E1M-EVK User Guide

Document

UG-E1M-001

Revision

0.2

Date

June 2026

Status

Preliminary

Download PDFrev 0.2Latest revision

The E1M Development Board (EVK) accelerates evaluation and development on the E1M System-on-Module (SoM) platform by providing a carrier board with common peripherals: USB, Ethernet, CAN, display and camera, audio, sensors, expansion headers, and on-board current measurement points. This guide describes what each interface is, how it is wired on the EVK, and how to use it safely during bring-up.

Purpose and Scope

The E1M Development Board (EVK) accelerates evaluation and development on the E1M System-on-Module (SoM) platform by providing a carrier board with common peripherals: USB, Ethernet, CAN, display and camera, audio, sensors, expansion headers, and on-board current measurement points. This guide describes what each interface is, how it is wired on the EVK, and how to use it safely during bring-up.

The EVK aligns with the E1M platform's unified-pinout approach across module variants described in the internal E1M Standard.

Safety, Handling, and ESD

warning

Handle the EVK and any attached M.2, camera, or display modules under proper ESD controls: grounded wrist strap and ESD mat. Do not hot-plug peripherals unless the interface is explicitly designed for it. USB is generally OK; M.2, display, and camera connectors are not.

1. ESD precautions: grounded wrist strap and ESD mat for every handle.
2. Power precautions: no hot-plug on M.2, display, or camera connectors.
3. Avoid shorts: many signals are routed to exposed headers; an accidental short can damage the SoM or the peripheral.
4. Input voltage: the barrel jack input is rated 7 V to 15 V.
5. Rail domains: the board uses +5V, +3V3, +1V8, and +VIO. Several level shifters make some interfaces voltage-selectable via +VIO.

Functional Overview

From the schematic, the EVK includes the following blocks:

• Power input and tree: barrel jack (7 to 15 V), two USB-C ports, power-good signals on each rail.
• Compute module interface: E1M 35 by 35 module footprint with USB, Ethernet, SDIO/SD, CAN, MIPI DSI/CSI, I2S, PDM, PCIe, UART, ADC/DAC, GPIO, boot pins, JTAG/SWD.
• Networking: 2 RJ45 MagJack (ETH0, ETH1).
• CAN bus: TCAN1044A transceiver, CAN headers, CANH/CANL jumpers (JP1 to JP4).
• Storage: microSD socket plus SDIO muxing to M.2 Key E via 74LVC157.
• Display: 40-pin MIPI DSI connector for RK055HDMIPI4MA0 720p panel.
• Camera: RPi-compatible CSI (15-pin), standard MIPI CSI board-to-board (34-pin), parallel DVP (24-pin); camera mux PI3WVR626, rails +1V2_CAM / +2V6_CAM, 1.8 V level shifting. Camera power rails are adjustable through feedback resistors.
• Audio: two PDM microphones (MP34DT05TR-A), two TAS2563 Class-D amps with JST speaker outputs, I2S source selection via 74LVC157.
• Sensors: ICM-42670-P IMU, BMI323 IMU, BMP581 pressure, TCAL9538 I/O expander.
• Expansion: Arduino and mikroBUS mapping via LSF0108 / LSF0102 level shifters; IO-voltage select header.
• PCIe / M.2: M.2 Key M and Key E, PCIe mux (PI3DBS12212A), refclk buffer (SY75602), I2C mux (TMUX121), TCAL9538 for resets/interrupts.
• Boot and debug: JTAG/SWD 10-pin header (FTSH-105), reset button, BOOT0 to BOOT3 DIP switch, module enable header, U.FL antenna.
• Current measurement: multiple INA236 monitors with shunt resistors and fixed I2C addresses; camera-rail headers P15/P16.

Power System

Power Inputs

Barrel Jack (primary)

The schematic labels the barrel input 7 V to 15 V. The input rail is named +V_BRL.

USB-C Inputs

Two USB-C receptacles are present: J12 and J13. Each provides a VBUS net (USB1_VBUS / USB2_VBUS) and CC pins with 5.1 kΩ resistors.

tip

Use one primary power source at a time during early bring-up (barrel or USB-C) to avoid back-feeding paths unless you have verified the power-OR behavior on your assembled revision.

Main 5 V Generation and Protection

• TPS564247 buck regulator: 5 V 3 A from the barrel input path.
• TPS25210L protection and current-limit switch: produces +5V and 5V_PG power-good.
• LEDs are provided for USB_HOST_VBUS, +3V3, +1V8, +VIO.

