# 2. Micro node hardware

Micro node is the smallest CAN-PWM converter designed to control 1 - 2 ESC or servo with an external power.

Micro node may power the servo, but it is not recommended, since, due to the lack of its own DC-DC, the entire load will go to the device that powers the micro node. If you need to power a servo, it is recommended to look at mini node.

This page is about hardware specific details. For general information, refer to the 1. General page., for software related details please refer Cyphal interface or DroneCAN interface.

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drawing drawing drawing

# 2.1. Features

# 2.2. Wire

Schematic features. Schematic can be provided via issue.

Connectors

The node has 3 connectors which are described in the table below.

Connector Description
1 CAN1, CAN2 Devices that deliver power to the bus are required to provide 4.5–5.5 V on the bus power line, 5.0 V nominal. Devices that are powered from the bus should expect 4.5–5.5 V on the bus power line. The current shall not exceed 1 A per connector.
2 SWD STM32 firmware updating using programmer-sniffer.
3 PWM1, PWM2 Connectors should be used to deliver signal and power (below 1 amp) to payload such as SERVO or ESC (without power delivery)

Here you can find manufacturer part number of connectors it self and its mates.

Type MP Suitable Wire Type MP
CAN1 JST SM04B-GHS-TB(LF)(SN) JST 4-pins cable (opens new window) JST GHR-04V-S (opens new window) and pin SSHL-002T-P0.2 (opens new window)
CAN2 JST SM04B-GHS-TB(LF)(SN) JST 4-pins cable (opens new window) JST GHR-04V-S (opens new window) and pin SSHL-002T-P0.2 (opens new window)
PWM1 B-2100S03P-A110 Dupont 3-Pin Connector
PWM2 B-2100S03P-A110 Dupont 3-Pin Connector
SWD JST SM04B-GHS-TB(LF)(SN) JST 4-pins cable (opens new window) JST GHR-04V-S (opens new window) and pin SSHL-002T-P0.2 (opens new window)

Pin configuration and functions

Pin N CAN1, CAN2 SWD PWM1, PWM2
1 5V in GND GND
2 CAN High SWCLK 5V
3 CAN Low SWDIO PWM1, PWM2
4 GND 3.3V

# 2.3. Specifications

Mechanical

Scheme is shown on the picture below.

micro_schematic

Width, mm Length, mm Height, mm
Outline 13.5 35.9 10.3
PCB 13.5 27.6 1.6

Total weight of device 3 g (with cable 4.4g)

You can download 3D model on GrabCAD (opens new window)

Absolute Maximum Ratings

Parameter MIN MAX UNIT
V (CAN1, CAN2) 4.5 5.5 V
I max 1 A
Operating temperature -40 +60 C

Recommended operating conditions

Parameter VALUE UNIT
V (CAN1, CAN2) 5 V
Operating temperature +20 C

ESD ratings

Description Value UNIT
Human-body model (HBM) 2000 V
Charged-device model (CDM) 500 V

# 2.4. Description

# Pinout

Here you can see all connections of MCU.

micro_v1_pinout

# Functional Block Diagram

# Connection example diagram

micro_wire

# 2.5. Power Supply Recommendations

The uNODE is designed to operate from an input voltage supply range between 4.5 V and 5.5 V. This input supply must be able to withstand the maximum input current and maintain a stable voltage. The resistance of the input supply rail should be low enough that an input current transient does not cause a high enough drop that can cause a false UVLO fault triggering and system reset. The amount of bulk capacitance is not critical, but a 47-μF or 100-μF electrolytic capacitor is a typical choice.

# 2.6. Revision history

Version Date Description
v1.2.2 (opens new window) Sep 9, 2022 Fix PWM1 and PWM2 typo, add hardware version on the board.
v1.2.1 (opens new window) Aug 31, 2022 Typo mistake: PWM1 and PWM2 are mixed up, harware version is missing. Updates: Add RGB led.
v1.1 (opens new window) Dec 17, 2021 The first release