m2" on the carrier connector so downstream tooling knows this is an M.2-style board interface.
  • Copy exact pin numbers from the SparkFun pinout PDF before sending a PCB to fabrication.
  • Keep the net names close to SparkFun's signal names: I2C_SDA, I2C_SCL, SPI_COPI, SPI_CIPO, SPI_SCK, UART_TX, UART_RX, RESET, BOOT, USB_D+, USB_D-, G0, G1, and so on.
  • Prefer named traces such as .J_MICROMOD > .I2C_SDA over raw connector pin references. The schematic stays readable even when the physical pin map grows.
  • Leave unused MicroMod pins out of the first schematic, then add them as your carrier board needs them.