Secondary Rails

• TLV62595 buck regulator: generates +3V3 (3V3_PG).
• TLV62595 buck regulator: generates +1V8 (1V8_PG).

SuperCap Rail

A 470 mF SuperCap (C38) sits on the +SCAP rail. The E1M interface symbol exposes pin +S_CAP and routes it in the carrier.

To enable supercap short P10.

warning

Treat the supercap rail as an energy storage node. After power-down it may remain charged. Confirm discharge behavior before handling or probing.

Boot, Reset, and Debug

Debug Connectors

• J2: 10-pin debug header (FTSH-105) with JTAG / SWD signals: TCK/SWDCLK, TMS/SWDIO, TDI, TDO, JTAG_RST, plus GND and +VIO.
• J3: secondary debug connector labeled "Debug" (SKEDD). Not populated on the 2626-R2 (E1M-AEN) build; use J2 for SWD/JTAG. See Appendix B.

JTAG and Boot Switch

Reset

S1 is the reset switch, labeled MCU_RST. See JTAG and boot switch.

Module-side pulls

Reset pin has an internal pull-up.

Boot Mode Selection

SW1 is a DIP switch exposing BOOT0, BOOT1, BOOT2, BOOT3. See JTAG and boot switch.

Module-side pulls

Pull-up or pull-down for the boot pins must be provided inside the module (schematic annotation). The EVK only exposes the switches.

warning

10K resistors are used as a placeholder, actual value and configuration may differ according to the specific E1M module. Refer to the datasheet.

Module Enable / Standby

• P12 header: "Short to disable module" (MODULE_EN control).
• P14 header: "Short to put the module in sleep mode" (MODULE_STBY control).

See JTAG and boot switch.

Antenna

J1 is a U.FL / IPEX connector labeled ANT, with an ONE mXTEND antenna network footprint on the board.

USB Subsystem

USB-C Ports

J12 and J13 are USB-C connectors. USB2 is labeled "USB HOST" at the CC-resistor pair (R19/R20).

USB-A Host Port

J11 is a USB-A connector. Host VBUS is gated by TPS25221 (reverse-current blocking when disabled); output net is USB_HOST_VBUS.

Data Mux and Host ID

• U10 TMUXHS221: high-speed mux on the USB data lines.
• P2 header labeled "Short for USB HOST" tied to USB1_ID.

tip

If your software expects OTG / role selection via the ID pin, use P2 to force the intended role (host).

Ethernet

• J8: ETH0, Bel ARJM11C7-502-KB-EW2 integrated MagJack.
• J20: ETH1, same connector.
• Differential pairs ETHx_DA / DB / DC / DD and LED signals are routed.
• Shield network includes caps and high-value resistors to chassis.

CAN Bus

Transceiver

U6 TCAN1044AVDRBRQ1: signals CAN_TXD, CAN_RXD, CAN_STBY, CANH, CANL.

Headers and Jumpers

• JP1 to JP4: CANH/CANL and CAN TX/RX routing jumpers.
• J9: 2-pin plus shield/ground CAN pigtail connector.

tip

Confirm whether the 120 Ω termination is populated on your BOM variant before connecting to an existing CAN network. Leaving a second terminator on a fully-terminated bus halves the effective impedance.

microSD and SDIO Muxing

microSD Socket

J7: push-push microSD with SD_CLK, SD_CMD, SD_D0 to SD_D3, SD_DET.

note

On the 2626-R2 (E1M-AEN) build the per-line ESD diodes on the SD bus (D12–D14, D27–D30, ESD9101P2T5G) are not populated. The footprints remain for builds that require board-level ESD protection on the card edge. See Appendix B.

SDIO Multiplexing

Two 74LVC157 muxes (U38 and U39) implement SDIO selection between the microSD socket and M.2 Key E SDIO. Control lines are MUX_SEL.SDIO and MUX_EN. Jumpers JP5 / JP6 sit near the M.2 SDIO reset selection.

tip

Decide whether SDIO should route to the microSD socket or to M.2 Key E (SDIO-based Wi-Fi modules) by setting the mux-control jumpers for your use case.

Display (MIPI DSI)

• J6: 40-pin display connector; the sheet references RK055HDMIPI4MA0.
• MIPI DSI clock + 4 data lanes (pairs) are routed.
• Backlight pins: BL_LED_A, BL_LED_K.
• Touch: CTP_INT, CTP_RST, plus level-shifted variants and pullups.
• I2C pullups are called out explicitly on the display sheet.

Camera Interfaces

RPi-Compatible CSI

J5: 15-pin "RP-Compatible" connector; CSI CLK + two data lane pairs.

Standard MIPI Camera B2B

J4: 34-pin board-to-board camera connector; a power-up sequence is annotated on the sheet.

Parallel (DVP) Camera

J22: 24-pin connector for a low-power parallel camera with CAM_D0 to CAM_D7, CAM_PCLK, CAM_XVCLK, CAM_HSYNC, CAM_VSYNC.

Camera Switching, Rails, and Level Shifting

• U1 PI3WVR626: CSI lane switching between A / B ports.
• Camera rails: +1V2_CAM, +2V6_CAM.

• U36 TXB0108: shifts camera control signals to 1.8 V (e.g. CAM_RST_1V8).

• LSF0102 I2C level shifters exist for CSI / DSI I2C rails.

PCIe and M.2 Expansion

Not fitted on the E1M-AEN build

The Alif Ensemble SoCs have no PCIe, so on the 2626-R2 (E1M-AEN) assembly the M.2 card-edge connectors are not populated: J16 (Key E) and J23 (Key M), together with their PCIe AC-coupling and termination (C93–C100, R73, R74, R76, R123). The PCIe switch / buffer / I²C-mux support ICs described below remain populated for forward-compatibility with future PCIe-capable SoMs. See Appendix B for the full not-populated list.

M.2 Key M

J23: NVMe / PCIe Key M connector, multiple PCIe lanes and sidebands.

M.2 Key E

J16: Wi-Fi / BT Key E connector. Schematic notes reference standard M.2 usage: PCIe or SDIO for Wi-Fi; UART and PCM; I2C and ALERTn; NFC.

PCIe Reference Clock and Switching

• SY75602: PCIe clock buffer.
• PI3DBS12212A: PCIe lane mux / switch.
• TMUX121: PCIe I2C mux.

PCIe I/O Expander

U37 TCAL9538: exposes PCIE_IO_EXP.INT and PCIE_IO_EXP.RST for the M.2 slots.

Audio

PDM Microphones

MP34DT05TR-A on MIC0 and MIC1 via the PDM_Cx / PDM_Dx clock/data nets.

Amplifiers and Speaker Outputs

• U27, U28: TAS2563 Class-D smart-amp ICs.
• Speaker outputs routed to J14 and J21 (2-pin JST connectors).
• Control: AMP.ENABLE, AMP.FAULT.

I2S Routing

U46 74LVC157 selects the I2S source. Control nets: I2S_EN, I2S_SELECT. I2S can be sourced either from the module or from M.2 Key E (M2E_I2S nets): useful for BT audio paths.

Sensors and I/O Expansion

Sensor Devices

Ref	Part	Role
U12	ICM-42670-P	6-axis IMU
U13	BMI323	6-axis IMU
U14	BMP581	Barometric pressure

I2C Bus and Pullups

The board uses I2C0.SCL / I2C0.SDA as a shared bus for sensors and current monitors. I2C pullups are called out on the sensors sheet.

I/O Expander

U35 TCAL9538 drives LCD_PWR_EN, LCD_RST, CTP_RST, CAM_EN, and sensor interrupts. It exposes IO_EXP.INT / IO_EXP.RST to the module.

Current Measurement (Power Profiling)

The EVK includes multiple INA236 current monitors with shunts and fixed I2C addresses. Variants on the BOM are INA236AIYBJR and INA236BIYBJR.

• Shunt examples: 50 mΩ and 20 mΩ.
• Max-current relation annotated on the sheet: I_max = 81.92 mV / R
• P15 / P16 headers relate to camera-rail measurement nodes (+V_CAM0, +V_CAM1).

tip

Use the INA236 monitors to log rail consumption during boot, radio activity, display usage, and camera streaming: especially useful for comparing firmware power states or module variants side-by-side.

User Interface

• Rotary encoder: PEC12R-4222F-S0024, with switch and quadrature signals.
• RGB LED: 150505M173300, driven via transistors.
• DAC outputs: DAC0_OUT, DAC1_OUT buffered by OPA189 op-amps, routed to header J15.
• Comparator signals: CMP0, CMP1 on header J18.
• IO-voltage select header P17: +1V8, +V_ANA, +3V3, +5V.

Arduino / mikroBUS Expansion

The schematic includes an "Arduino / Mikro BUS" sheet mapping signals to headers using LSF0108 and LSF0102 level shifters. The IO-voltage header selects the domain for expansion interfaces.

info

Decide your +VIO level before attaching external shields or click boards: an over-voltage on IO can damage attached peripherals.

Recommended Bring-Up Checklist

note

This is recommended engineering practice, not a verbatim procedure from the schematic.

1. Visual inspection: check for solder bridges around the module footprint, M.2 connectors, and fine-pitch camera / display FFCs.
2. Power-only test (no peripherals):
   • Apply barrel input within 7 V to 15 V.
   • Verify LEDs for +3V3, +1V8, +VIO, USB_HOST_VBUS.
   • Probe 5V_PG, 3V3_PG, 1V8_PG at the indicated test points.
3. Module enable: ensure MODULE_EN is not held low (P12 is "short to disable module").
4. Boot configuration: set BOOT0 to BOOT3 on SW1 per your SoM firmware.
5. Debug access: connect to J2 (SWD/JTAG) and confirm the IO reference voltage (+VIO on header).
6. Add peripherals one at a time: Ethernet, microSD, then display / camera, then M.2 modules.

Known Design Notes

From schematic annotations:

• Power sheet: Check voltage division: it boots at 13 V.
• Boot sheet: Pull-up or pull-down for the boot pins must be in the module.

These notes should be carried forward into the production release notes and errata.

Appendix A: Interface Quick Reference

Table: EVK interface summary

Block	Whats on the board
Power	Barrel 7 to 15 V, +5V / +3V3 / +1V8 / +VIO rails, PG signals, +SCAP supercap
USB	2 USB-C, 1 USB-A host, HS mux, host-ID strap
Ethernet	2 RJ45 MagJack (ARJM11C7-502-KB-EW2)
CAN	TCAN1044A transceiver plus JP1 to JP4 jumpers and J9
Storage	microSD plus SDIO mux to M.2 Key E
Display	40-pin MIPI-DSI (RK055HDMIPI4MA0), touch RST/INT
Camera	RPi CSI 15-pin, MIPI B2B 34-pin, DVP 24-pin, camera mux plus rails
Audio	2 PDM mic, 2 TAS2563, I2S mux, JST speaker headers
Sensors	ICM-42670-P, BMI323, BMP581, TCAL9538 I/O expander
PCIe/M.2	Key M plus Key E, PCIe lane mux, refclk buffer, I2C mux
Debug	J2 SWD/JTAG, reset, BOOT0 to BOOT3, P12/P14, U.FL antenna
Expansion	Arduino plus mikroBUS, IO-voltage select
Profiling	INA236 monitors with shunts and fixed I2C addresses

Appendix B: Assembly Variant — E1M-AEN (Alif) Build

The E1M EVK carrier is laid out to the full E1M standard (superset) pinout. When assembled for an E1M-AEN (Alif Ensemble) module, the features that the SoM does not expose are left unpopulated. The list below is taken from the 2626-R2 BOM (35 not-populated designators); footprints remain on the PCB so the same carrier can be rebuilt for other E1M variants.

Table: Not-populated components — 2626-R2 (E1M-AEN) build

Designator(s)	Function	Reason not fitted
J16, J23	M.2 Key E / Key M card-edge connectors	Alif Ensemble has no PCIe; the M.2 slots are unused.
C93–C100, R73, R74, R76, R123	PCIe lane / ref-clock AC-coupling and termination	Support the unfitted M.2 slots.
D12–D14, D27–D30	microSD line ESD diodes (ESD9101P2T5G)	Optional card-edge ESD protection; omitted on this build.
J3	Secondary Debug connector (SKEDD)	Primary SWD/JTAG is J2; the secondary header is unused.
L4, R111	On-board antenna feed (22 nH inductor, 0 Ω jumper)	AEN uses the module RF path / J1 U.FL; the on-board feed is open.
R5, R10, R11, R24, R46, R47, R50, R75, R145, R181, R200	Configuration jumpers and pull resistors	Build-time options left open on the AEN assembly.

Release History

Table: Release History

Revision	Changes	Date
0.1	Initial draft	April - 2026
0.2	Documented the 2626-R2 assembly variant: not-populated components for the E1M-AEN (Alif) build (M.2 Key E/M connectors and PCIe AC-coupling, microSD ESD diodes, secondary debug J3, antenna feed, option jumpers). Added Appendix B and inline notes.	June - 2026